/* Void Main's man pages */
{ phpMan } else { main(); }
PSQL(1) PostgreSQL Client Applications PSQL(1)
NAME
psql - PostgreSQL interactive terminal
SYNOPSIS
psql [ option... ] [ dbname
[ username ] ]
DESCRIPTION
psql is a terminal-based front-end to PostgreSQL. It enables you to type in queries interactively, issue them to Post-
greSQL, and see the query results. Alternatively, input can be from a file. In addition, it provides a number of meta-
commands and various shell-like features to facilitate writing scripts and automating a wide variety of tasks.
OPTIONS
-a
--echo-all
Print all input lines to standard output as they are read. This is more useful for script processing rather than
interactive mode. 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.)
-c command
--command command
Specifies that psql is to execute one command string, command, and then exit. This is useful in shell scripts.
command must be either a command string that is completely parsable by the server (i.e., it contains no psql spe-
cific features), or a single backslash command. Thus you cannot mix SQL and psql meta-commands with this option.
To achieve that, you could pipe the string into psql, like this: echo '\x \\ SELECT * FROM foo;' | psql. (\\ is
the separator meta-command.)
If the command string contains multiple SQL commands, they are processed in a single transaction, unless there are
explicit BEGIN/COMMIT commands included in the string to divide it into multiple transactions. This is different
from the behavior when the same string is fed to psql's standard input.
-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.
If this parameter contains an = sign, it is treated as a conninfo string. See in the documentation for more infor-
mation.
-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 from within psql.
-f filename
--file filename
Use the file filename as the source of commands instead of reading commands interactively. After the file is pro-
cessed, psql terminates. This is in many ways equivalent to the internal command \i.
If filename is - (hyphen), then standard input is read.
Using this option is subtly different from writing psql < filename. In general, both will do what you expect, but
using -f enables some nice features such as error messages with line numbers. There is also a slight chance that
using this option will reduce the start-up overhead. On the other hand, the variant using the shell's input redi-
rection is (in theory) guaranteed to yield exactly the same output that you would have gotten had you entered
everything by hand.
-F separator
--field-separator separator
Use separator as the field separator for unaligned output. This is equivalent to \pset fieldsep or \f.
-h hostname
--host hostname
Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is
used as the directory for the Unix-domain socket.
-H
--html 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 internal
command \list.
-L filename
--log-file filename
Write all query output into file filename, in addition to the normal output destination.
-n
--no-readline
Do not use readline for line editing and do not use the 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 connec-
tions. 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
Allows you to specify printing options in the style of \pset on the command line. Note that here you have to sepa-
rate name and value with an equal sign instead of a space. Thus 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. Within psql you can also
set the QUIET variable to achieve the same effect.
-R separator
--record-separator separator
Use separator as the record separator for unaligned output. This is equivalent to the \pset recordsep command.
-s
--single-step
Run in single-step mode. That means the user is prompted before each command is sent to the server, with the
option to cancel execution as well. Use this to debug scripts.
-S
--single-line
Runs in single-line mode where a newline terminates an SQL command, as a semicolon does.
Note: This mode is provided for those who insist on it, but you are not necessarily encouraged to use it. In par-
ticular, if you mix SQL and meta-commands on a line the order of execution might not always be clear to the inex-
perienced user.
-t
--tuples-only
Turn off printing of column names and result row count footers, etc. This is equivalent to the \t command.
-T table_options
--table-attr table_options
Allows you to specify options to be placed within the HTML table tag. See \pset 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 internal 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 just set a variable with-
out a value, use the equal sign but leave off the value. These assignments are done during a very early stage of
start-up, so variables reserved for internal purposes might get overwritten later.
-V
--version
Print the psql version and exit.
-w
--no-password
Never issue a password prompt. If the server requires password authentication and a password is not available by
other means such as a .pgpass file, the connection attempt will fail. This option can be useful in batch jobs and
scripts where no user is present to enter a password.
Note that this option will remain set for the entire session, and so it affects uses of the meta-command \connect
as well as the initial connection attempt.
-W
--password
Force psql to prompt for a password before connecting to a database.
This option is never essential, since psql will automatically prompt for a password if the server demands password
authentication. 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 the \x command.
-X,
--no-psqlrc
Do not read the start-up file (neither the system-wide psqlrc file nor the user's ~/.psqlrc file).
-1
--single-transaction
When psql executes a script with the -f option, adding this option wraps BEGIN/COMMIT around the script to execute
it as a single transaction. This ensures that either all the commands complete successfully, or no changes are
applied.
