psql(1) PostgreSQL 15.8 Documentation psql(1)
NAME
psql - PostgreSQL interactive terminal
SYNOPSIS
psql [option...] [dbname [username]]
DESCRIPTION
psql is a terminal-based front-end to PostgreSQL. It enables you to
type in queries interactively, issue them to PostgreSQL, and see the
query results. Alternatively, input can be from a file or from command
line arguments. In addition, psql provides a number of meta-commands
and various shell-like features to facilitate writing scripts and
automating a wide variety of tasks.
OPTIONS
-a
--echo-all
Print all nonempty input lines to standard output as they are read.
(This does not apply to lines read interactively.) This is
equivalent to setting the variable ECHO to all.
-A
--no-align
Switches to unaligned output mode. (The default output mode is
aligned.) This is equivalent to \pset format unaligned.
-b
--echo-errors
Print failed SQL commands to standard error output. This is
equivalent to setting the variable ECHO to errors.
-c command
--command=command
Specifies that psql is to execute the given command string,
command. This option can be repeated and combined in any order with
the -f option. When either -c or -f is specified, psql does not
read commands from standard input; instead it terminates after
processing all the -c and -f options in sequence.
command must be either a command string that is completely parsable
by the server (i.e., it contains no psql-specific features), or a
single backslash command. Thus you cannot mix SQL and psql
meta-commands within a -c option. To achieve that, you could use
repeated -c options or pipe the string into psql, for example:
psql -c '\x' -c 'SELECT * FROM foo;'
or
echo '\x \\ SELECT * FROM foo;' | psql
(\\ is the separator meta-command.)
Each SQL command string passed to -c is sent to the server as a
single request. Because of this, the server executes it as a single
transaction even if the string contains multiple SQL commands,
unless there are explicit BEGIN/COMMIT commands included in the
string to divide it into multiple transactions. (See
Section 55.2.2.1 for more details about how the server handles
multi-query strings.)
If having several commands executed in one transaction is not
desired, use repeated -c commands or feed multiple commands to
psql's standard input, either using echo as illustrated above, or
via a shell here-document, for example:
psql <<EOF
\x
SELECT * FROM foo;
EOF
--csv
Switches to CSV (Comma-Separated Values) output mode. This is
equivalent to \pset format csv.
-d dbname
--dbname=dbname
Specifies the name of the database to connect to. This is
equivalent to specifying dbname as the first non-option argument on
the command line. The dbname can be a connection string. If so,
connection string parameters will override any conflicting command
line options.
-e
--echo-queries
Copy all SQL commands sent to the server to standard output as
well. This is equivalent to setting the variable ECHO to queries.
-E
--echo-hidden
Echo the actual queries generated by \d and other backslash
commands. You can use this to study psql's internal operations.
This is equivalent to setting the variable ECHO_HIDDEN to on.
-f filename
--file=filename
Read commands from the file filename, rather than standard input.
This option can be repeated and combined in any order with the -c
option. When either -c or -f is specified, psql does not read
commands from standard input; instead it terminates after
processing all the -c and -f options in sequence. Except for that,
this option is largely equivalent to the meta-command \i.
If filename is - (hyphen), then standard input is read until an EOF
indication or \q meta-command. This can be used to intersperse
interactive input with input from files. Note however that Readline
is not used in this case (much as if -n had been specified).
Using this option is subtly different from writing psql < filename.
In general, both will do what you expect, but using -f enables some
nice features such as error messages with line numbers. There is
also a slight chance that using this option will reduce the
start-up overhead. On the other hand, the variant using the shell's
input redirection is (in theory) guaranteed to yield exactly the
same output you would have received had you entered everything by
hand.
-F separator
--field-separator=separator
Use separator as the field separator for unaligned output. This is
equivalent to \pset fieldsep or \f.
-h hostname
--host=hostname
Specifies the host name of the machine on which the server is
running. If the value begins with a slash, it is used as the
directory for the Unix-domain socket.
-H
--html
Switches to HTML output mode. This is equivalent to \pset format
html or the \H command.
-l
--list
List all available databases, then exit. Other non-connection
options are ignored. This is similar to the meta-command \list.
When this option is used, psql will connect to the database
postgres, unless a different database is named on the command line
(option -d or non-option argument, possibly via a service entry,
but not via an environment variable).
-L filename
--log-file=filename
Write all query output into file filename, in addition to the
normal output destination.
-n
--no-readline
Do not use Readline for line editing and do not use the command
history (see the section called "Command-Line Editing" below).
-o filename
--output=filename
Put all query output into file filename. This is equivalent to the
command \o.
-p port
--port=port
Specifies the TCP port or the local Unix-domain socket file
extension on which the server is listening for connections.
Defaults to the value of the PGPORT environment variable or, if not
set, to the port specified at compile time, usually 5432.
-P assignment
--pset=assignment
Specifies printing options, in the style of \pset. Note that here
you have to separate name and value with an equal sign instead of a
space. For example, to set the output format to LaTeX, you could
write -P format=latex.
-q
--quiet
Specifies that psql should do its work quietly. By default, it
prints welcome messages and various informational output. If this
option is used, none of this happens. This is useful with the -c
option. This is equivalent to setting the variable QUIET to on.
-R separator
--record-separator=separator
Use separator as the record separator for unaligned output. This is
equivalent to \pset recordsep.
-s
--single-step
Run in single-step mode. That means the user is prompted before
each command is sent to the server, with the option to cancel
execution as well. Use this to debug scripts.
-S
--single-line
Runs in single-line mode where a newline terminates an SQL command,
as a semicolon does.
Note
This mode is provided for those who insist on it, but you are
not necessarily encouraged to use it. In particular, if you mix
SQL and meta-commands on a line the order of execution might
not always be clear to the inexperienced user.
-t
--tuples-only
Turn off printing of column names and result row count footers,
etc. This is equivalent to \t or \pset tuples_only.
-T table_options
--table-attr=table_options
Specifies options to be placed within the HTML table tag. See \pset
tableattr for details.
-U username
--username=username
Connect to the database as the user username instead of the
default. (You must have permission to do so, of course.)
-v assignment
--set=assignment
--variable=assignment
Perform a variable assignment, like the \set meta-command. Note
that you must separate name and value, if any, by an equal sign on
the command line. To unset a variable, leave off the equal sign. To
set a variable with an empty value, use the equal sign but leave
off the value. These assignments are done during command line
processing, so variables that reflect connection state will get
overwritten later.
-V
--version
Print the psql version and exit.
-w
--no-password
Never issue a password prompt. If the server requires password
authentication and a password is not available from other sources
such as a .pgpass file, the connection attempt will fail. This
option can be useful in batch jobs and scripts where no user is
present to enter a password.
Note that this option will remain set for the entire session, and
so it affects uses of the meta-command \connect as well as the
initial connection attempt.
-W
--password
Force psql to prompt for a password before connecting to a
database, even if the password will not be used.
If the server requires password authentication and a password is
not available from other sources such as a .pgpass file, psql will
prompt for a password in any case. However, psql will waste a
connection attempt finding out that the server wants a password. In
some cases it is worth typing -W to avoid the extra connection
attempt.
Note that this option will remain set for the entire session, and
so it affects uses of the meta-command \connect as well as the
initial connection attempt.
-x
--expanded
Turn on the expanded table formatting mode. This is equivalent to
\x or \pset expanded.
-X
--no-psqlrc
Do not read the start-up file (neither the system-wide psqlrc file
nor the user's ~/.psqlrc file).
-z
--field-separator-zero
Set the field separator for unaligned output to a zero byte. This
is equivalent to \pset fieldsep_zero.
-0
--record-separator-zero
Set the record separator for unaligned output to a zero byte. This
is useful for interfacing, for example, with xargs -0. This is
equivalent to \pset recordsep_zero.
-1
--single-transaction
This option can only be used in combination with one or more -c
and/or -f options. It causes psql to issue a BEGIN command before
the first such option and a COMMIT command after the last one,
thereby wrapping all the commands into a single transaction. If any
of the commands fails and the variable ON_ERROR_STOP was set, a
ROLLBACK command is sent instead. This ensures that either all the
commands complete successfully, or no changes are applied.
If the commands themselves contain BEGIN, COMMIT, or ROLLBACK, this
option will not have the desired effects. Also, if an individual
command cannot be executed inside a transaction block, specifying
this option will cause the whole transaction to fail.
-?
--help[=topic]
Show help about psql and exit. The optional topic parameter
(defaulting to options) selects which part of psql is explained:
commands describes psql's backslash commands; options describes the
command-line options that can be passed to psql; and variables
shows help about psql configuration variables.
EXIT STATUS
psql returns 0 to the shell if it finished normally, 1 if a fatal error
of its own occurs (e.g., out of memory, file not found), 2 if the
connection to the server went bad and the session was not interactive,
and 3 if an error occurred in a script and the variable ON_ERROR_STOP
was set.
USAGE
Connecting to a Database
psql is a regular PostgreSQL client application. In order to connect to
a database you need to know the name of your target database, the host
name and port number of the server, and what user name you want to
connect as. psql can be told about those parameters via command line
options, namely -d, -h, -p, and -U respectively. If an argument is
found that does not belong to any option it will be interpreted as the
database name (or the user name, if the database name is already
given). Not all of these options are required; there are useful
defaults. If you omit the host name, psql will connect via a
Unix-domain socket to a server on the local host, or via TCP/IP to
localhost on machines that don't have Unix-domain sockets. The default
port number is determined at compile time. Since the database server
uses the same default, you will not have to specify the port in most
cases. The default user name is your operating-system user name, as is
the default database name. Note that you cannot just connect to any
database under any user name. Your database administrator should have
informed you about your access rights.
When the defaults aren't quite right, you can save yourself some typing
by setting the environment variables PGDATABASE, PGHOST, PGPORT and/or
PGUSER to appropriate values. (For additional environment variables,
see Section 34.15.) It is also convenient to have a ~/.pgpass file to
avoid regularly having to type in passwords. See Section 34.16 for more
information.
An alternative way to specify connection parameters is in a conninfo
string or a URI, which is used instead of a database name. This
mechanism give you very wide control over the connection. For example:
$ psql "service=myservice sslmode=require"
$ psql postgresql://dbmaster:5433/mydb?sslmode=require
This way you can also use LDAP for connection parameter lookup as
described in Section 34.18. See Section 34.1.2 for more information on
all the available connection options.
If the connection could not be made for any reason (e.g., insufficient
privileges, server is not running on the targeted host, etc.), psql
will return an error and terminate.
If both standard input and standard output are a terminal, then psql
sets the client encoding to "auto", which will detect the appropriate
client encoding from the locale settings (LC_CTYPE environment variable
on Unix systems). If this doesn't work out as expected, the client
encoding can be overridden using the environment variable
PGCLIENTENCODING.
Entering SQL Commands
In normal operation, psql provides a prompt with the name of the
database to which psql is currently connected, followed by the string
=>. For example:
$ psql testdb
psql (15.8)
Type "help" for help.
testdb=>
At the prompt, the user can type in SQL commands. Ordinarily, input
lines are sent to the server when a command-terminating semicolon is
reached. An end of line does not terminate a command. Thus commands can
be spread over several lines for clarity. If the command was sent and
executed without error, the results of the command are displayed on the
screen.
