PSQL(1) PostgreSQL 9.2.7 Documentation PSQL(1)
NAME
psql - PostgreSQL interactive terminal
SYNOPSIS
psql [option...] [dbname [username]]
DESCRIPTION
psql is a terminal-based front-end to PostgreSQL. It enables you to type in queries interactively, issue them to PostgreSQL, and see the
query results. Alternatively, input can be from a file. 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 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. Start-up files (psqlrc
and ~/.psqlrc) are ignored with this option.
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 with this option. To achieve that, you could pipe the string
into psql, for example: 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. Also, only the result of the last SQL command is returned.
Because of these legacy behaviors, putting more than one command in the -c string often has unexpected results. It's better to 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.
If this parameter contains an = sign or starts with a valid URI prefix (postgresql:// or postgres://), it is treated as a conninfo
string. See Section 31.1, "Database Connection Control Functions", in the documentation for more information.
-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 processed, psql
terminates. This is in many ways equivalent to the meta-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 redirection is (in theory) guaranteed to yield exactly the same output
you would have received had you entered everything by hand.
-F separator, --field-separator=separator
Use separator as the field separator for unaligned output. This is equivalent to pset fieldsep or f.
-h hostname, --host=hostname
Specifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory
for the Unix-domain socket.
-H, --html
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.
-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 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. 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 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 the command.
-T table_options, --table-attr=table_options
Specifies 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 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 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).
-z, --field-separator-zero
Set the field separator for unaligned output to a zero byte.
-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.
-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 occurs (e.g. out of memory, file not found), 2 if the
connection to the server went bad and the session was not interactive, and 3 if an error occurred in a script and the variable
ON_ERROR_STOP was set.
USAGE
Connecting to a Database
psql is a regular PostgreSQL client application. In order to connect to a database you need to know the name of your target database, the
host name and port number of the server, and what user name you want to connect as. psql can be told about those parameters via command
line options, namely -d, -h, -p, and -U respectively. If an argument is found that does not belong to any option it will be interpreted as
the database name (or the user name, if the database name is already given). Not all of these options are required; there are useful
defaults. If you omit the host name, psql will connect via a Unix-domain socket to a server on the local host, or via TCP/IP to localhost
on machines that don't have Unix-domain sockets. The default port number is determined at compile time. Since the database server uses the
same default, you will not have to specify the port in most cases. The default user name is your 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 Section 31.14, "Environment Variables", in the
documentation.) It is also convenient to have a ~/.pgpass file to avoid regularly having to type in passwords. See Section 31.15, "The
Password File", in the documentation 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 31.17, "LDAP Lookup of Connection Parameters", in
the documentation. See Section 31.1, "Database Connection Control Functions", in the documentation 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 at least one of standard input or standard output are a terminal, then psql sets the client encoding to "auto", which will detect the
appropriate client encoding from the locale settings (LC_CTYPE environment variable on Unix systems). If this doesn't work out as expected,
the client encoding can be overridden using the environment variable PGCLIENTENCODING.
Entering SQL Commands
In normal operation, psql provides a prompt with the name of the database to which psql is currently connected, followed by the string =>.
For example:
$ psql testdb
psql (9.2.7)
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.
Whenever a command is executed, psql also polls for asynchronous notification events generated by LISTEN(7) and 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
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
(new line), (tab),
(backspace),
(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.
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.
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.
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.
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 [ dbname [ username ] [ host ] [ port ] ]
Establishes a new connection to a PostgreSQL server. If the new connection is successfully made, the previous connection 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.
C [ title ]
Sets the title of any tables being printed as the result of a query or unset any such title. This command is equivalent to pset title
title. (The name of this command derives from "caption", as it was previously only used to set the caption in an HTML table.)
cd [ directory ]
Changes the current working directory to directory. Without argument, changes to the current user's home directory.
Tip
To print your current working directory, use ! pwd.
conninfo
Outputs information about the current database connection.
copy { table [ ( column_list ) ] | ( query ) } { from | to } { filename | stdin | stdout | pstdin | pstdout } [ with ] [ binary ] [ oids ]
[ delimiter [ as ] 'character' ] [ null [ as ] 'string' ] [ csv [ header ] [ quote [ as ] 'character' ] [ escape [ as ] 'character' ] [
force quote column_list | * ] [ force not null column_list ] ]
Performs a frontend (client) copy. This is an operation that runs an SQL 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(7) command. Note that, because of this, special 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, 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 expression 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.
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 dtvsE which will show a list of all visible tables, 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.
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 object is listed with its associated permissions.
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(7) SQL command.
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 (ALTER_DEFAULT_PRIVILEGES(7)) command is used to set default access privileges. The meaning of the
privilege display is explained under GRANT(7).