If the script itself uses BEGIN, COMMIT, or ROLLBACK, this option will not have the desired effects. Also, if the
script contains any command that cannot be executed inside a transaction block, specifying this option will cause
that command (and hence the whole transaction) to fail.
-?
--help Show help about psql command line arguments, and exit.
EXIT STATUS
psql returns 0 to the shell if it finished normally, 1 if a fatal error of its own (out of memory, file not found)
occurs, 2 if the connection to the server went bad and the session was not interactive, and 3 if an error occurred in a
script and the variable ON_ERROR_STOP was set.
USAGE
CONNECTING TO A DATABASE
psql is a regular PostgreSQL client application. In order to connect to a database you need to know the name of your tar-
get 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 these options are required; there are useful defaults. If you omit the host name, psql will con-
nect 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 Unix 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 in the documentation.) It
is also convenient to have a ~/.pgpass file to avoid regularly having to type in passwords. See in the documentation for
more information.
An alternative way to specify connection parameters is in a conninfo string, 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"
This way you can also use LDAP for connection parameter lookup as described in in the documentation. See in the documen-
tation 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.
ENTERING SQL COMMANDS
In normal operation, psql provides a prompt with the name of the database to which psql is currently connected, followed
by the string =>. For example:
$ psql testdb
psql (8.4.9)
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-termi-
nating 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.
Whenever a command is executed, psql also polls for asynchronous notification events generated by LISTEN [listen(7)] and
NOTIFY [notify(7)].
META-COMMANDS
Anything you enter in psql that begins with an unquoted backslash is a psql meta-command that is processed by psql
itself. These commands help make psql more useful for administration or scripting. Meta-commands are more commonly 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 into an argument you can quote it with a single quote. To include a single quote into such an argu-
ment, use two single quotes. Anything contained in single quotes is furthermore subject to C-like substitutions for \n
(new line), \t (tab), \digits (octal), and \xdigits (hexadecimal).
If an unquoted argument begins with a colon (:), it is taken as a psql variable and the value of the variable is used as
the argument instead.
Arguments that are enclosed in backquotes (`) are taken as a command line that is passed to the shell. The output of the
command (with any trailing newline removed) is taken as the argument value. The above escape sequences also apply in
backquotes.
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 incorpo-
ration 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 when another unquoted backslash occurs. This is taken as the beginning of a new meta-com-
mand. 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.
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.
\cd [ directory ]
Changes the current working directory to directory. Without argument, changes to the current user's home direc-
tory.
Tip: To print your current working directory, use \! pwd.
\C [ title ]
Sets the title of any tables being printed as the result of a query or unset any such title. This command is
equivalent to \pset title title. (The name of this command derives from ``caption'', as it was previously only
used to set the caption in an HTML table.)
\connect (or \c) [ dbname [ username ] [ host ] [ port ] ]
Establishes a new connection to a PostgreSQL server. If the new connection is successfully made, the previous con-
nection is closed. If any of dbname, username, host or port are omitted or specified as -, the value of that
parameter from the previous connection is used. If there is no previous connection, the libpq default for the
parameter's value is used.
If the connection attempt failed (wrong user name, access denied, etc.), the previous connection will only be kept
if psql is in interactive mode. 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.
\copy { table [ ( column_list ) ] | ( query ) }
Performs a frontend (client) copy. This is an operation that runs an SQL COPY [copy(7)] 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.
The syntax of the command is similar to that of the SQL COPY [copy(7)] command. Note that, because of this, spe-
cial parsing rules apply to the \copy command. In particular, the variable substitution rules and backslash
escapes do not apply.
\copy ... from stdin | to stdout reads/writes based on the command input and output respectively. All rows are
read from the same source that issued the command, continuing until \. is read or the stream reaches EOF. Output
is sent to the same place as command output. To read/write from psql's standard input or output, use pstdin or
pstdout. This option is useful for populating tables in-line within a SQL script file.
Tip: This operation is not as efficient as the SQL COPY command because all data must pass through the
client/server connection. For large amounts of data the SQL command might be preferable.
\copyright
Shows the copyright and distribution terms of PostgreSQL.
\d[S+] [ pattern ]
For each relation (table, view, index, or sequence) matching the pattern, show all columns, their types, the
tablespace (if not the default) and any special attributes such as NOT NULL or defaults, if any. Associated
indexes, constraints, rules, and triggers are also shown, as is the view definition if the relation is a view.
(``Matching the pattern'' is defined below.)
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.
By default, only user-created objects are shown; supply a pattern or the S modifier to include system objects.