If untrusted users have access to a database that has not adopted a
secure schema usage pattern, begin your session by removing
publicly-writable schemas from search_path. One can add
options=-csearch_path= to the connection string or issue SELECT
pg_catalog.set_config('search_path', '', false) before other SQL
commands. This consideration is not specific to psql; it applies to
every interface for executing arbitrary SQL commands.
Whenever a command is executed, psql also polls for asynchronous
notification events generated by LISTEN and NOTIFY.
While C-style block comments are passed to the server for processing
and removal, SQL-standard comments are removed by psql.
Meta-Commands
Anything you enter in psql that begins with an unquoted backslash is a
psql meta-command that is processed by psql itself. These commands make
psql more useful for administration or scripting. Meta-commands are
often called slash or backslash commands.
The format of a psql command is the backslash, followed immediately by
a command verb, then any arguments. The arguments are separated from
the command verb and each other by any number of whitespace characters.
To include whitespace in an argument you can quote it with single
quotes. To include a single quote in an argument, write two single
quotes within single-quoted text. Anything contained in single quotes
is furthermore subject to C-like substitutions for \n (new line), \t
(tab), \b (backspace), \r (carriage return), \f (form feed), \digits
(octal), and \xdigits (hexadecimal). A backslash preceding any other
character within single-quoted text quotes that single character,
whatever it is.
If an unquoted colon (:) followed by a psql variable name appears
within an argument, it is replaced by the variable's value, as
described in SQL Interpolation below. The forms :'variable_name' and
:"variable_name" described there work as well. The :{?variable_name}
syntax allows testing whether a variable is defined. It is substituted
by TRUE or FALSE. Escaping the colon with a backslash protects it from
substitution.
Within an argument, text that is enclosed in backquotes (`) is taken as
a command line that is passed to the shell. The output of the command
(with any trailing newline removed) replaces the backquoted text.
Within the text enclosed in backquotes, no special quoting or other
processing occurs, except that appearances of :variable_name where
variable_name is a psql variable name are replaced by the variable's
value. Also, appearances of :'variable_name' are replaced by the
variable's value suitably quoted to become a single shell command
argument. (The latter form is almost always preferable, unless you are
very sure of what is in the variable.) Because carriage return and line
feed characters cannot be safely quoted on all platforms, the
:'variable_name' form prints an error message and does not substitute
the variable value when such characters appear in the value.
Some commands take an SQL identifier (such as a table name) as
argument. These arguments follow the syntax rules of SQL: Unquoted
letters are forced to lowercase, while double quotes (") protect
letters from case conversion and allow incorporation of whitespace into
the identifier. Within double quotes, paired double quotes reduce to a
single double quote in the resulting name. For example, FOO"BAR"BAZ is
interpreted as fooBARbaz, and "A weird"" name" becomes A weird" name.
Parsing for arguments stops at the end of the line, or when another
unquoted backslash is found. An unquoted backslash is taken as the
beginning of a new meta-command. The special sequence \\ (two
backslashes) marks the end of arguments and continues parsing SQL
commands, if any. That way SQL and psql commands can be freely mixed on
a line. But in any case, the arguments of a meta-command cannot
continue beyond the end of the line.
Many of the meta-commands act on the current query buffer. This is
simply a buffer holding whatever SQL command text has been typed but
not yet sent to the server for execution. This will include previous
input lines as well as any text appearing before the meta-command on
the same line.
The following meta-commands are defined:
\a
If the current table output format is unaligned, it is switched to
aligned. If it is not unaligned, it is set to unaligned. This
command is kept for backwards compatibility. See \pset for a more
general solution.
\c or \connect [ -reuse-previous=on|off ] [ dbname [ username ] [ host
] [ port ] | conninfo ]
Establishes a new connection to a PostgreSQL server. The connection
parameters to use can be specified either using a positional syntax
(one or more of database name, user, host, and port), or using a
conninfo connection string as detailed in Section 34.1.1. If no
arguments are given, a new connection is made using the same
parameters as before.
Specifying any of dbname, username, host or port as - is equivalent
to omitting that parameter.
The new connection can re-use connection parameters from the
previous connection; not only database name, user, host, and port,
but other settings such as sslmode. By default, parameters are
re-used in the positional syntax, but not when a conninfo string is
given. Passing a first argument of -reuse-previous=on or
-reuse-previous=off overrides that default. If parameters are
re-used, then any parameter not explicitly specified as a
positional parameter or in the conninfo string is taken from the
existing connection's parameters. An exception is that if the host
setting is changed from its previous value using the positional
syntax, any hostaddr setting present in the existing connection's
parameters is dropped. Also, any password used for the existing
connection will be re-used only if the user, host, and port
settings are not changed. When the command neither specifies nor
reuses a particular parameter, the libpq default is used.
If the new connection is successfully made, the previous connection
is closed. If the connection attempt fails (wrong user name, access
denied, etc.), the previous connection will be kept if psql is in
interactive mode. But when executing a non-interactive script, the
old connection is closed and an error is reported. That may or may
not terminate the script; if it does not, all database-accessing
commands will fail until another \connect command is successfully
executed. This distinction was chosen as a user convenience against
typos on the one hand, and a safety mechanism that scripts are not
accidentally acting on the wrong database on the other hand. Note
that whenever a \connect command attempts to re-use parameters, the
values re-used are those of the last successful connection, not of
any failed attempts made subsequently. However, in the case of a
non-interactive \connect failure, no parameters are allowed to be
re-used later, since the script would likely be expecting the
values from the failed \connect to be re-used.
Examples:
=> \c mydb myuser host.dom 6432
=> \c service=foo
=> \c "host=localhost port=5432 dbname=mydb connect_timeout=10 sslmode=disable"
=> \c -reuse-previous=on sslmode=require -- changes only sslmode
=> \c postgresql://tom@localhost/mydb?application_name=myapp
\C [ title ]
Sets the title of any tables being printed as the result of a query
or unset any such title. This command is equivalent to \pset title
title. (The name of this command derives from "caption", as it was
previously only used to set the caption in an HTML table.)
\cd [ directory ]
Changes the current working directory to directory. Without
argument, changes to the current user's home directory.
Tip
To print your current working directory, use \! pwd.
\conninfo
Outputs information about the current database connection.
\copy { table [ ( column_list ) ] } from { 'filename' | program
'command' | stdin | pstdin } [ [ with ] ( option [, ...] ) ] [ where
condition ]
\copy { table [ ( column_list ) ] | ( query ) } to { 'filename' |
program 'command' | stdout | pstdout } [ [ with ] ( option [, ...] ) ]
Performs a frontend (client) copy. This is an operation that runs
an SQL COPY command, but instead of the server reading or writing
the specified file, psql reads or writes the file and routes the
data between the server and the local file system. This means that
file accessibility and privileges are those of the local user, not
the server, and no SQL superuser privileges are required.
When program is specified, command is executed by psql and the data
passed from or to command is routed between the server and the
client. Again, the execution privileges are those of the local
user, not the server, and no SQL superuser privileges are required.
For \copy ... from stdin, data rows are read from the same source
that issued the command, continuing until \. is read or the stream
reaches EOF. This option is useful for populating tables in-line
within an SQL script file. For \copy ... to stdout, output is sent
to the same place as psql command output, and the COPY count
command status is not printed (since it might be confused with a
data row). To read/write psql's standard input or output regardless
of the current command source or \o option, write from pstdin or to
pstdout.
The syntax of this command is similar to that of the SQL COPY
command. All options other than the data source/destination are as
specified for COPY. Because of this, special parsing rules apply to
the \copy meta-command. Unlike most other meta-commands, the entire
remainder of the line is always taken to be the arguments of \copy,
and neither variable interpolation nor backquote expansion are
performed in the arguments.
Tip
Another way to obtain the same result as \copy ... to is to use
the SQL COPY ... TO STDOUT command and terminate it with \g
filename or \g |program. Unlike \copy, this method allows the
command to span multiple lines; also, variable interpolation
and backquote expansion can be used.
Tip
These operations are not as efficient as the SQL COPY command
with a file or program data source or destination, because all
data must pass through the client/server connection. For large
amounts of data the SQL command might be preferable. Also,
because of this pass-through method, \copy ... from in CSV mode
will erroneously treat a \. data value alone on a line as an
end-of-input marker.
\copyright
Shows the copyright and distribution terms of PostgreSQL.
\crosstabview [ colV [ colH [ colD [ sortcolH ] ] ] ]
Executes the current query buffer (like \g) and shows the results
in a crosstab grid. The query must return at least three columns.
The output column identified by colV becomes a vertical header and
the output column identified by colH becomes a horizontal header.
colD identifies the output column to display within the grid.
sortcolH identifies an optional sort column for the horizontal
header.
Each column specification can be a column number (starting at 1) or
a column name. The usual SQL case folding and quoting rules apply
to column names. If omitted, colV is taken as column 1 and colH as
column 2. colH must differ from colV. If colD is not specified,
then there must be exactly three columns in the query result, and
the column that is neither colV nor colH is taken to be colD.
The vertical header, displayed as the leftmost column, contains the
values found in column colV, in the same order as in the query
results, but with duplicates removed.
The horizontal header, displayed as the first row, contains the
values found in column colH, with duplicates removed. By default,
these appear in the same order as in the query results. But if the
optional sortcolH argument is given, it identifies a column whose
values must be integer numbers, and the values from colH will
appear in the horizontal header sorted according to the
corresponding sortcolH values.
Inside the crosstab grid, for each distinct value x of colH and
each distinct value y of colV, the cell located at the intersection
(x,y) contains the value of the colD column in the query result row
for which the value of colH is x and the value of colV is y. If
there is no such row, the cell is empty. If there are multiple such
rows, an error is reported.
\d[S+] [ pattern ]
For each relation (table, view, materialized view, index, sequence,
or foreign table) or composite type matching the pattern, show all
columns, their types, the tablespace (if not the default) and any
special attributes such as NOT NULL or defaults. Associated
indexes, constraints, rules, and triggers are also shown. For
foreign tables, the associated foreign server is shown as well.
("Matching the pattern" is defined in Patterns below.)
For some types of relation, \d shows additional information for
each column: column values for sequences, indexed expressions for
indexes, and foreign data wrapper options for foreign tables.
The command form \d+ is identical, except that more information is
displayed: any comments associated with the columns of the table
are shown, as is the presence of OIDs in the table, the view
definition if the relation is a view, a non-default replica
identity setting and the access method name if the relation has an
access method.
By default, only user-created objects are shown; supply a pattern
or the S modifier to include system objects.
Note
If \d is used without a pattern argument, it is equivalent to
\dtvmsE which will show a list of all visible tables, views,
materialized views, sequences and foreign tables. This is
purely a convenience measure.
\da[S] [ pattern ]
Lists aggregate functions, together with their return type and the
data types they operate on. If pattern is specified, only
aggregates whose names match the pattern are shown. By default,
only user-created objects are shown; supply a pattern or the S
modifier to include system objects.
\dA[+] [ pattern ]
Lists access methods. If pattern is specified, only access methods
whose names match the pattern are shown. If + is appended to the
command name, each access method is listed with its associated
handler function and description.
\dAc[+] [access-method-pattern [input-type-pattern]]
Lists operator classes (see Section 38.16.1). If
access-method-pattern is specified, only operator classes
associated with access methods whose names match that pattern are
listed. If input-type-pattern is specified, only operator classes
associated with input types whose names match that pattern are
listed. If + is appended to the command name, each operator class
is listed with its associated operator family and owner.