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.
dE[S+] [ pattern ], di[S+] [ pattern ], ds[S+] [ pattern ], dt[S+] [ pattern ], dv[S+] [ pattern ]
In this group of commands, the letters E, i, s, t, and v stand for foreign table, index, 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.
Caution
deu+ might also display the user name and password of the remote user, so care should be taken not to disclose them.
dew[+] [ pattern ]
Lists foreign-data wrappers (mnemonic: "external wrappers"). If pattern is specified, only those foreign-data wrappers whose name
matches the pattern are listed. If the form dew+ is used, the ACL, options, and description of the foreign-data wrapper are also
shown.
df[antwS+] [ pattern ]
Lists functions, together with their arguments, return types, and function types, which are classified as "agg" (aggregate), "normal",
"trigger", or "window". To display only functions of specific type(s), add the corresponding letters a, n, t, or w to the command. 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 description, is shown. By default, only user-created objects are shown;
supply a pattern or the S modifier to include system objects.
Tip
To look up functions taking arguments or returning values of a specific 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[+] [ pattern ]
Lists database roles. (Since the concepts of "users" and "groups" have been unified into "roles", this command is now equivalent to
du.) 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 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.
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(7) and REVOKE(7) commands are used to set access privileges. The meaning of the privilege display is explained under
GRANT(7).
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 (ALTER_ROLE(7)) and ALTER DATABASE (ALTER_DATABASE(7)) commands are used to define per-role and per-database
configuration settings.
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[+] [ pattern ]
Lists database roles. (Since the concepts of "users" and "groups" have been unified into "roles", this command is now equivalent to
dg.) 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.
e or edit [ filename ] [ line_number ]
If filename is specified, the file is edited; after the editor exits, its content is copied back to the 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.
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 that if the query ends with (or contains) a semicolon, it is immediately
executed. Otherwise it will merely wait in the query buffer; type semicolon or g to send it, or
to cancel.
If a line number is specified, psql will position the cursor on the specified line of the file or query buffer. Note that if a single
all-digits argument is given, psql assumes it is a line number, not a file name.
Tip
See 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.
Tip
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, in the form of a CREATE OR REPLACE FUNCTION 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
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.)
Tip
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.
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.
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.
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.
ir 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), 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 different from the server
function lo_export, which acts with the permissions of the user that the database server runs as and on the server's file system.
Tip
Use lo_list to find out the large object's OID.
lo_import filename [ comment ]
Stores the file into a PostgreSQL large object. Optionally, it associates the given comment with the object. Example:
foo=> lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'
lo_import 152801
The response indicates that the large object received object ID 152801, which can be used to access the newly-created large object in
the future. For the sake of readability, it is recommended to always associate a human-readable comment with every object. Both OIDs
and comments can be viewed with the lo_list command.
Note that this command is subtly different from the server-side lo_import because it acts as the local user on the local file system,
rather than the server's user and file system.
lo_list
Shows a list of all PostgreSQL large objects currently stored in the database, along with any comments provided for them.
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 command. 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 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.
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 this depends on
the particular format. In HTML format, this will translate directly into the border=... attribute; in the other formats only
values 0 (no border), 1 (internal dividing lines), and 2 (table frame) make sense.
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 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 ' '. The default field separator
is '|' (a vertical bar).
fieldsep_zero
Sets the field separator to use in unaligned output format to a zero byte.
footer
If value is specified it must be either on or off which will enable or disable display of the table footer (the (n rows) count). If
value is omitted the command toggles footer display on or off.
format
Sets the output format to one of unaligned, aligned, wrapped, html, latex, or troff-ms. Unique abbreviations are allowed. (That
would mean one letter is enough.)
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, latex, 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 so dramatic in HTML, but in LaTeX you must have a complete document
wrapper.)
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, this 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 PAGER is set, the output is piped to
the specified program. Otherwise a platform-dependent default (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.
recordsep
Specifies the record (line) separator to use in unaligned output format. The default is a newline character.
recordsep_zero
Sets the record separator to use in unaligned output format to a zero byte.
tableattr (or T)
Specifies attributes to be placed inside the HTML table tag in html output format. 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.
title
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.
Illustrations of how these different formats look can be seen in the EXAMPLES section.
Tip
There are various shortcut commands for pset. See a, C, H, , T, and x.
Note
It is an error to call pset without any arguments. In the future this case might show the current status of all printing options.
q or quit
Quits the psql program. In a script file, only execution of that script is terminated.
qecho text [ ... ]
This command is identical to echo except that the output will be written to the query output channel, as set by o.
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 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 with an empty 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.