Note: If \d is used without a pattern argument, it is equivalent to \dtvs which will show a list of all tables,
views, and sequences. This is purely a convenience measure.
\da[S] [ pattern ]
Lists all available 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.
\db[+] [ pattern ]
Lists all available tablespaces. If pattern is specified, only tablespaces whose names match the pattern are
shown. If + is appended to the command name, each object is listed with its associated permissions.
\dc[S] [ pattern ]
Lists all available 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.
\dC [ pattern ]
Lists all available type casts. If pattern is specified, only casts whose source or target types match the pat-
tern are listed.
\dd[S] [ pattern ]
Shows the descriptions of objects matching the pattern, or of all visible objects 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. ``Object'' covers aggregates, functions, operators,
types, relations (tables, views, indexes, sequences), large objects, rules, and triggers. For example:
=> \dd version
Object descriptions
Schema | Name | Object | Description
------------+---------+----------+---------------------------
pg_catalog | version | function | PostgreSQL version string
(1 row)
Descriptions for objects can be created with the COMMENT [comment(7)] SQL command.
\dD[S] [ pattern ]
Lists all available domains. If pattern is specified, only matching domains are shown. By default, only user-cre-
ated objects are shown; supply a pattern or the S modifier to include system objects.
\des[+] [ pattern ]
Lists all 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, and options.
\deu[+] [ pattern ]
Lists all user mappings (mnemonic: ``external users''). If pattern is specified, only those mappings whose user
names match the pattern are listed. If the form \deu+ is used, additional information about each mapping is shown.
Caution: \deu+ might also display the user name and password of the remote user, so care should be taken not to
disclose them.
\dew[+] [ pattern ]
Lists all 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 and options of the
foreign-data wrapper are also shown.
\df[antwS+] [ pattern ]
Lists available functions, together with their arguments, return types, and their function types: 'agg' (aggre-
gate), 'normal', 'trigger', and 'window'. To display only functions of a specific type, use the corresponding let-
ters a, n, t, or w. If pattern is specified, only functions whose names match the pattern are shown. If the form
\df+ is used, additional information about each function, including volatility, language, source code and descrip-
tion, is shown. By default, only user-created objects are shown; supply a pattern or the S modifier to include
system objects.
Note: To look up functions taking arguments or returning values of a specific type, use your pager's search capa-
bility to scroll through the \df output.
\dF[+] [ pattern ]
Lists available 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 available text search dictionaries. If pattern is specified, only dictionaries whose names match the pat-
tern 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 available 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 available 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[+] [ pattern ]
Lists all database roles. If pattern is specified, only those roles whose names match the pattern are listed.
(This command is now effectively the same as \du). If the form \dg+ is used, additional information is shown
about each role, including the comment for each role.
\di[S+] [ pattern ]
\ds[S+] [ pattern ]
\dt[S+] [ pattern ]
\dv[S+] [ pattern ]
In this group of commands, the letters i, s, t, and v stand for index, sequence, table, and view, respectively.
You can specify any or all of these letters, in any order, to obtain a listing of all the matching objects. For
example, \dit lists indexes and tables. If + is appended to the command name, each object is listed with its phys-
ical size on disk and its associated description, if any. By default, only user-created objects are shown; supply
a pattern or the S modifier to include system objects.
If pattern is specified, only objects whose names match the pattern are listed.
\dl This is an alias for \lo_list, which shows a list of large objects.
\dn[+] [ pattern ]
Lists available schemas (namespaces). If pattern (a regular expression) is specified, only schemas whose names
match the pattern are listed. Non-local temporary schemas are suppressed. If + is appended to the command name,
each object is listed with its associated permissions and description, if any.
\do[S] [ pattern ]
Lists available operators with their operand and return 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.
\dp [ pattern ]
Lists available 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 [grant(7)] and REVOKE [revoke(7)] commands are used to set access privileges.
\dT[S+] [ pattern ]
Lists available 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, as well as its allowed val-
ues if it is an enum type. By default, only user-created objects are shown; supply a pattern or the S modifier to
include system objects.
\du[+] [ pattern ]
Lists all database 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, including the comment for each role.
\edit (or \e) [ filename ]
If filename is specified, the file is edited; after the editor exits, its content is copied back to the query buf-
fer. If no argument is given, the current query buffer is copied to a temporary file which is then edited in the
same fashion.
The new query buffer is then re-parsed according to the normal rules of psql, where the whole buffer is treated as
a single line. (Thus you cannot make scripts this way. Use \i for that.) This means also that if the query ends
with (or rather contains) a semicolon, it is immediately executed. In other cases it will merely wait in the query
buffer.