\dAf[+] [access-method-pattern [input-type-pattern]]
Lists operator families (see Section 38.16.5). If
access-method-pattern is specified, only operator families
associated with access methods whose names match that pattern are
listed. If input-type-pattern is specified, only operator families
associated with input types whose names match that pattern are
listed. If + is appended to the command name, each operator family
is listed with its owner.
\dAo[+] [access-method-pattern [operator-family-pattern]]
Lists operators associated with operator families (see
Section 38.16.2). If access-method-pattern is specified, only
members of operator families associated with access methods whose
names match that pattern are listed. If operator-family-pattern is
specified, only members of operator families whose names match that
pattern are listed. If + is appended to the command name, each
operator is listed with its sort operator family (if it is an
ordering operator).
\dAp[+] [access-method-pattern [operator-family-pattern]]
Lists support functions associated with operator families (see
Section 38.16.3). If access-method-pattern is specified, only
functions of operator families associated with access methods whose
names match that pattern are listed. If operator-family-pattern is
specified, only functions of operator families whose names match
that pattern are listed. If + is appended to the command name,
functions are displayed verbosely, with their actual parameter
lists.
\db[+] [ pattern ]
Lists tablespaces. If pattern is specified, only tablespaces whose
names match the pattern are shown. If + is appended to the command
name, each tablespace is listed with its associated options,
on-disk size, permissions and description.
\dc[S+] [ pattern ]
Lists conversions between character-set encodings. If pattern is
specified, only conversions whose names match the pattern are
listed. By default, only user-created objects are shown; supply a
pattern or the S modifier to include system objects. If + is
appended to the command name, each object is listed with its
associated description.
\dconfig[+] [ pattern ]
Lists server configuration parameters and their values. If pattern
is specified, only parameters whose names match the pattern are
listed. Without a pattern, only parameters that are set to
non-default values are listed. (Use \dconfig * to see all
parameters.) If + is appended to the command name, each parameter
is listed with its data type, context in which the parameter can be
set, and access privileges (if non-default access privileges have
been granted).
\dC[+] [ pattern ]
Lists type casts. If pattern is specified, only casts whose source
or target types match the pattern are listed. If + is appended to
the command name, each object is listed with its associated
description.
\dd[S] [ pattern ]
Shows the descriptions of objects of type constraint, operator
class, operator family, rule, and trigger. All other comments may
be viewed by the respective backslash commands for those object
types.
\dd displays descriptions for objects matching the pattern, or of
visible objects of the appropriate type if no argument is given.
But in either case, only objects that have a description are
listed. By default, only user-created objects are shown; supply a
pattern or the S modifier to include system objects.
Descriptions for objects can be created with the COMMENT SQL
command.
\dD[S+] [ pattern ]
Lists domains. If pattern is specified, only domains whose names
match the pattern are shown. By default, only user-created objects
are shown; supply a pattern or the S modifier to include system
objects. If + is appended to the command name, each object is
listed with its associated permissions and description.
\ddp [ pattern ]
Lists default access privilege settings. An entry is shown for each
role (and schema, if applicable) for which the default privilege
settings have been changed from the built-in defaults. If pattern
is specified, only entries whose role name or schema name matches
the pattern are listed.
The ALTER DEFAULT PRIVILEGES command is used to set default access
privileges. The meaning of the privilege display is explained in
Section 5.7.
\dE[S+] [ pattern ]
\di[S+] [ pattern ]
\dm[S+] [ pattern ]
\ds[S+] [ pattern ]
\dt[S+] [ pattern ]
\dv[S+] [ pattern ]
In this group of commands, the letters E, i, m, s, t, and v stand
for foreign table, index, materialized view, sequence, table, and
view, respectively. You can specify any or all of these letters, in
any order, to obtain a listing of objects of these types. For
example, \dti lists tables and indexes. If + is appended to the
command name, each object is listed with its persistence status
(permanent, temporary, or unlogged), physical size on disk, and
associated description if any. If pattern is specified, only
objects whose names match the pattern are listed. By default, only
user-created objects are shown; supply a pattern or the S modifier
to include system objects.
\des[+] [ pattern ]
Lists foreign servers (mnemonic: "external servers"). If pattern is
specified, only those servers whose name matches the pattern are
listed. If the form \des+ is used, a full description of each
server is shown, including the server's access privileges, type,
version, options, and description.
\det[+] [ pattern ]
Lists foreign tables (mnemonic: "external tables"). If pattern is
specified, only entries whose table name or schema name matches the
pattern are listed. If the form \det+ is used, generic options and
the foreign table description are also displayed.
\deu[+] [ pattern ]
Lists user mappings (mnemonic: "external users"). If pattern is
specified, only those mappings whose user names match the pattern
are listed. If the form \deu+ is used, additional information about
each mapping is shown.
Caution
\deu+ might also display the user name and password of the
remote user, so care should be taken not to disclose them.
\dew[+] [ pattern ]
Lists foreign-data wrappers (mnemonic: "external wrappers"). If
pattern is specified, only those foreign-data wrappers whose name
matches the pattern are listed. If the form \dew+ is used, the
access privileges, options, and description of the foreign-data
wrapper are also shown.
\df[anptwS+] [ pattern [ arg_pattern ... ] ]
Lists functions, together with their result data types, argument
data types, and function types, which are classified as "agg"
(aggregate), "normal", "procedure", "trigger", or "window". To
display only functions of specific type(s), add the corresponding
letters a, n, p, t, or w to the command. If pattern is specified,
only functions whose names match the pattern are shown. Any
additional arguments are type-name patterns, which are matched to
the type names of the first, second, and so on arguments of the
function. (Matching functions can have more arguments than what you
specify. To prevent that, write a dash - as the last arg_pattern.)
By default, only user-created objects are shown; supply a pattern
or the S modifier to include system objects. If the form \df+ is
used, additional information about each function is shown,
including volatility, parallel safety, owner, security
classification, access privileges, language, source code and
description.
\dF[+] [ pattern ]
Lists text search configurations. If pattern is specified, only
configurations whose names match the pattern are shown. If the form
\dF+ is used, a full description of each configuration is shown,
including the underlying text search parser and the dictionary list
for each parser token type.
\dFd[+] [ pattern ]
Lists text search dictionaries. If pattern is specified, only
dictionaries whose names match the pattern are shown. If the form
\dFd+ is used, additional information is shown about each selected
dictionary, including the underlying text search template and the
option values.
\dFp[+] [ pattern ]
Lists text search parsers. If pattern is specified, only parsers
whose names match the pattern are shown. If the form \dFp+ is used,
a full description of each parser is shown, including the
underlying functions and the list of recognized token types.
\dFt[+] [ pattern ]
Lists text search templates. If pattern is specified, only
templates whose names match the pattern are shown. If the form
\dFt+ is used, additional information is shown about each template,
including the underlying function names.
\dg[S+] [ pattern ]
Lists database roles. (Since the concepts of "users" and "groups"
have been unified into "roles", this command is now equivalent to
\du.) By default, only user-created roles are shown; supply the S
modifier to include system roles. If pattern is specified, only
those roles whose names match the pattern are listed. If the form
\dg+ is used, additional information is shown about each role;
currently this adds the comment for each role.
\dl[+]
This is an alias for \lo_list, which shows a list of large objects.
If + is appended to the command name, each large object is listed
with its associated permissions, if any.
\dL[S+] [ pattern ]
Lists procedural languages. If pattern is specified, only languages
whose names match the pattern are listed. By default, only
user-created languages are shown; supply the S modifier to include
system objects. If + is appended to the command name, each language
is listed with its call handler, validator, access privileges, and
whether it is a system object.
\dn[S+] [ pattern ]
Lists schemas (namespaces). If pattern is specified, only schemas
whose names match the pattern are listed. By default, only
user-created objects are shown; supply a pattern or the S modifier
to include system objects. If + is appended to the command name,
each object is listed with its associated permissions and
description, if any.
\do[S+] [ pattern [ arg_pattern [ arg_pattern ] ] ]
Lists operators with their operand and result types. If pattern is
specified, only operators whose names match the pattern are listed.
If one arg_pattern is specified, only prefix operators whose right
argument's type name matches that pattern are listed. If two
arg_patterns are specified, only binary operators whose argument
type names match those patterns are listed. (Alternatively, write -
for the unused argument of a unary operator.) By default, only
user-created objects are shown; supply a pattern or the S modifier
to include system objects. If + is appended to the command name,
additional information about each operator is shown, currently just
the name of the underlying function.
\dO[S+] [ pattern ]
Lists collations. If pattern is specified, only collations whose
names match the pattern are listed. By default, only user-created
objects are shown; supply a pattern or the S modifier to include
system objects. If + is appended to the command name, each
collation is listed with its associated description, if any. Note
that only collations usable with the current database's encoding
are shown, so the results may vary in different databases of the
same installation.
\dp [ pattern ]
Lists tables, views and sequences with their associated access
privileges. If pattern is specified, only tables, views and
sequences whose names match the pattern are listed.
The GRANT and REVOKE commands are used to set access privileges.
The meaning of the privilege display is explained in Section 5.7.
\dP[itn+] [ pattern ]
Lists partitioned relations. If pattern is specified, only entries
whose name matches the pattern are listed. The modifiers t (tables)
and i (indexes) can be appended to the command, filtering the kind
of relations to list. By default, partitioned tables and indexes
are listed.
If the modifier n ("nested") is used, or a pattern is specified,
then non-root partitioned relations are included, and a column is
shown displaying the parent of each partitioned relation.
If + is appended to the command name, the sum of the sizes of each
relation's partitions is also displayed, along with the relation's
description. If n is combined with +, two sizes are shown: one
including the total size of directly-attached leaf partitions, and
another showing the total size of all partitions, including
indirectly attached sub-partitions.
\drds [ role-pattern [ database-pattern ] ]
Lists defined configuration settings. These settings can be
role-specific, database-specific, or both. role-pattern and
database-pattern are used to select specific roles and databases to
list, respectively. If omitted, or if * is specified, all settings
are listed, including those not role-specific or database-specific,
respectively.
The ALTER ROLE and ALTER DATABASE commands are used to define
per-role and per-database configuration settings.
\dRp[+] [ pattern ]
Lists replication publications. If pattern is specified, only those
publications whose names match the pattern are listed. If + is
appended to the command name, the tables and schemas associated
with each publication are shown as well.
\dRs[+] [ pattern ]
Lists replication subscriptions. If pattern is specified, only
those subscriptions whose names match the pattern are listed. If +
is appended to the command name, additional properties of the
subscriptions are shown.
\dT[S+] [ pattern ]
Lists data types. If pattern is specified, only types whose names
match the pattern are listed. If + is appended to the command name,
each type is listed with its internal name and size, its allowed
values if it is an enum type, and its associated permissions. By
default, only user-created objects are shown; supply a pattern or
the S modifier to include system objects.
\du[S+] [ pattern ]
Lists database roles. (Since the concepts of "users" and "groups"
have been unified into "roles", this command is now equivalent to
\dg.) By default, only user-created roles are shown; supply the S
modifier to include system roles. If pattern is specified, only
those roles whose names match the pattern are listed. If the form
\du+ is used, additional information is shown about each role;
currently this adds the comment for each role.
