psql — PostgreSQL interactive terminal
psql [option...] [dbname
[username]]
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.
-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
otherwise 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 53.2.2.1
for more details about how the server handles multi-query strings.)
Also, psql only prints the
result of the last SQL command in the string.
This is different from the behavior when the same string is read from
a file or fed to psql's standard input,
because then psql sends
each SQL command separately.
Because of this behavior, putting more than one SQL command in a
single -c string often has unexpected results.
It's better to 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
-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
< . In general,
both will do what you expect, but using filename-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=hostnameSpecifies 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
Turn on HTML tabular output. 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-readlineDo not use Readline for line editing and do not use the command history. This can be useful to turn off tab expansion when cutting and pasting.
-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-stepRun 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-lineRuns in single-line mode where a newline terminates an SQL command, as a semicolon does.
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--versionPrint 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--passwordForce 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. 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.
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.
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 34.14.) It is also convenient to have a
~/.pgpass file to avoid regularly having to type in
passwords. See Section 34.15 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 34.17. 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.
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 (11.20)
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.
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.
The forms :' 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.
variable_name}
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 : where
variable_namevariable_name is a psql variable name
are replaced by the variable's value. Also, appearances of
:' 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.
variable_name'
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, processing will immediately stop with an error. 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.
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 . (The name of
this command derives from “caption”, as it was
previously only used to set the caption in an
HTML table.)
title
\cd [ directory ]
Changes the current working directory to
directory. Without argument, changes
to the current user's home directory.
To print your current working directory, use \! pwd.
\conninfoOutputs information about the current database connection.
\copy { table [ ( column_list ) ] | ( query ) }
{ from | to }
{ 'filename' | program 'command' | stdin | stdout | pstdin | 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 a SQL script file.
For \copy ... to stdout, output is sent to the same place
as psql command output, and
the COPY 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 count\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.
Another way to obtain the same result as \copy
... to is to use the SQL COPY
... TO STDOUT command and terminate it
with \g
or filename\g |.
Unlike program\copy, this method allows the command to
span multiple lines; also, variable interpolation and backquote
expansion can be used.
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.
\copyrightShows 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.
By default, only user-created objects are shown; supply a
pattern or the S modifier to include system
objects.
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.
\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.
\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 under GRANT.
\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, \dit lists indexes
and tables. If + is
appended to the command name, each object is listed with its
physical size on disk and its 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 ACL, 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.
\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 ACL, options, and description of the foreign-data
wrapper are also shown.
\df[anptwS+] [ 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.
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.
To look up functions taking arguments or returning values of a specific
data type, use your pager's search capability to scroll through the
\df output.
\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.
\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 ]
Lists operators with their operand and result types.
If pattern is
specified, only operators 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,
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 under GRANT.
\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
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.
\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.
The new contents of the query buffer are then 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. Whatever remains
will wait in the query buffer; 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.
See under Environment for how to configure and customize your editor.
\echo text [ ... ]Prints the arguments to the standard output, separated by one space 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.
If you use the \o command to redirect your
query output you might wish to use \qecho
instead of this command.
\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.
After the editor exits, the updated command waits in the query buffer;
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.
See under Environment 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.
After the editor exits, the updated command waits in the query buffer;
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 [ filename ]\g [ |command ]Sends the current query buffer to the server for execution. If an 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 an argument is essentially equivalent to a semicolon.
A \g with argument is a “one-shot”
alternative to the \o command.
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.
\gdescShows 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.
\gexec
Sends the current query buffer to the server, then treats
each column of each row of the query's output (if any) as a 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->\gexecCREATE 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). 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 :var2hello 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_var2hello 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 [ filename ]\gx [ |command ]
\gx is equivalent to \g, but
forces expanded output mode for this query. See \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.
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.
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.
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_listShows a list of all PostgreSQL large objects currently stored in the database, along with any comments provided for them.
\lo_unlink loid
Deletes the large object with OID
loid from the
database.
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.
To intersperse text output in between query results, use
\qecho.
\p or \printPrint 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.
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- or
comma-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_zeroSets 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 ( count).
If n rows)value is omitted the
command toggles footer display on or off.
format
Sets the output format to one of unaligned,
aligned, wrapped,
html, asciidoc,
latex (uses tabular),
latex-longtable, or
troff-ms.