Tip: psql searches the environment variables PSQL_EDITOR, EDITOR, and VISUAL (in that order) for an editor to use.
If all of them are unset, vi is used on Unix systems, notepad.exe on Windows systems.
\ef [ function_description ]
This command fetches and edits the definition of the named function, in the form of a CREATE OR REPLACE FUNCTION
command. Editing is done in the same way as for \e. 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.
\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.
Tip: If you use the \o command to redirect your query output you might wish to use \qecho instead of this command.
\encoding [ encoding ]
Sets the client character set encoding. Without an argument, this command shows the current encoding.
\f [ string ]
Sets the field separator for unaligned query output. The default is the vertical bar (|). See also \pset for a
generic way of setting output options.
\g [ { filename | |command } ]
Sends the current query input buffer to the server and optionally stores the query's output in filename or pipes
the output into a separate Unix shell executing command. A bare \g is virtually equivalent to a semicolon. A \g
with argument is a ``one-shot'' alternative to the \o command.
\help (or \h) [ 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.
Note: To simplify typing, commands that consists of several words do not have to be quoted. Thus it is fine to
type \help alter table.
\H 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 filename
Reads input from the file filename and executes it as though it had been typed on the keyboard.
Note: If you want to see the lines on the screen as they are read you must set the variable ECHO to all.
\l (or \list)
\l+ (or \list+)
List the names, owners, character set encodings, and access privileges of all the databases in the server. 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 differ-
ent from the server function lo_export, which acts with the permissions of the user that the database server runs
as and on the server's file system.
Tip: Use \lo_list to find out the large object's OID.
\lo_import filename [ comment ]
Stores the file into a PostgreSQL large object. Optionally, it associates the given comment with the object. Exam-
ple:
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-cre-
ated large object in the future. For the sake of readability, it is recommended to always associate a human-read-
able comment with every object. Both OIDs and comments can be viewed with the \lo_list command.
Note that this command is subtly different from the server-side lo_import because it acts as the local user on the
local file system, rather than the server's user and file system.
\lo_list
Shows a list of all PostgreSQL large objects currently stored in the database, along with any comments provided
for them.
\lo_unlink loid
Deletes the large object with OID loid from the database.
Tip: Use \lo_list to find out the large object's OID.
\o [ {filename | |command} ]
Saves future query results to the file filename or pipes future results into a separate Unix shell to execute com-
mand. If no arguments are specified, the query output will be reset to the standard output.
``Query results'' includes all tables, command responses, and notices obtained from the database server, as well
as output of various backslash commands that query the database (such as \d), but not error messages.
Tip: To intersperse text output in between query results, use \qecho.
\p Print the current query buffer to the standard output.
\password [ username ]
Changes the password of the specified user (by default, the current user). This command prompts for the new pass-
word, 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 set variable name. An optional prompt, text, can be specified. (For multi-word prompts, use
single-quotes.)
By default, \prompt uses the terminal for input and output. However, if the -f command line switch is used,
\prompt uses standard input and standard output.
\pset parameter [ value ]
This command sets options affecting the output of query result tables. parameter describes which option is to be
set. The semantics of value depend thereon.
Adjustable printing options are:
format Sets the output format to one of unaligned, aligned, wrapped, html, latex, or troff-ms. Unique abbrevia-
tions are allowed. (That would mean one letter is enough.)
``Unaligned'' writes all columns of a row on a line, separated by the currently active field separator.
This is intended to create output that might be intended to be read in by other programs (tab-separated,
comma-separated). ``Aligned'' mode is the standard, human-readable, nicely formatted text output that is
default.
``Wrapped'' is like aligned but wraps output to the specified width. If \pset columns is zero (the
default), wrapped mode only affects screen output and wrapped width is controlled by the environment vari-
able COLUMNS or the detected screen width. If \pset columns is set to a non-zero value, all output is
wrapped, including file and pipe output.
The ``HTML'' and ``LaTeX'' modes 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 so dramatic in HTML, but
in LaTeX you must have a complete document wrapper.)
columns
Controls the target width for the wrapped format, and width for determining if wide output requires the
pager. Zero (the default) causes the wrapped format to affect only screen output.
border The second argument must be a number. In general, the higher the number the more borders and lines the
tables will have, but this depends on the particular format. In HTML mode, this will translate directly
into the border=... attribute, in the others only values 0 (no border), 1 (internal dividing lines), and 2
(table frame) make sense.
expanded (or x)
You can specify an optional second argument, if it is provided it may be either on or off which will enable
or disable expanded mode. If the second argument is not provided then we will toggle between regular and
expanded format. When expanded format is enabled, query results are displayed in two columns, with the col-
umn 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.