\dx[+] [ pattern ]
Lists installed extensions. If pattern is specified, only those
extensions whose names match the pattern are listed. If the form
\dx+ is used, all the objects belonging to each matching extension
are listed.
\dX [ pattern ]
Lists extended statistics. If pattern is specified, only those
extended statistics whose names match the pattern are listed.
The status of each kind of extended statistics is shown in a column
named after its statistic kind (e.g. Ndistinct). defined means
that it was requested when creating the statistics, and NULL means
it wasn't requested. You can use pg_stats_ext if you'd like to know
whether ANALYZE was run and statistics are available to the
planner.
\dy[+] [ pattern ]
Lists event triggers. If pattern is specified, only those event
triggers whose names match the pattern are listed. If + is appended
to the command name, each object is listed with its associated
description.
\e or \edit [ filename ] [ line_number ]
If filename is specified, the file is edited; after the editor
exits, the file's content is copied into the current query buffer.
If no filename is given, the current query buffer is copied to a
temporary file which is then edited in the same fashion. Or, if the
current query buffer is empty, the most recently executed query is
copied to a temporary file and edited in the same fashion.
If you edit a file or the previous query, and you quit the editor
without modifying the file, the query buffer is cleared. Otherwise,
the new contents of the query buffer are re-parsed according to the
normal rules of psql, treating the whole buffer as a single line.
Any complete queries are immediately executed; that is, if the
query buffer contains or ends with a semicolon, everything up to
that point is executed and removed from the query buffer. Whatever
remains in the query buffer is redisplayed. Type semicolon or \g to
send it, or \r to cancel it by clearing the query buffer.
Treating the buffer as a single line primarily affects
meta-commands: whatever is in the buffer after a meta-command will
be taken as argument(s) to the meta-command, even if it spans
multiple lines. (Thus you cannot make meta-command-using scripts
this way. Use \i for that.)
If a line number is specified, psql will position the cursor on the
specified line of the file or query buffer. Note that if a single
all-digits argument is given, psql assumes it is a line number, not
a file name.
Tip
See Environment, below, for how to configure and customize your
editor.
\echo text [ ... ]
Prints the evaluated arguments to standard output, separated by
spaces and followed by a newline. This can be useful to intersperse
information in the output of scripts. For example:
=> \echo `date`
Tue Oct 26 21:40:57 CEST 1999
If the first argument is an unquoted -n the trailing newline is not
written (nor is the first argument).
Tip
If you use the \o command to redirect your query output you
might wish to use \qecho instead of this command. See also
\warn.
\ef [ function_description [ line_number ] ]
This command fetches and edits the definition of the named function
or procedure, in the form of a CREATE OR REPLACE FUNCTION or CREATE
OR REPLACE PROCEDURE command. Editing is done in the same way as
for \edit. If you quit the editor without saving, the statement is
discarded. If you save and exit the editor, the updated command is
executed immediately if you added a semicolon to it. Otherwise it
is redisplayed; type semicolon or \g to send it, or \r to cancel.
The target function can be specified by name alone, or by name and
arguments, for example foo(integer, text). The argument types must
be given if there is more than one function of the same name.
If no function is specified, a blank CREATE FUNCTION template is
presented for editing.
If a line number is specified, psql will position the cursor on the
specified line of the function body. (Note that the function body
typically does not begin on the first line of the file.)
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \ef, and neither variable
interpolation nor backquote expansion are performed in the
arguments.
Tip
See Environment, below, for how to configure and customize your
editor.
\encoding [ encoding ]
Sets the client character set encoding. Without an argument, this
command shows the current encoding.
\errverbose
Repeats the most recent server error message at maximum verbosity,
as though VERBOSITY were set to verbose and SHOW_CONTEXT were set
to always.
\ev [ view_name [ line_number ] ]
This command fetches and edits the definition of the named view, in
the form of a CREATE OR REPLACE VIEW command. Editing is done in
the same way as for \edit. If you quit the editor without saving,
the statement is discarded. If you save and exit the editor, the
updated command is executed immediately if you added a semicolon to
it. Otherwise it is redisplayed; type semicolon or \g to send it,
or \r to cancel.
If no view is specified, a blank CREATE VIEW template is presented
for editing.
If a line number is specified, psql will position the cursor on the
specified line of the view definition.
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \ev, and neither variable
interpolation nor backquote expansion are performed in the
arguments.
\f [ string ]
Sets the field separator for unaligned query output. The default is
the vertical bar (|). It is equivalent to \pset fieldsep.
\g [ (option=value [...]) ] [ filename ]
\g [ (option=value [...]) ] [ |command ]
Sends the current query buffer to the server for execution.
If parentheses appear after \g, they surround a space-separated
list of option=value formatting-option clauses, which are
interpreted in the same way as \pset option value commands, but
take effect only for the duration of this query. In this list,
spaces are not allowed around = signs, but are required between
option clauses. If =value is omitted, the named option is changed
in the same way as for \pset option with no explicit value.
If a filename or |command argument is given, the query's output is
written to the named file or piped to the given shell command,
instead of displaying it as usual. The file or command is written
to only if the query successfully returns zero or more tuples, not
if the query fails or is a non-data-returning SQL command.
If the current query buffer is empty, the most recently sent query
is re-executed instead. Except for that behavior, \g without any
arguments is essentially equivalent to a semicolon. With arguments,
\g provides a "one-shot" alternative to the \o command, and
additionally allows one-shot adjustments of the output formatting
options normally set by \pset.
When the last argument begins with |, the entire remainder of the
line is taken to be the command to execute, and neither variable
interpolation nor backquote expansion are performed in it. The rest
of the line is simply passed literally to the shell.
\gdesc
Shows the description (that is, the column names and data types) of
the result of the current query buffer. The query is not actually
executed; however, if it contains some type of syntax error, that
error will be reported in the normal way.
If the current query buffer is empty, the most recently sent query
is described instead.
\getenv psql_var env_var
Gets the value of the environment variable env_var and assigns it
to the psql variable psql_var. If env_var is not defined in the
psql process's environment, psql_var is not changed. Example:
=> \getenv home HOME
=> \echo :home
/home/postgres
\gexec
Sends the current query buffer to the server, then treats each
column of each row of the query's output (if any) as an SQL
statement to be executed. For example, to create an index on each
column of my_table:
=> SELECT format('create index on my_table(%I)', attname)
-> FROM pg_attribute
-> WHERE attrelid = 'my_table'::regclass AND attnum > 0
-> ORDER BY attnum
-> \gexec
CREATE INDEX
CREATE INDEX
CREATE INDEX
CREATE INDEX
The generated queries are executed in the order in which the rows
are returned, and left-to-right within each row if there is more
than one column. NULL fields are ignored. The generated queries are
sent literally to the server for processing, so they cannot be psql
meta-commands nor contain psql variable references. If any
individual query fails, execution of the remaining queries
continues unless ON_ERROR_STOP is set. Execution of each query is
subject to ECHO processing. (Setting ECHO to all or queries is
often advisable when using \gexec.) Query logging, single-step
mode, timing, and other query execution features apply to each
generated query as well.
If the current query buffer is empty, the most recently sent query
is re-executed instead.
\gset [ prefix ]
Sends the current query buffer to the server and stores the query's
output into psql variables (see Variables below). The query to be
executed must return exactly one row. Each column of the row is
stored into a separate variable, named the same as the column. For
example:
=> SELECT 'hello' AS var1, 10 AS var2
-> \gset
=> \echo :var1 :var2
hello 10
If you specify a prefix, that string is prepended to the query's
column names to create the variable names to use:
=> SELECT 'hello' AS var1, 10 AS var2
-> \gset result_
=> \echo :result_var1 :result_var2
hello 10
If a column result is NULL, the corresponding variable is unset
rather than being set.
If the query fails or does not return one row, no variables are
changed.
If the current query buffer is empty, the most recently sent query
is re-executed instead.
\gx [ (option=value [...]) ] [ filename ]
\gx [ (option=value [...]) ] [ |command ]
\gx is equivalent to \g, except that it forces expanded output mode
for this query, as if expanded=on were included in the list of
\pset options. See also \x.
\h or \help [ command ]
Gives syntax help on the specified SQL command. If command is not
specified, then psql will list all the commands for which syntax
help is available. If command is an asterisk (*), then syntax help
on all SQL commands is shown.
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \help, and neither
variable interpolation nor backquote expansion are performed in the
arguments.
Note
To simplify typing, commands that consists of several words do
not have to be quoted. Thus it is fine to type \help alter
table.
\H or \html
Turns on HTML query output format. If the HTML format is already
on, it is switched back to the default aligned text format. This
command is for compatibility and convenience, but see \pset about
setting other output options.
\i or \include filename
Reads input from the file filename and executes it as though it had
been typed on the keyboard.
If filename is - (hyphen), then standard input is read until an EOF
indication or \q meta-command. This can be used to intersperse
interactive input with input from files. Note that Readline
behavior will be used only if it is active at the outermost level.
Note
If you want to see the lines on the screen as they are read you
must set the variable ECHO to all.
\if expression
\elif expression
\else
\endif
This group of commands implements nestable conditional blocks. A
conditional block must begin with an \if and end with an \endif. In
between there may be any number of \elif clauses, which may
optionally be followed by a single \else clause. Ordinary queries
and other types of backslash commands may (and usually do) appear
between the commands forming a conditional block.
The \if and \elif commands read their argument(s) and evaluate them
as a Boolean expression. If the expression yields true then
processing continues normally; otherwise, lines are skipped until a
matching \elif, \else, or \endif is reached. Once an \if or \elif
test has succeeded, the arguments of later \elif commands in the
same block are not evaluated but are treated as false. Lines
following an \else are processed only if no earlier matching \if or
\elif succeeded.
The expression argument of an \if or \elif command is subject to
variable interpolation and backquote expansion, just like any other
backslash command argument. After that it is evaluated like the
value of an on/off option variable. So a valid value is any
unambiguous case-insensitive match for one of: true, false, 1, 0,
on, off, yes, no. For example, t, T, and tR will all be considered
to be true.
Expressions that do not properly evaluate to true or false will
generate a warning and be treated as false.
Lines being skipped are parsed normally to identify queries and
backslash commands, but queries are not sent to the server, and
backslash commands other than conditionals (\if, \elif, \else,
\endif) are ignored. Conditional commands are checked only for
valid nesting. Variable references in skipped lines are not
expanded, and backquote expansion is not performed either.
All the backslash commands of a given conditional block must appear
in the same source file. If EOF is reached on the main input file
or an \include-ed file before all local \if-blocks have been
closed, then psql will raise an error.
Here is an example:
-- check for the existence of two separate records in the database and store
-- the results in separate psql variables
SELECT
EXISTS(SELECT 1 FROM customer WHERE customer_id = 123) as is_customer,
EXISTS(SELECT 1 FROM employee WHERE employee_id = 456) as is_employee
\gset
\if :is_customer
SELECT * FROM customer WHERE customer_id = 123;
\elif :is_employee
\echo 'is not a customer but is an employee'
SELECT * FROM employee WHERE employee_id = 456;
\else
\if yes
\echo 'not a customer or employee'
\else
\echo 'this will never print'
\endif
\endif
\ir or \include_relative filename
The \ir command is similar to \i, but resolves relative file names
differently. When executing in interactive mode, the two commands
behave identically. However, when invoked from a script, \ir
interprets file names relative to the directory in which the script
is located, rather than the current working directory.