Unique abbreviations are allowed.
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).
aligned format is the standard, human-readable,
nicely formatted text output; this is the default.
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 html, asciidoc, 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. latex-longtable
also 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. If the environment variable PSQL_PAGER
or PAGER is set, the output is piped to the
specified program. Otherwise a platform-dependent default program
(such as more) is used.
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.
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.
recordsepSpecifies the record (line) separator to use in unaligned output format. The default is a newline character.
recordsep_zeroSets 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 the Examples section.
There are various shortcut commands for \pset. See
\a, \C, \f,
\H, \t, \T,
and \x.
\q or \quitQuits 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 \resetResets (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 the section 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.
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 lesstestdb=>\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.
\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 a 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 53.2.2.1
for more details about how the server handles multi-query strings.)
psql prints only the last query result
it receives for each request; in this example, although all
three SELECTs are indeed executed, psql
only prints the 3.
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 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.
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 .,
( for
R+|)R*( for
R|)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).
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.
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).
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.
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.
DBNAMEThe 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.
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.
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.
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.
This feature was shamelessly plagiarized from Bash.
HISTSIZEThe maximum number of commands to store in the command history (default 500). If set to a negative value, no limit is applied.
This feature was shamelessly plagiarized from Bash.
HOSTThe 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.
IGNOREEOFIf 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.
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.
LAST_ERROR_MESSAGELAST_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.
PORTThe 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.
PROMPT1PROMPT2PROMPT3These 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_COUNTThe 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_NAMESERVER_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_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.
(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.
USERThe 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, or terse to control the verbosity
of error reports.
(See also \errverbose, for use when you want a verbose
version of the error you just got.)
VERSIONVERSION_NAMEVERSION_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.
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 :{? 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.
name}
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.
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:,
if the Unix domain socket is not at the compiled in default
location.
/dir/name]
%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.)
%pThe 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.
%digitsThe character with the indicated octal code is substituted.
%:name:
The value of the psql variable
name. See the
section Variables 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.
To insert a percent sign into your prompt, write
%%. The default prompts are
'%/%R%# ' for prompts 1 and 2, and
'>> ' for prompt 3.
This feature was shamelessly plagiarized from tcsh.
psql supports the Readline
library for convenient line editing and retrieval. The command
history is automatically saved when psql
exits and is reloaded when
psql starts up. Tab-completion is also
supported, although the completion logic makes no claim to be an
SQL parser. The queries generated by tab-completion
can also interfere with other SQL commands, e.g., SET
TRANSACTION ISOLATION LEVEL.
If for some reason you do not like the tab completion, you
can turn it off 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.)
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.
PGDATABASEPGHOSTPGPORTPGUSERDefault connection parameters (see Section 34.14).
PSQL_EDITOREDITORVISUAL
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_PAGERPAGER
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 none of them is set, the default is to use more on most
platforms, but less on Cygwin.
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 34.14).
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 and is
sought in the installation's “system configuration” directory,
which is most reliably identified by running pg_config
--sysconfdir. By default this directory will be ../etc/
relative to the directory containing
the PostgreSQL executables. The name of this
directory 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, which
lacks such a concept, the personal startup file is named
%APPDATA%\postgresql\psqlrc.conf.
The location of the user's startup file can be set explicitly via
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 number to the file name,
for example ~/.psqlrc-9.2 or
~/.psqlrc-9.2.5. The most specific
version-matching file will be read in preference to a
non-version-specific file.
.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.
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 7.4, 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.
Before PostgreSQL 9.6,
the -c option implied -X
(--no-psqlrc); this is no longer the case.
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.
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:
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.
Set the console font to Lucida Console, because the
raster font does not work with the ANSI code page.
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 2Border 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 0Border 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 1Border style is 1. peter@localhost testdb=>\pset format unalignedOutput format is unaligned. peter@localhost testdb=>\pset fieldsep ","Field separator is ",". peter@localhost testdb=>\pset tuples_onlyShowing only tuples. 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 \xOutput 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
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 secondfirst | 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 ordtestdb(>FROM my_table t1 CROSS JOIN my_table t2 ORDER BY 1 DESCtestdb(>\crosstabview "A" "B" "AxB" ordA | 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)