Expanded mode is supported by all four output formats.
null The second argument is a string that should be printed whenever a column is null. The default is not to
print anything, which can easily be mistaken for, say, an empty string. Thus, one might choose to write
\pset null '(null)'.
fieldsep
Specifies the field separator to be used in unaligned output mode. 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).
footer You can specify an optional second argument, if it is provided it may be either on or off which will enable
or disable display of the default footer (x rows). If the second argument is not provided then we will tog-
gle between on and off.
numericlocale
You can specify an optional second argument, if it is provided it may be either on or off which will enable
or disable display of a locale-aware character to separate groups of digits to the left of the decimal
marker. If the second argument is not provided then we will toggle between on and off.
recordsep
Specifies the record (line) separator to use in unaligned output mode. The default is a newline character.
tuples_only (or t)
You can specify an optional second argument, if it is provided it may be either on or off which will enable
or disable the tuples only mode. If the second argument is not provided then we will toggle between tuples
only and full display. Full display shows extra information such as column headers, titles, and various
footers. In tuples only mode, only actual table data is shown.
title [ text ]
Sets the table title for any subsequently printed tables. This can be used to give your output descriptive
tags. If no argument is given, the title is unset.
tableattr (or T) [ text ]
Allows you to specify any attributes to be placed inside the HTML 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.
pager Controls use of a pager for query and psql help output. If the environment variable PAGER is set, the out-
put is piped to the specified program. Otherwise a platform-dependent default (such as more) is used.
When the pager is off, the pager is not used. When the pager is on, the pager is used only when appropri-
ate, i.e. the output is to a terminal and will not fit on the screen. \pset pager turns the pager on and
off. Pager can also be set to always, which causes the pager to be always used.
Illustrations on how these different formats look can be seen in the Examples [psql(1)] section.
Tip: There are various shortcut commands for \pset. See \a, \C, \H, \t, \T, and \x.
Note: It is an error to call \pset without arguments. In the future this call might show the current status of all
printing options.
\q Quits the psql program.
\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 Resets (clears) the query buffer.
\s [ filename ]
Print or save the command line history to filename. If filename is omitted, the history is written to the standard
output. This option is only available if psql is configured to use the GNU Readline library.
\set [ name [ value [ ... ] ] ]
Sets the internal variable name to value or, if more than one value is given, to the concatenation of all of them.
If no second argument is given, the variable is just set with no value. To unset a variable, use the \unset com-
mand.
Valid variable names can contain characters, digits, and underscores. See the section Variables [psql(1)] below
for details. Variable names are case-sensitive.
Although you are welcome to set any variable to anything you want, psql treats several variables as special. They
are documented in the section about variables.
Note: This command is totally separate from the SQL command SET [set(7)].
\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
Allows you to specify attributes to be placed within the table tag in HTML tabular output mode. This command is
equivalent to \pset tableattr table_options.
\timing [ on | off ]
Without parameter, toggles a display of how long each SQL statement takes, in milliseconds. With parameter, sets
same.
\w {filename | |command}
Outputs the current query buffer to the file filename or pipes it to the Unix command command.
\x Toggles expanded table formatting mode. As such it is equivalent to \pset expanded.
\z [ pattern ]
Produces a list of all available tables, views and sequences with their associated access privileges. If a pat-
tern is specified, only tables,views and sequences whose names match the pattern are listed.
The GRANT [grant(7)] and REVOKE [revoke(7)] commands are used to set access privileges.
This is an alias for \dp (``display privileges'').
\! [ command ]
Escapes to a separate Unix shell or executes the Unix command command. The arguments are not further interpreted,
the shell will see them as is.
\? Shows help information about the backslash commands.
PATTERNS
The various \d commands accept a pattern parameter to specify the object name(s) to be displayed. In the simplest case, a
pattern is just the exact name of the object. The characters within a pattern are normally folded to lower case, just as
in SQL names; for example, \dt FOO will display the table named foo. As in SQL names, placing double quotes around a pat-
tern 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.
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 all 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 exam-
ple, \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 in the documentation, except for . which is taken as a separa-
tor as mentioned above, * which is translated to the regular-expression notation .*, ? which is translated to ., and $
which is matched literally. You can emulate these pattern characters at need by writing ? for ., (R+|) for R*, or (R|)
for R?. $ is not needed as a regular-expression character since the pattern must match the whole name, unlike the usual
interpretation of regular expressions (in other words, $ is automatically appended to your pattern). Write * at the
beginning and/or end if you don't wish the pattern to be anchored. Note that within double quotes, all regular expres-
sion special characters lose their special meanings and are matched literally. Also, the regular expression special char-
acters are matched literally in operator name patterns (i.e., the argument of \do).