\l[+] or \list[+] [ pattern ]
List the databases in the server and show their names, owners,
character set encodings, and access privileges. If pattern is
specified, only databases whose names match the pattern are listed.
If + is appended to the command name, database sizes, default
tablespaces, and descriptions are also displayed. (Size information
is only available for databases that the current user can connect
to.)
\lo_export loid filename
Reads the large object with OID loid from the database and writes
it to filename. Note that this is subtly different from the server
function lo_export, which acts with the permissions of the user
that the database server runs as and on the server's file system.
Tip
Use \lo_list to find out the large object's OID.
\lo_import filename [ comment ]
Stores the file into a PostgreSQL large object. Optionally, it
associates the given comment with the object. Example:
foo=> \lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'
lo_import 152801
The response indicates that the large object received object ID
152801, which can be used to access the newly-created large object
in the future. For the sake of readability, it is recommended to
always associate a human-readable comment with every object. Both
OIDs and comments can be viewed with the \lo_list command.
Note that this command is subtly different from the server-side
lo_import because it acts as the local user on the local file
system, rather than the server's user and file system.
\lo_list[+]
Shows a list of all PostgreSQL large objects currently stored in
the database, along with any comments provided for them. If + is
appended to the command name, each large object is listed with its
associated permissions, if any.
\lo_unlink loid
Deletes the large object with OID loid from the database.
Tip
Use \lo_list to find out the large object's OID.
\o or \out [ filename ]
\o or \out [ |command ]
Arranges to save future query results to the file filename or pipe
future results to the shell command command. If no argument is
specified, the query output is reset to the standard output.
If the argument begins with |, then the entire remainder of the
line is taken to be the command to execute, and neither variable
interpolation nor backquote expansion are performed in it. The rest
of the line is simply passed literally to the shell.
"Query results" includes all tables, command responses, and notices
obtained from the database server, as well as output of various
backslash commands that query the database (such as \d); but not
error messages.
Tip
To intersperse text output in between query results, use
\qecho.
\p or \print
Print the current query buffer to the standard output. If the
current query buffer is empty, the most recently executed query is
printed instead.
\password [ username ]
Changes the password of the specified user (by default, the current
user). This command prompts for the new password, encrypts it, and
sends it to the server as an ALTER ROLE command. This makes sure
that the new password does not appear in cleartext in the command
history, the server log, or elsewhere.
\prompt [ text ] name
Prompts the user to supply text, which is assigned to the variable
name. An optional prompt string, text, can be specified. (For
multiword prompts, surround the text with single quotes.)
By default, \prompt uses the terminal for input and output.
However, if the -f command line switch was used, \prompt uses
standard input and standard output.
\pset [ option [ value ] ]
This command sets options affecting the output of query result
tables. option indicates which option is to be set. The semantics
of value vary depending on the selected option. For some options,
omitting value causes the option to be toggled or unset, as
described under the particular option. If no such behavior is
mentioned, then omitting value just results in the current setting
being displayed.
\pset without any arguments displays the current status of all
printing options.
Adjustable printing options are:
border
The value must be a number. In general, the higher the number
the more borders and lines the tables will have, but details
depend on the particular format. In HTML format, this will
translate directly into the border=... attribute. In most
other formats only values 0 (no border), 1 (internal dividing
lines), and 2 (table frame) make sense, and values above 2 will
be treated the same as border = 2. The latex and
latex-longtable formats additionally allow a value of 3 to add
dividing lines between data rows.
columns
Sets the target width for the wrapped format, and also the
width limit for determining whether output is wide enough to
require the pager or switch to the vertical display in expanded
auto mode. Zero (the default) causes the target width to be
controlled by the environment variable COLUMNS, or the detected
screen width if COLUMNS is not set. In addition, if columns is
zero then the wrapped format only affects screen output. If
columns is nonzero then file and pipe output is wrapped to that
width as well.
csv_fieldsep
Specifies the field separator to be used in CSV output format.
If the separator character appears in a field's value, that
field is output within double quotes, following standard CSV
rules. The default is a comma.
expanded (or x)
If value is specified it must be either on or off, which will
enable or disable expanded mode, or auto. If value is omitted
the command toggles between the on and off settings. When
expanded mode is enabled, query results are displayed in two
columns, with the column name on the left and the data on the
right. This mode is useful if the data wouldn't fit on the
screen in the normal "horizontal" mode. In the auto setting,
the expanded mode is used whenever the query output has more
than one column and is wider than the screen; otherwise, the
regular mode is used. The auto setting is only effective in the
aligned and wrapped formats. In other formats, it always
behaves as if the expanded mode is off.
fieldsep
Specifies the field separator to be used in unaligned output
format. That way one can create, for example, tab-separated
output, which other programs might prefer. To set a tab as
field separator, type \pset fieldsep '\t'. The default field
separator is '|' (a vertical bar).
fieldsep_zero
Sets the field separator to use in unaligned output format to a
zero byte.
footer
If value is specified it must be either on or off which will
enable or disable display of the table footer (the (n rows)
count). If value is omitted the command toggles footer display
on or off.
format
Sets the output format to one of aligned, asciidoc, csv, html,
latex, latex-longtable, troff-ms, unaligned, or wrapped. Unique
abbreviations are allowed.
aligned format is the standard, human-readable, nicely
formatted text output; this is the default.
unaligned format writes all columns of a row on one line,
separated by the currently active field separator. This is
useful for creating output that might be intended to be read in
by other programs, for example, tab-separated or
comma-separated format. However, the field separator character
is not treated specially if it appears in a column's value; so
CSV format may be better suited for such purposes.
csv format
writes column values separated by commas, applying the quoting
rules described in RFC 4180. This output is compatible with the
CSV format of the server's COPY command. A header line with
column names is generated unless the tuples_only parameter is
on. Titles and footers are not printed. Each row is terminated
by the system-dependent end-of-line character, which is
typically a single newline (\n) for Unix-like systems or a
carriage return and newline sequence (\r\n) for Microsoft
Windows. Field separator characters other than comma can be
selected with \pset csv_fieldsep.
wrapped format is like aligned but wraps wide data values
across lines to make the output fit in the target column width.
The target width is determined as described under the columns
option. Note that psql will not attempt to wrap column header
titles; therefore, wrapped format behaves the same as aligned
if the total width needed for column headers exceeds the
target.
The asciidoc, html, latex, latex-longtable, and troff-ms
formats put out tables that are intended to be included in
documents using the respective mark-up language. They are not
complete documents! This might not be necessary in HTML, but in
LaTeX you must have a complete document wrapper. The latex
format uses LaTeX's tabular environment. The latex-longtable
format requires the LaTeX longtable and booktabs packages.
linestyle
Sets the border line drawing style to one of ascii, old-ascii,
or unicode. Unique abbreviations are allowed. (That would mean
one letter is enough.) The default setting is ascii. This
option only affects the aligned and wrapped output formats.
ascii style uses plain ASCII characters. Newlines in data are
shown using a + symbol in the right-hand margin. When the
wrapped format wraps data from one line to the next without a
newline character, a dot (.) is shown in the right-hand margin
of the first line, and again in the left-hand margin of the
following line.
old-ascii style uses plain ASCII characters, using the
formatting style used in PostgreSQL 8.4 and earlier. Newlines
in data are shown using a : symbol in place of the left-hand
column separator. When the data is wrapped from one line to the
next without a newline character, a ; symbol is used in place
of the left-hand column separator.
unicode style uses Unicode box-drawing characters. Newlines in
data are shown using a carriage return symbol in the right-hand
margin. When the data is wrapped from one line to the next
without a newline character, an ellipsis symbol is shown in the
right-hand margin of the first line, and again in the left-hand
margin of the following line.
When the border setting is greater than zero, the linestyle
option also determines the characters with which the border
lines are drawn. Plain ASCII characters work everywhere, but
Unicode characters look nicer on displays that recognize them.
null
Sets the string to be printed in place of a null value. The
default is to print nothing, which can easily be mistaken for
an empty string. For example, one might prefer \pset null
'(null)'.
numericlocale
If value is specified it must be either on or off which will
enable or disable display of a locale-specific character to
separate groups of digits to the left of the decimal marker. If
value is omitted the command toggles between regular and
locale-specific numeric output.
pager
Controls use of a pager program for query and psql help output.
When the pager option is off, the pager program is not used.
When the pager option is on, the pager is used when
appropriate, i.e., when the output is to a terminal and will
not fit on the screen. The pager option can also be set to
always, which causes the pager to be used for all terminal
output regardless of whether it fits on the screen. \pset
pager without a value toggles pager use on and off.
If the environment variable PSQL_PAGER or PAGER is set, output
to be paged is piped to the specified program. Otherwise a
platform-dependent default program (such as more) is used.
When using the \watch command to execute a query repeatedly,
the environment variable PSQL_WATCH_PAGER is used to find the
pager program instead, on Unix systems. This is configured
separately because it may confuse traditional pagers, but can
be used to send output to tools that understand psql's output
format (such as pspg --stream).
pager_min_lines
If pager_min_lines is set to a number greater than the page
height, the pager program will not be called unless there are
at least this many lines of output to show. The default setting
is 0.
recordsep
Specifies the record (line) separator to use in unaligned
output format. The default is a newline character.
recordsep_zero
Sets the record separator to use in unaligned output format to
a zero byte.
tableattr (or T)
In HTML format, this specifies attributes to be placed inside
the table tag. This could for example be cellpadding or
bgcolor. Note that you probably don't want to specify border
here, as that is already taken care of by \pset border. If no
value is given, the table attributes are unset.
In latex-longtable format, this controls the proportional width
of each column containing a left-aligned data type. It is
specified as a whitespace-separated list of values, e.g., '0.2
0.2 0.6'. Unspecified output columns use the last specified
value.
title (or C)
Sets the table title for any subsequently printed tables. This
can be used to give your output descriptive tags. If no value
is given, the title is unset.
tuples_only (or t)
If value is specified it must be either on or off which will
enable or disable tuples-only mode. If value is omitted the
command toggles between regular and tuples-only output. Regular
output includes extra information such as column headers,
titles, and various footers. In tuples-only mode, only actual
table data is shown.
unicode_border_linestyle
Sets the border drawing style for the unicode line style to one
of single or double.
unicode_column_linestyle
Sets the column drawing style for the unicode line style to one
of single or double.
unicode_header_linestyle
Sets the header drawing style for the unicode line style to one
of single or double.
Illustrations of how these different formats look can be seen in
Examples, below.
Tip
There are various shortcut commands for \pset. See \a, \C, \f,
\H, \t, \T, and \x.
\q or \quit
Quits the psql program. In a script file, only execution of that
script is terminated.
\qecho text [ ... ]
This command is identical to \echo except that the output will be
written to the query output channel, as set by \o.
\r or \reset
Resets (clears) the query buffer.
\s [ filename ]
Print psql's command line history to filename. If filename is
omitted, the history is written to the standard output (using the
pager if appropriate). This command is not available if psql was
built without Readline support.
\set [ name [ value [ ... ] ] ]
Sets the psql variable name to value, or if more than one value is
given, to the concatenation of all of them. If only one argument is
given, the variable is set to an empty-string value. To unset a
variable, use the \unset command.
\set without any arguments displays the names and values of all
currently-set psql variables.
Valid variable names can contain letters, digits, and underscores.
See Variables below for details. Variable names are case-sensitive.
Certain variables are special, in that they control psql's behavior
or are automatically set to reflect connection state. These
variables are documented in Variables, below.
Note
This command is unrelated to the SQL command SET.
\setenv name [ value ]
Sets the environment variable name to value, or if the value is not
supplied, unsets the environment variable. Example:
testdb=> \setenv PAGER less
testdb=> \setenv LESS -imx4F
\sf[+] function_description
This command fetches and shows the definition of the named function
or procedure, in the form of a CREATE OR REPLACE FUNCTION or CREATE
OR REPLACE PROCEDURE command. The definition is printed to the
current query output channel, as set by \o.
The target function can be specified by name alone, or by name and
arguments, for example foo(integer, text). The argument types must
be given if there is more than one function of the same name.
If + is appended to the command name, then the output lines are
numbered, with the first line of the function body being line 1.
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \sf, and neither variable
interpolation nor backquote expansion are performed in the
arguments.
\sv[+] view_name
This command fetches and shows the definition of the named view, in
the form of a CREATE OR REPLACE VIEW command. The definition is
printed to the current query output channel, as set by \o.
If + is appended to the command name, then the output lines are
numbered from 1.
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \sv, and neither variable
interpolation nor backquote expansion are performed in the
arguments.
\t
Toggles the display of output column name headings and row count
footer. This command is equivalent to \pset tuples_only and is
provided for convenience.
\T table_options
Specifies attributes to be placed within the table tag in HTML
output format. This command is equivalent to \pset tableattr
table_options.
\timing [ on | off ]
With a parameter, turns displaying of how long each SQL statement
takes on or off. Without a parameter, toggles the display between
on and off. The display is in milliseconds; intervals longer than 1
second are also shown in minutes:seconds format, with hours and
days fields added if needed.
\unset name
Unsets (deletes) the psql variable name.
Most variables that control psql's behavior cannot be unset;
instead, an \unset command is interpreted as setting them to their
default values. See Variables below.
\w or \write filename
\w or \write |command
Writes the current query buffer to the file filename or pipes it to
the shell command command. If the current query buffer is empty,
the most recently executed query is written instead.
If the argument begins with |, then the entire remainder of the
line is taken to be the command to execute, and neither variable
interpolation nor backquote expansion are performed in it. The rest
of the line is simply passed literally to the shell.
\warn text [ ... ]
This command is identical to \echo except that the output will be
written to psql's standard error channel, rather than standard
output.
\watch [ seconds ]
Repeatedly execute the current query buffer (as \g does) until
interrupted or the query fails. Wait the specified number of
seconds (default 2) between executions. Each query result is
displayed with a header that includes the \pset title string (if
any), the time as of query start, and the delay interval.
If the current query buffer is empty, the most recently sent query
is re-executed instead.
\x [ on | off | auto ]
Sets or toggles expanded table formatting mode. As such it is
equivalent to \pset expanded.
\z [ pattern ]
Lists tables, views and sequences with their associated access
privileges. If a pattern is specified, only tables, views and
sequences whose names match the pattern are listed.
This is an alias for \dp ("display privileges").
\! [ command ]
With no argument, escapes to a sub-shell; psql resumes when the
sub-shell exits. With an argument, executes the shell command
command.
Unlike most other meta-commands, the entire remainder of the line
is always taken to be the argument(s) of \!, and neither variable
interpolation nor backquote expansion are performed in the
arguments. The rest of the line is simply passed literally to the
shell.
\? [ topic ]
Shows help information. The optional topic parameter (defaulting to
commands) selects which part of psql is explained: commands
describes psql's backslash commands; options describes the
command-line options that can be passed to psql; and variables
shows help about psql configuration variables.
\;
Backslash-semicolon is not a meta-command in the same way as the
preceding commands; rather, it simply causes a semicolon to be
added to the query buffer without any further processing.
Normally, psql will dispatch an SQL command to the server as soon
as it reaches the command-ending semicolon, even if more input
remains on the current line. Thus for example entering
select 1; select 2; select 3;
will result in the three SQL commands being individually sent to
the server, with each one's results being displayed before
continuing to the next command. However, a semicolon entered as \;
will not trigger command processing, so that the command before it
and the one after are effectively combined and sent to the server
in one request. So for example
select 1\; select 2\; select 3;
results in sending the three SQL commands to the server in a single
request, when the non-backslashed semicolon is reached. The server
executes such a request as a single transaction, unless there are
explicit BEGIN/COMMIT commands included in the string to divide it
into multiple transactions. (See Section 55.2.2.1 for more details
about how the server handles multi-query strings.)
Patterns
The various \d commands accept a pattern parameter to specify the
object name(s) to be displayed. In the simplest case, a pattern is
just the exact name of the object. The characters within a pattern
are normally folded to lower case, just as in SQL names; for
example, \dt FOO will display the table named foo. As in SQL names,
placing double quotes around a pattern stops folding to lower case.
Should you need to include an actual double quote character in a
pattern, write it as a pair of double quotes within a double-quote
sequence; again this is in accord with the rules for SQL quoted
identifiers. For example, \dt "FOO""BAR" will display the table
named FOO"BAR (not foo"bar). Unlike the normal rules for SQL names,
you can put double quotes around just part of a pattern, for
instance \dt FOO"FOO"BAR will display the table named fooFOObar.
Whenever the pattern parameter is omitted completely, the \d
commands display all objects that are visible in the current schema
search path -- this is equivalent to using * as the pattern. (An
object is said to be visible if its containing schema is in the
search path and no object of the same kind and name appears earlier
in the search path. This is equivalent to the statement that the
object can be referenced by name without explicit schema
qualification.) To see all objects in the database regardless of
visibility, use *.* as the pattern.
Within a pattern, * matches any sequence of characters (including
no characters) and ? matches any single character. (This notation
is comparable to Unix shell file name patterns.) For example, \dt
int* displays tables whose names begin with int. But within double
quotes, * and ? lose these special meanings and are just matched
literally.
A relation pattern that contains a dot (.) is interpreted as a
schema name pattern followed by an object name pattern. For
example, \dt foo*.*bar* displays all tables whose table name
includes bar that are in schemas whose schema name starts with foo.
When no dot appears, then the pattern matches only objects that are
visible in the current schema search path. Again, a dot within
double quotes loses its special meaning and is matched literally. A
relation pattern that contains two dots (.) is interpreted as a
database name followed by a schema name pattern followed by an
object name pattern. The database name portion will not be treated
as a pattern and must match the name of the currently connected
database, else an error will be raised.
A schema pattern that contains a dot (.) is interpreted as a
database name followed by a schema name pattern. For example, \dn
mydb.*foo* displays all schemas whose schema name includes foo. The
database name portion will not be treated as a pattern and must
match the name of the currently connected database, else an error
will be raised.
Advanced users can use regular-expression notations such as
character classes, for example [0-9] to match any digit. All
regular expression special characters work as specified in
Section 9.7.3, except for . which is taken as a separator as
mentioned above, * which is translated to the regular-expression
notation .*, ? which is translated to ., and $ which is matched
literally. You can emulate these pattern characters at need by
writing ? for ., (R+|) for R*, or (R|) for R?. $ is not needed as
a regular-expression character since the pattern must match the
whole name, unlike the usual interpretation of regular expressions
(in other words, $ is automatically appended to your pattern).
Write * at the beginning and/or end if you don't wish the pattern
to be anchored. Note that within double quotes, all regular
expression special characters lose their special meanings and are
matched literally. Also, the regular expression special characters
are matched literally in operator name patterns (i.e., the argument
of \do).
Advanced Features
Variables
psql provides variable substitution features similar to common Unix
command shells. Variables are simply name/value pairs, where the
value can be any string of any length. The name must consist of
letters (including non-Latin letters), digits, and underscores.
To set a variable, use the psql meta-command \set. For example,
testdb=> \set foo bar
sets the variable foo to the value bar. To retrieve the content of
the variable, precede the name with a colon, for example:
testdb=> \echo :foo
bar
This works in both regular SQL commands and meta-commands; there is
more detail in SQL Interpolation, below.
If you call \set without a second argument, the variable is set to
an empty-string value. To unset (i.e., delete) a variable, use the
command \unset. To show the values of all variables, call \set
without any argument.
Note
The arguments of \set are subject to the same substitution
rules as with other commands. Thus you can construct
interesting references such as \set :foo 'something' and get
"soft links" or "variable variables" of Perl or PHP fame,
respectively. Unfortunately (or fortunately?), there is no way
to do anything useful with these constructs. On the other hand,
\set bar :foo is a perfectly valid way to copy a variable.
A number of these variables are treated specially by psql. They
represent certain option settings that can be changed at run time
by altering the value of the variable, or in some cases represent
changeable state of psql. By convention, all specially treated
variables' names consist of all upper-case ASCII letters (and
possibly digits and underscores). To ensure maximum compatibility
in the future, avoid using such variable names for your own
purposes.
Variables that control psql's behavior generally cannot be unset or
set to invalid values. An \unset command is allowed but is
interpreted as setting the variable to its default value. A \set
command without a second argument is interpreted as setting the
variable to on, for control variables that accept that value, and
is rejected for others. Also, control variables that accept the
values on and off will also accept other common spellings of
Boolean values, such as true and false.
The specially treated variables are:
AUTOCOMMIT
When on (the default), each SQL command is automatically
committed upon successful completion. To postpone commit in
this mode, you must enter a BEGIN or START TRANSACTION SQL
command. When off or unset, SQL commands are not committed
until you explicitly issue COMMIT or END. The autocommit-off
mode works by issuing an implicit BEGIN for you, just before
any command that is not already in a transaction block and is
not itself a BEGIN or other transaction-control command, nor a
command that cannot be executed inside a transaction block
(such as VACUUM).
Note
In autocommit-off mode, you must explicitly abandon any
failed transaction by entering ABORT or ROLLBACK. Also keep
in mind that if you exit the session without committing,
your work will be lost.
Note
The autocommit-on mode is PostgreSQL's traditional
behavior, but autocommit-off is closer to the SQL spec. If
you prefer autocommit-off, you might wish to set it in the
system-wide psqlrc file or your ~/.psqlrc file.
COMP_KEYWORD_CASE
Determines which letter case to use when completing an SQL key
word. If set to lower or upper, the completed word will be in
lower or upper case, respectively. If set to preserve-lower or
preserve-upper (the default), the completed word will be in the
case of the word already entered, but words being completed
without anything entered will be in lower or upper case,
respectively.
DBNAME
The name of the database you are currently connected to. This
is set every time you connect to a database (including program
start-up), but can be changed or unset.
ECHO
If set to all, all nonempty input lines are printed to standard
output as they are read. (This does not apply to lines read
interactively.) To select this behavior on program start-up,
use the switch -a. If set to queries, psql prints each query to
standard output as it is sent to the server. The switch to
select this behavior is -e. If set to errors, then only failed
queries are displayed on standard error output. The switch for
this behavior is -b. If set to none (the default), then no
queries are displayed.
ECHO_HIDDEN
When this variable is set to on and a backslash command queries
the database, the query is first shown. This feature helps you
to study PostgreSQL internals and provide similar functionality
in your own programs. (To select this behavior on program
start-up, use the switch -E.) If you set this variable to the
value noexec, the queries are just shown but are not actually
sent to the server and executed. The default value is off.