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 the pattern *. To see all objects in the database, use the pattern
*.*.
ADVANCED FEATURES
VARIABLES
psql provides variable substitution features similar to common Unix command shells. Variables are simply name/value
pairs, where the value can be any string of any length. To set variables, use the psql meta-command \set:
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 and use it
as the argument of any slash command:
testdb=> \echo :foo
bar
Note: The arguments of \set are subject to the same substitution rules as with other commands. Thus you can con-
struct 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.
If you call \set without a second argument, the variable is set, with an empty string as value. To unset (or delete) a
variable, use the command \unset.
psql's internal variable names can consist of letters, numbers, and underscores in any order and any number of them. A
number of these variables are treated specially by psql. They indicate certain option settings that can be changed at run
time by altering the value of the variable or represent some state of the application. Although you can use these vari-
ables for any other purpose, this is not recommended, as the program behavior might grow really strange really quickly.
By convention, all specially treated variables consist of all upper-case letters (and possibly numbers and underscores).
To ensure maximum compatibility in the future, avoid using such variable names for your own purposes. A list of all spe-
cially treated variables follows.
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 trans-
action-control command, nor a command that cannot be executed inside a transaction block (such as VACUUM).
Note: In autocommit-off mode, you must explicitly abandon any failed transaction by entering ABORT or ROLLBACK.
Also keep in mind that if you exit the session without committing, your work will be lost.
Note: The autocommit-on mode is PostgreSQL's traditional behavior, but autocommit-off is closer to the SQL spec.
If you prefer autocommit-off, you might wish to set it in the system-wide psqlrc file or your ~/.psqlrc file.
DBNAME The name of the database you are currently connected to. This is set every time you connect to a database (includ-
ing program start-up), but can be unset.
ECHO If set to all, all lines entered from the keyboard or from a script are written to the standard output before they
are parsed or executed. To select this behavior on program start-up, use the switch -a. If set to queries, psql
merely prints all queries as they are sent to the server. The switch for this is -e.
ECHO_HIDDEN
When this variable is set and a backslash command queries the database, the query is first shown. This way you can
study the 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 the variable to the value noexec, the queries are just shown but
are not actually sent to the server and executed.
ENCODING
The current client character set encoding.
FETCH_COUNT
If this variable is set to an integer value > 0, the results of SELECT queries are fetched and displayed in groups
of that many rows, rather than the default behavior of collecting the entire result set before display. Therefore
only a limited amount of memory is used, regardless of the size of the result set. Settings of 100 to 1000 are
commonly used when enabling this feature. Keep in mind that when using this feature, a query might fail after
having already displayed some rows.
Tip: Although you can use any output format with this feature, the default aligned format tends to look bad
because each group of FETCH_COUNT rows will be formatted separately, leading to varying column widths across the
row groups. The other output formats work better.
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 com-
bines the two options. If unset, or if set to any other value than those above, all lines read in interactive mode
are saved on the history list.
Note: This feature was shamelessly plagiarized from Bash.
HISTFILE
The file name that will be used to store the history list. The default value is ~/.psql_history. For example,
putting:
\set HISTFILE ~/.psql_history- :DBNAME
in ~/.psqlrc will cause psql to maintain a separate history for each database.
Note: This feature was shamelessly plagiarized from Bash.
HISTSIZE
The number of commands to store in the command history. The default value is 500.
Note: This feature was shamelessly plagiarized from Bash.
HOST The database server host you are currently connected to. This is set every time you connect to a database (includ-
ing program start-up), but can be unset.
IGNOREEOF
If unset, sending an EOF character (usually Control+D) to an interactive session of psql will terminate the appli-
cation. If set to a numeric value, that many EOF characters are ignored before the application terminates. If the
variable is set but has no numeric value, the default is 10.
Note: This feature was shamelessly plagiarized from Bash.
LASTOID
The value of the last affected OID, as returned from an INSERT or lo_insert command. This variable is only guaran-
teed to be valid until after the result of the next SQL command has been displayed.
ON_ERROR_ROLLBACK
When on, if a statement in a transaction block generates an error, the error is ignored and the transaction con-
tinues. When interactive, such errors are only ignored in interactive sessions, and not when reading script files.
When off (the default), a statement in a transaction block that generates an error aborts the entire transaction.
The on_error_rollback-on mode works by issuing an implicit SAVEPOINT for you, just before each command that is in
a transaction block, and rolls back to the savepoint on error.
ON_ERROR_STOP
By default, if non-interactive scripts encounter an error, such as a malformed SQL command or internal meta-com-
mand, processing continues. This has been the traditional behavior of psql but it is sometimes not desirable. If
this variable is set, script processing will immediately terminate. If the script was called from another script
it will terminate in the same fashion. If the outermost script was not called from an interactive psql session but
rather using the -f option, psql will return error code 3, to distinguish this case from fatal error conditions
(error code 1).
PORT The database server port to which you are currently connected. This is set every time you connect to a database
(including program start-up), but can be unset.
PROMPT1
PROMPT2
PROMPT3
These specify what the prompts psql issues should look like. See Prompting [psql(1)] below.
QUIET This variable is equivalent to the command line option -q. It is probably not too useful in interactive mode.
SINGLELINE
This variable is equivalent to the command line option -S.
SINGLESTEP
This variable is equivalent to the command line option -s.
USER The database user you are currently connected as. This is set every time you connect to a database (including pro-
gram start-up), but can be unset.
VERBOSITY
This variable can be set to the values default, verbose, or terse to control the verbosity of error reports.
SQL INTERPOLATION
An additional useful feature of psql variables is that you can substitute (``interpolate'') them into regular SQL state-
ments. The syntax for this is again to prepend the variable name with a colon (:):
testdb=> \set foo 'my_table'
testdb=> SELECT * FROM :foo;
would then query the table my_table. The value of the variable is copied literally, so it can even contain unbalanced
quotes or backslash commands. You must make sure that it makes sense where you put it. Variable interpolation will not be
performed into quoted SQL entities.
One possible 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 proceed as above:
testdb=> \set content '''' `cat my_file.txt` ''''
testdb=> INSERT INTO my_table VALUES (:content);
One problem with this approach is that my_file.txt might contain single quotes. These need to be escaped so that they
don't cause a syntax error when the second line is processed. This could be done with the program sed:
testdb=> \set content '''' `sed -e "s/'/''/g" < my_file.txt` ''''
If you are using non-standard-conforming strings then you'll also need to double backslashes. This is a bit tricky:
testdb=> \set content '''' `sed -e "s/'/''/g" -e 's/\\/\\\\/g' < my_file.txt` ''''
Note the use of different shell quoting conventions so that neither the single quote marks nor the backslashes are spe-
cial to the shell. Backslashes are still special to sed, however, so we need to double them. (Perhaps at one point you
thought it was great that all Unix commands use the same escape character.)
Since colons can legally appear in SQL commands, the following rule applies: the character sequence ``:name'' is not
changed unless ``name'' is the name of a variable that is currently set. In any case you can escape a colon with a back-
slash to protect it from substitution. (The colon syntax for variables is standard SQL for embedded query languages, such
as ECPG. The colon syntax for array slices and type casts are PostgreSQL extensions, hence the conflict.)
PROMPTING
The prompts psql issues can be customized to your preference. The three variables PROMPT1, PROMPT2, and PROMPT3 contain
strings and special escape sequences that describe the appearance of the prompt. Prompt 1 is the normal prompt that is
issued when psql requests a new command. Prompt 2 is issued when more input is expected during command input because the
command was not terminated with a semicolon or a quote was not closed. Prompt 3 is issued when you run an SQL COPY com-
mand and you are expected to type in the row values on the terminal.
The value of the selected prompt variable is printed literally, except where a percent sign (%) is encountered. Depend-
ing on the next character, certain other text is substituted instead. Defined substitutions are:
%M The full host name (with domain name) of the database server, or [local] if the connection is over a Unix domain
socket, or [local:/dir/name], if the Unix domain socket is not at the compiled in default location.
%m The host name of the database server, truncated at the first dot, or [local] if the connection is over a Unix
domain socket.
%> The port number at which the database server is listening.
%n The database session user name. (The expansion of this value might change during a database session as the result
of the command SET SESSION AUTHORIZATION.)
%/ The name of the current database.
%~ Like %/, but the output is ~ (tilde) if the database is your default database.
%# If the session user is a database superuser, then a #, otherwise a >. (The expansion of this value might change
during a database session as the result of the command SET SESSION AUTHORIZATION.)
%R In prompt 1 normally =, but ^ if in single-line mode, and ! if the session is disconnected from the database
(which can happen if \connect fails). In prompt 2 the sequence is replaced by -, *, a single quote, a double
quote, or a dollar sign, depending on whether psql expects more input because the command wasn't terminated yet,
because you are inside a /* ... */ comment, or because you are inside a quoted or dollar-escaped string. In prompt
3 the sequence 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).