ENCODING
The current client character set encoding. This is set every
time you connect to a database (including program start-up),
and when you change the encoding with \encoding, but it can be
changed or unset.
ERROR
true if the last SQL query failed, false if it succeeded. See
also SQLSTATE.
FETCH_COUNT
If this variable is set to an integer value greater than zero,
the results of SELECT queries are fetched and displayed in
groups of that many rows, rather than the default behavior of
collecting the entire result set before display. Therefore only
a limited amount of memory is used, regardless of the size of
the result set. Settings of 100 to 1000 are commonly used when
enabling this feature. Keep in mind that when using this
feature, a query might fail after having already displayed some
rows.
Tip
Although you can use any output format with this feature,
the default aligned format tends to look bad because each
group of FETCH_COUNT rows will be formatted separately,
leading to varying column widths across the row groups. The
other output formats work better.
HIDE_TABLEAM
If this variable is set to true, a table's access method
details are not displayed. This is mainly useful for regression
tests.
HIDE_TOAST_COMPRESSION
If this variable is set to true, column compression method
details are not displayed. This is mainly useful for regression
tests.
HISTCONTROL
If this variable is set to ignorespace, lines which begin with
a space are not entered into the history list. If set to a
value of ignoredups, lines matching the previous history line
are not entered. A value of ignoreboth combines the two
options. If set to none (the default), all lines read in
interactive mode are saved on the history list.
Note
This feature was shamelessly plagiarized from Bash.
HISTFILE
The file name that will be used to store the history list. If
unset, the file name is taken from the PSQL_HISTORY environment
variable. If that is not set either, the default is
~/.psql_history, or %APPDATA%\postgresql\psql_history on
Windows. For example, putting:
\set HISTFILE ~/.psql_history-:DBNAME
in ~/.psqlrc will cause psql to maintain a separate history for
each database.
Note
This feature was shamelessly plagiarized from Bash.
HISTSIZE
The maximum number of commands to store in the command history
(default 500). If set to a negative value, no limit is applied.
Note
This feature was shamelessly plagiarized from Bash.
HOST
The database server host you are currently connected to. This
is set every time you connect to a database (including program
start-up), but can be changed or unset.
IGNOREEOF
If set to 1 or less, sending an EOF character (usually
Control+D) to an interactive session of psql will terminate the
application. If set to a larger numeric value, that many
consecutive EOF characters must be typed to make an interactive
session terminate. If the variable is set to a non-numeric
value, it is interpreted as 10. The default is 0.
Note
This feature was shamelessly plagiarized from Bash.
LASTOID
The value of the last affected OID, as returned from an INSERT
or \lo_import command. This variable is only guaranteed to be
valid until after the result of the next SQL command has been
displayed. PostgreSQL servers since version 12 do not support
OID system columns anymore, thus LASTOID will always be 0
following INSERT when targeting such servers.
LAST_ERROR_MESSAGE
LAST_ERROR_SQLSTATE
The primary error message and associated SQLSTATE code for the
most recent failed query in the current psql session, or an
empty string and 00000 if no error has occurred in the current
session.
ON_ERROR_ROLLBACK
When set to on, if a statement in a transaction block generates
an error, the error is ignored and the transaction continues.
When set to interactive, such errors are only ignored in
interactive sessions, and not when reading script files. When
set to off (the default), a statement in a transaction block
that generates an error aborts the entire transaction. The
error rollback mode works by issuing an implicit SAVEPOINT for
you, just before each command that is in a transaction block,
and then rolling back to the savepoint if the command fails.
ON_ERROR_STOP
By default, command processing continues after an error. When
this variable is set to on, processing will instead stop
immediately. In interactive mode, psql will return to the
command prompt; otherwise, psql will exit, returning error code
3 to distinguish this case from fatal error conditions, which
are reported using error code 1. In either case, any currently
running scripts (the top-level script, if any, and any other
scripts which it may have in invoked) will be terminated
immediately. If the top-level command string contained multiple
SQL commands, processing will stop with the current command.
PORT
The database server port to which you are currently connected.
This is set every time you connect to a database (including
program start-up), but can be changed or unset.
PROMPT1
PROMPT2
PROMPT3
These specify what the prompts psql issues should look like.
See Prompting below.
QUIET
Setting this variable to on is equivalent to the command line
option -q. It is probably not too useful in interactive mode.
ROW_COUNT
The number of rows returned or affected by the last SQL query,
or 0 if the query failed or did not report a row count.
SERVER_VERSION_NAME
SERVER_VERSION_NUM
The server's version number as a string, for example 9.6.2,
10.1 or 11beta1, and in numeric form, for example 90602 or
100001. These are set every time you connect to a database
(including program start-up), but can be changed or unset.
SHOW_ALL_RESULTS
When this variable is set to off, only the last result of a
combined query (\;) is shown instead of all of them. The
default is on. The off behavior is for compatibility with older
versions of psql.
SHOW_CONTEXT
This variable can be set to the values never, errors, or always
to control whether CONTEXT fields are displayed in messages
from the server. The default is errors (meaning that context
will be shown in error messages, but not in notice or warning
messages). This setting has no effect when VERBOSITY is set to
terse or sqlstate. (See also \errverbose, for use when you want
a verbose version of the error you just got.)
SINGLELINE
Setting this variable to on is equivalent to the command line
option -S.
SINGLESTEP
Setting this variable to on is equivalent to the command line
option -s.
SQLSTATE
The error code (see Appendix A) associated with the last SQL
query's failure, or 00000 if it succeeded.
USER
The database user you are currently connected as. This is set
every time you connect to a database (including program
start-up), but can be changed or unset.
VERBOSITY
This variable can be set to the values default, verbose, terse,
or sqlstate to control the verbosity of error reports. (See
also \errverbose, for use when you want a verbose version of
the error you just got.)
VERSION
VERSION_NAME
VERSION_NUM
These variables are set at program start-up to reflect psql's
version, respectively as a verbose string, a short string
(e.g., 9.6.2, 10.1, or 11beta1), and a number (e.g., 90602 or
100001). They can be changed or unset.
SQL Interpolation
A key feature of psql variables is that you can substitute
("interpolate") them into regular SQL statements, as well as the
arguments of meta-commands. Furthermore, psql provides facilities
for ensuring that variable values used as SQL literals and
identifiers are properly quoted. The syntax for interpolating a
value without any quoting is to prepend the variable name with a
colon (:). For example,
testdb=> \set foo 'my_table'
testdb=> SELECT * FROM :foo;
would query the table my_table. Note that this may be unsafe: the
value of the variable is copied literally, so it can contain
unbalanced quotes, or even backslash commands. You must make sure
that it makes sense where you put it.
When a value is to be used as an SQL literal or identifier, it is
safest to arrange for it to be quoted. To quote the value of a
variable as an SQL literal, write a colon followed by the variable
name in single quotes. To quote the value as an SQL identifier,
write a colon followed by the variable name in double quotes. These
constructs deal correctly with quotes and other special characters
embedded within the variable value. The previous example would be
more safely written this way:
testdb=> \set foo 'my_table'
testdb=> SELECT * FROM :"foo";
Variable interpolation will not be performed within quoted SQL
literals and identifiers. Therefore, a construction such as ':foo'
doesn't work to produce a quoted literal from a variable's value
(and it would be unsafe if it did work, since it wouldn't correctly
handle quotes embedded in the value).
One example use of this mechanism is to copy the contents of a file
into a table column. First load the file into a variable and then
interpolate the variable's value as a quoted string:
testdb=> \set content `cat my_file.txt`
testdb=> INSERT INTO my_table VALUES (:'content');
(Note that this still won't work if my_file.txt contains NUL bytes.
psql does not support embedded NUL bytes in variable values.)
Since colons can legally appear in SQL commands, an apparent
attempt at interpolation (that is, :name, :'name', or :"name") is
not replaced unless the named variable is currently set. In any
case, you can escape a colon with a backslash to protect it from
substitution.
The :{?name} special syntax returns TRUE or FALSE depending on
whether the variable exists or not, and is thus always substituted,
unless the colon is backslash-escaped.
The colon syntax for variables is standard SQL for embedded query
languages, such as ECPG. The colon syntaxes for array slices and
type casts are PostgreSQL extensions, which can sometimes conflict
with the standard usage. The colon-quote syntax for escaping a
variable's value as an SQL literal or identifier is a psql
extension.
Prompting
The prompts psql issues can be customized to your preference. The
three variables PROMPT1, PROMPT2, and PROMPT3 contain strings and
special escape sequences that describe the appearance of the
prompt. Prompt 1 is the normal prompt that is issued when psql
requests a new command. Prompt 2 is issued when more input is
expected during command entry, for example because the command was
not terminated with a semicolon or a quote was not closed. Prompt 3
is issued when you are running an SQL COPY FROM STDIN command and
you need to type in a row value on the terminal.
The value of the selected prompt variable is printed literally,
except where a percent sign (%) is encountered. Depending on the
next character, certain other text is substituted instead. Defined
substitutions are:
%M
The full host name (with domain name) of the database server,
or [local] if the connection is over a Unix domain socket, or
[local:/dir/name], if the Unix domain socket is not at the
compiled in default location.
%m
The host name of the database server, truncated at the first
dot, or [local] if the connection is over a Unix domain socket.
%>
The port number at which the database server is listening.
%n
The database session user name. (The expansion of this value
might change during a database session as the result of the
command SET SESSION AUTHORIZATION.)
%/
The name of the current database.
%~
Like %/, but the output is ~ (tilde) if the database is your
default database.
%#
If the session user is a database superuser, then a #,
otherwise a >. (The expansion of this value might change during
a database session as the result of the command SET SESSION
AUTHORIZATION.)
%p
The process ID of the backend currently connected to.
%R
In prompt 1 normally =, but @ if the session is in an inactive
branch of a conditional block, or ^ if in single-line mode, or
! if the session is disconnected from the database (which can
happen if \connect fails). In prompt 2 %R is replaced by a
character that depends on why psql expects more input: - if the
command simply wasn't terminated yet, but * if there is an
unfinished /* ... */ comment, a single quote if there is an
unfinished quoted string, a double quote if there is an
unfinished quoted identifier, a dollar sign if there is an
unfinished dollar-quoted string, or ( if there is an unmatched
left parenthesis. In prompt 3 %R doesn't produce anything.
%x
Transaction status: an empty string when not in a transaction
block, or * when in a transaction block, or ! when in a failed
transaction block, or ? when the transaction state is
indeterminate (for example, because there is no connection).
%l
The line number inside the current statement, starting from 1.
%digits
The character with the indicated octal code is substituted.
%:name:
The value of the psql variable name. See Variables, above, for
details.
%`command`
The output of command, similar to ordinary "back-tick"
substitution.
%[ ... %]
Prompts can contain terminal control characters which, for
example, change the color, background, or style of the prompt
text, or change the title of the terminal window. In order for
the line editing features of Readline to work properly, these
non-printing control characters must be designated as invisible
by surrounding them with %[ and %]. Multiple pairs of these can
occur within the prompt. For example:
testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '
results in a boldfaced (1;) yellow-on-black (33;40) prompt on
VT100-compatible, color-capable terminals.