%digits
The character with the indicated octal code is substituted.
%:name:
The value of the psql variable name. See the section Variables [psql(1)] 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.
Note: This feature was shamelessly plagiarized from tcsh.
COMMAND-LINE EDITING
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. 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.)
ENVIRONMENT
COLUMNS
If \pset columns is zero, controls the width for the wrapped format and width for determining if wide output
requires the pager.
PAGER If the query results do not fit on the screen, they are piped through this command. Typical values are more or
less. The default is platform-dependent. The use of the pager can be disabled by using the \pset command.
PGDATABASE
PGHOST
PGPORT
PGUSER Default connection parameters (see in the documentation).
PSQL_EDITOR
EDITOR
VISUAL Editor used by the \e command. The variables are examined in the order listed; the first that is set is used.
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 in the
documentation).
FILES
o Before starting up, psql attempts to read and execute commands from the system-wide psqlrc file and the user's
~/.psqlrc file. (On Windows, the user's startup file is named %APPDATA%\postgresql\psqlrc.conf.) See PRE-
FIX/share/psqlrc.sample for information on setting up the system-wide file. It could be used to set up the client or
the server to taste (using the \set and SET commands).
o Both the system-wide psqlrc file and the user's ~/.psqlrc file can be made version-specific by appending a dash and the
PostgreSQL release number, for example ~/.psqlrc-8.4.9. A matching version-specific file will be read in preference to
a non-version-specific file.
o The command-line history is stored in the file ~/.psql_history, or %APPDATA%\postgresql\psql_history on Windows.
NOTES
o In an earlier life psql allowed the first argument of a single-letter backslash command to start directly after the
command, without intervening whitespace. As of PostgreSQL 8.4 this is no longer allowed.
o psql is only guaranteed to work smoothly with servers of the same version. That does not mean other combinations will
fail outright, but subtle and not-so-subtle problems might come up. 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.
NOTES FOR WINDOWS USERS
psql is built as a ``console application''. Since the Windows console windows use a different encoding than the rest of
the system, you must take special care when using 8-bit characters within psql. If psql detects a problematic console
code page, it will warn you at startup. To change the console code page, two things are necessary:
o Set the code page by entering cmd.exe /c chcp 1252. (1252 is a code page that is appropriate for German; replace it
with your value.) If you are using Cygwin, you can put this command in /etc/profile.
o Set the console font to Lucida Console, because the raster font does not work with the ANSI code page.
EXAMPLES
The first example shows how to spread a command over several lines of input. Notice the changing prompt:
testdb=> CREATE TABLE my_table (
testdb(> first integer not null default 0,
testdb(> second text)
testdb-> ;
CREATE TABLE
Now look at the table definition again:
testdb=> \d my_table
Table "my_table"
Attribute | Type | Modifier
-----------+---------+--------------------
first | integer | not null default 0
second | text |
Now we change the prompt to something more interesting:
testdb=> \set PROMPT1 '%n@%m %~%R%# '
peter@localhost testdb=>
Let's assume you have filled the table with data and want to take a look at it:
peter@localhost testdb=> SELECT * FROM my_table;
first | second
-------+--------
1 | one
2 | two
3 | three
4 | four
(4 rows)
You can display tables in different ways by using the \pset command:
peter@localhost testdb=> \pset border 2
Border style is 2.
peter@localhost testdb=> SELECT * FROM my_table;
+-------+--------+
| first | second |
+-------+--------+
| 1 | one |
| 2 | two |
| 3 | three |
| 4 | four |
+-------+--------+
(4 rows)
peter@localhost testdb=> \pset border 0
Border style is 0.
peter@localhost testdb=> SELECT * FROM my_table;
first second
----- ------
1 one
2 two
3 three
4 four
(4 rows)
peter@localhost testdb=> \pset border 1
Border style is 1.
peter@localhost testdb=> \pset format unaligned
Output format is unaligned.
peter@localhost testdb=> \pset fieldsep ","
Field separator is ",".
peter@localhost testdb=> \pset tuples_only
Showing 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 \x
Output format is aligned.
Tuples only is off.
Expanded display is on.
peter@localhost testdb=> SELECT * FROM my_table;
-[ RECORD 1 ]-
first | 1
second | one
-[ RECORD 2 ]-
first | 2
second | two
-[ RECORD 3 ]-
first | 3
second | three
-[ RECORD 4 ]-
first | 4
second | four
Application 2011-09-22 PSQL(1)