%w
Whitespace of the same width as the most recent output of
PROMPT1. This can be used as a PROMPT2 setting, so that
multi-line statements are aligned with the first line, but
there is no visible secondary prompt.
To insert a percent sign into your prompt, write %%. The default
prompts are '%/%R%x%# ' for prompts 1 and 2, and '>> ' for prompt
3.
Note
This feature was shamelessly plagiarized from tcsh.
Command-Line Editing
psql uses the Readline or libedit library, if available, for
convenient line editing and retrieval. The command history is
automatically saved when psql exits and is reloaded when psql
starts up. Type up-arrow or control-P to retrieve previous lines.
You can also use tab completion to fill in partially-typed keywords
and SQL object names in many (by no means all) contexts. For
example, at the start of a command, typing ins and pressing TAB
will fill in insert into. Then, typing a few characters of a table
or schema name and pressing TAB will fill in the unfinished name,
or offer a menu of possible completions when there's more than one.
(Depending on the library in use, you may need to press TAB more
than once to get a menu.)
Tab completion for SQL object names requires sending queries to the
server to find possible matches. In some contexts this can
interfere with other operations. For example, after BEGIN it will
be too late to issue SET TRANSACTION ISOLATION LEVEL if a
tab-completion query is issued in between. If you do not want tab
completion at all, you can turn it off permanently by putting this
in a file named .inputrc in your home directory:
$if psql
set disable-completion on
$endif
(This is not a psql but a Readline feature. Read its documentation
for further details.)
The -n (--no-readline) command line option can also be useful to
disable use of Readline for a single run of psql. This prevents tab
completion, use or recording of command line history, and editing
of multi-line commands. It is particularly useful when you need to
copy-and-paste text that contains TAB characters.
ENVIRONMENT
COLUMNS
If \pset columns is zero, controls the width for the wrapped format
and width for determining if wide output requires the pager or
should be switched to the vertical format in expanded auto mode.
PGDATABASE
PGHOST
PGPORT
PGUSER
Default connection parameters (see Section 34.15).
PG_COLOR
Specifies whether to use color in diagnostic messages. Possible
values are always, auto and never.
PSQL_EDITOR
EDITOR
VISUAL
Editor used by the \e, \ef, and \ev commands. These variables are
examined in the order listed; the first that is set is used. If
none of them is set, the default is to use vi on Unix systems or
notepad.exe on Windows systems.
PSQL_EDITOR_LINENUMBER_ARG
When \e, \ef, or \ev is used with a line number argument, this
variable specifies the command-line argument used to pass the
starting line number to the user's editor. For editors such as
Emacs or vi, this is a plus sign. Include a trailing space in the
value of the variable if there needs to be space between the option
name and the line number. Examples:
PSQL_EDITOR_LINENUMBER_ARG='+'
PSQL_EDITOR_LINENUMBER_ARG='--line '
The default is + on Unix systems (corresponding to the default
editor vi, and useful for many other common editors); but there is
no default on Windows systems.
PSQL_HISTORY
Alternative location for the command history file. Tilde (~)
expansion is performed.
PSQL_PAGER
PAGER
If a query's results do not fit on the screen, they are piped
through this command. Typical values are more or less. Use of the
pager can be disabled by setting PSQL_PAGER or PAGER to an empty
string, or by adjusting the pager-related options of the \pset
command. These variables are examined in the order listed; the
first that is set is used. If neither of them is set, the default
is to use more on most platforms, but less on Cygwin.
PSQL_WATCH_PAGER
When a query is executed repeatedly with the \watch command, a
pager is not used by default. This behavior can be changed by
setting PSQL_WATCH_PAGER to a pager command, on Unix systems. The
pspg pager (not part of PostgreSQL but available in many open
source software distributions) can display the output of \watch if
started with the option --stream.
PSQLRC
Alternative location of the user's .psqlrc file. Tilde (~)
expansion is performed.
SHELL
Command executed by the \! command.
TMPDIR
Directory for storing temporary files. The default is /tmp.
This utility, like most other PostgreSQL utilities, also uses the
environment variables supported by libpq (see Section 34.15).
FILES
psqlrc and ~/.psqlrc
Unless it is passed an -X option, psql attempts to read and execute
commands from the system-wide startup file (psqlrc) and then the
user's personal startup file (~/.psqlrc), after connecting to the
database but before accepting normal commands. These files can be
used to set up the client and/or the server to taste, typically
with \set and SET commands.
The system-wide startup file is named psqlrc. By default it is
sought in the installation's "system configuration" directory,
which is most reliably identified by running pg_config
--sysconfdir. Typically this directory will be ../etc/ relative to
the directory containing the PostgreSQL executables. The directory
to look in can be set explicitly via the PGSYSCONFDIR environment
variable.
The user's personal startup file is named .psqlrc and is sought in
the invoking user's home directory. On Windows the personal startup
file is instead named %APPDATA%\postgresql\psqlrc.conf. In either
case, this default file path can be overridden by setting the
PSQLRC environment variable.
Both the system-wide startup file and the user's personal startup
file can be made psql-version-specific by appending a dash and the
PostgreSQL major or minor release identifier to the file name, for
example ~/.psqlrc-15 or ~/.psqlrc-15.8. The most specific
version-matching file will be read in preference to a
non-version-specific file. These version suffixes are added after
determining the file path as explained above.
.psql_history
The command-line history is stored in the file ~/.psql_history, or
%APPDATA%\postgresql\psql_history on Windows.
The location of the history file can be set explicitly via the
HISTFILE psql variable or the PSQL_HISTORY environment variable.
NOTES
o psql works best with servers of the same or an older major version.
Backslash commands are particularly likely to fail if the server is
of a newer version than psql itself. However, backslash commands of
the \d family should work with servers of versions back to 9.2,
though not necessarily with servers newer than psql itself. The
general functionality of running SQL commands and displaying query
results should also work with servers of a newer major version, but
this cannot be guaranteed in all cases.
If you want to use psql to connect to several servers of different
major versions, it is recommended that you use the newest version
of psql. Alternatively, you can keep around a copy of psql from
each major version and be sure to use the version that matches the
respective server. But in practice, this additional complication
should not be necessary.
o Before PostgreSQL 9.6, the -c option implied -X (--no-psqlrc); this
is no longer the case.
o Before PostgreSQL 8.4, psql allowed the first argument of a
single-letter backslash command to start directly after the
command, without intervening whitespace. Now, some whitespace is
required.
NOTES FOR WINDOWS USERS
psql is built as a "console application". Since the Windows console
windows use a different encoding than the rest of the system, you must
take special care when using 8-bit characters within psql. If psql
detects a problematic console code page, it will warn you at startup.
To change the console code page, two things are necessary:
o Set the code page by entering cmd.exe /c chcp 1252. (1252 is a code
page that is appropriate for German; replace it with your value.)
If you are using Cygwin, you can put this command in /etc/profile.
o Set the console font to Lucida Console, because the raster font
does not work with the ANSI code page.
EXAMPLES
The first example shows how to spread a command over several lines of
input. Notice the changing prompt:
testdb=> CREATE TABLE my_table (
testdb(> first integer not null default 0,
testdb(> second text)
testdb-> ;
CREATE TABLE
Now look at the table definition again:
testdb=> \d my_table
Table "public.my_table"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
first | integer | | not null | 0
second | text | | |
Now we change the prompt to something more interesting:
testdb=> \set PROMPT1 '%n@%m %~%R%# '
peter@localhost testdb=>
Let's assume you have filled the table with data and want to take a
look at it:
peter@localhost testdb=> SELECT * FROM my_table;
first | second
-------+--------
1 | one
2 | two
3 | three
4 | four
(4 rows)
You can display tables in different ways by using the \pset command:
peter@localhost testdb=> \pset border 2
Border style is 2.
peter@localhost testdb=> SELECT * FROM my_table;
+-------+--------+
| first | second |
+-------+--------+
| 1 | one |
| 2 | two |
| 3 | three |
| 4 | four |
+-------+--------+
(4 rows)
peter@localhost testdb=> \pset border 0
Border style is 0.
peter@localhost testdb=> SELECT * FROM my_table;
first second
----- ------
1 one
2 two
3 three
4 four
(4 rows)
peter@localhost testdb=> \pset border 1
Border style is 1.
peter@localhost testdb=> \pset format csv
Output format is csv.
peter@localhost testdb=> \pset tuples_only
Tuples only is on.
peter@localhost testdb=> SELECT second, first FROM my_table;
one,1
two,2
three,3
four,4
peter@localhost testdb=> \pset format unaligned
Output format is unaligned.
peter@localhost testdb=> \pset fieldsep '\t'
Field separator is " ".
peter@localhost testdb=> SELECT second, first FROM my_table;
one 1
two 2
three 3
four 4
Alternatively, use the short commands:
peter@localhost testdb=> \a \t \x
Output format is aligned.
Tuples only is off.
Expanded display is on.
peter@localhost testdb=> SELECT * FROM my_table;
-[ RECORD 1 ]-
first | 1
second | one
-[ RECORD 2 ]-
first | 2
second | two
-[ RECORD 3 ]-
first | 3
second | three
-[ RECORD 4 ]-
first | 4
second | four
Also, these output format options can be set for just one query by
using \g:
peter@localhost testdb=> SELECT * FROM my_table
peter@localhost testdb-> \g (format=aligned tuples_only=off expanded=on)
-[ RECORD 1 ]-
first | 1
second | one
-[ RECORD 2 ]-
first | 2
second | two
-[ RECORD 3 ]-
first | 3
second | three
-[ RECORD 4 ]-
first | 4
second | four
Here is an example of using the \df command to find only functions with
names matching int*pl and whose second argument is of type bigint:
testdb=> \df int*pl * bigint
List of functions
Schema | Name | Result data type | Argument data types | Type
------------+---------+------------------+---------------------+------
pg_catalog | int28pl | bigint | smallint, bigint | func
pg_catalog | int48pl | bigint | integer, bigint | func
pg_catalog | int8pl | bigint | bigint, bigint | func
(3 rows)
When suitable, query results can be shown in a crosstab representation
with the \crosstabview command:
testdb=> SELECT first, second, first > 2 AS gt2 FROM my_table;
first | second | gt2
-------+--------+-----
1 | one | f
2 | two | f
3 | three | t
4 | four | t
(4 rows)
testdb=> \crosstabview first second
first | one | two | three | four
-------+-----+-----+-------+------
1 | f | | |
2 | | f | |
3 | | | t |
4 | | | | t
(4 rows)
This second example shows a multiplication table with rows sorted in
reverse numerical order and columns with an independent, ascending
numerical order.
testdb=> SELECT t1.first as "A", t2.first+100 AS "B", t1.first*(t2.first+100) as "AxB",
testdb(> row_number() over(order by t2.first) AS ord
testdb(> FROM my_table t1 CROSS JOIN my_table t2 ORDER BY 1 DESC
testdb(> \crosstabview "A" "B" "AxB" ord
A | 101 | 102 | 103 | 104
---+-----+-----+-----+-----
4 | 404 | 408 | 412 | 416
3 | 303 | 306 | 309 | 312
2 | 202 | 204 | 206 | 208
1 | 101 | 102 | 103 | 104
(4 rows)
PostgreSQL 15.8 2024 psql(1)
postgresql 15.8 - Generated Tue Aug 20 15:04:39 CDT 2024