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 unrelated to the SQL command SET(7).
setenv [ name [ value ] ]
Sets the environment variable name to value, or if the value is not supplied, unsets the environment variable. Example:
testdb=> setenv PAGER less
testdb=> setenv LESS -imx4F
sf[+] function_description
This command fetches and shows the definition of the named function, in the form of a CREATE OR REPLACE FUNCTION 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.
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.
iming [ on | off ]
Without parameter, toggles a display of how long each SQL statement takes, in milliseconds. With parameter, sets same.
unset name
Unsets (deletes) the psql variable name.
w filename, w |command
Outputs the current query buffer to the file filename or pipes it to the Unix command command.
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 ]
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 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, "POSIX Regular Expressions", in the documentation, except for .
which is taken as a separator as mentioned above, * which is translated to the regular-expression notation .*, ? which is translated
to ., and $ which is matched literally. You can emulate these pattern characters at need by writing ? for ., (R+|) for R*, or (R|) for
R?. $ is not needed as a regular-expression character since the pattern must match the whole name, unlike the usual interpretation of
regular expressions (in other words, $ is automatically appended to your pattern). Write * at the beginning and/or end if you don't
wish the pattern to be anchored. Note that within double quotes, all regular expression special characters lose their special meanings
and are matched literally. Also, the regular expression special characters are matched literally in operator name patterns (i.e., the
argument of do).
Advanced Features
Variables
psql provides variable substitution features similar to common Unix command shells. Variables are simply name/value pairs, where the
value can be any string of any length. The name must consist of letters (including non-Latin letters), digits, and underscores.
To set a variable, use the psql meta-command set. For example,
testdb=> set foo bar
sets the variable foo to the value bar. To retrieve the content of the variable, precede the name with a colon, for example:
testdb=> echo :foo
bar
This works in both regular SQL commands and meta-commands; there is more detail in SQL Interpolation, below.
If you call set without a second argument, the variable is set, with an empty string as value. To unset (i.e., delete) a variable, use
the command unset. To show the values of all variables, call set without any argument.
Note
The arguments of set are subject to the same substitution rules as with other commands. Thus you can construct interesting
references such as set :foo 'something' and get "soft links" or "variable variables" of Perl or PHP fame, respectively.
Unfortunately (or fortunately?), there is no way to do anything useful with these constructs. On the other hand, set bar :foo is a
perfectly valid way to copy a variable.
A number of these variables are treated specially by psql. They represent certain option settings that can be changed at run time by
altering the value of the variable, or in some cases represent changeable state of psql. Although you can use these variables for other
purposes, this is not recommended, as the program behavior might grow really strange really quickly. 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. A list of all specially 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 transaction-control command, nor a command that cannot be executed inside a
transaction block (such as VACUUM).
Note
In autocommit-off mode, you must explicitly abandon any failed transaction by entering ABORT or ROLLBACK. Also keep in mind
that if you exit the session without committing, your work will be lost.
Note
The autocommit-on mode is PostgreSQL's traditional behavior, but autocommit-off is closer to the SQL spec. If you prefer
autocommit-off, you might wish to set it in the system-wide psqlrc file or your ~/.psqlrc file.
COMP_KEYWORD_CASE
Determines which letter case to use when completing an SQL key word. If set to lower or upper, the completed word will be in lower
or upper case, respectively. If set to preserve-lower or preserve-upper (the default), the completed word will be in the case of
the word already entered, but words being completed without anything entered will be in lower or upper case, respectively.
DBNAME
The name of the database you are currently connected to. This is set every time you connect to a database (including program
start-up), but can be 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 combines 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 (including 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 application. 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_import command. This variable is only guaranteed 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 continues. 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, command processing continues after an error. When this variable is set, it will instead stop immediately. In
interactive mode, psql will return to the command prompt; otherwise, psql will exit, returning error code 3 to distinguish this
case from fatal error conditions, which are reported using error code 1. In either case, any currently running scripts (the
top-level script, if any, and any other scripts which it may have in invoked) will be terminated immediately. If the top-level
command string contained multiple SQL commands, processing will stop with the current command.
PORT
The database server port to which you are currently connected. This is set every time you connect to a database (including program
start-up), but can be unset.
PROMPT1, PROMPT2, PROMPT3
These specify what the prompts psql issues should look like. See Prompting 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 program 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
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 colon syntax for variables is standard SQL for embedded query languages, such as ECPG. The colon syntaxes for array slices and type
casts are PostgreSQL extensions, which can sometimes conflict with the standard usage. The colon-quote syntax for escaping a variable's
value as an SQL literal or identifier is a psql extension.
Prompting
The prompts psql issues can be customized to your preference. The three variables PROMPT1, PROMPT2, and PROMPT3 contain strings and
special escape sequences that describe the appearance of the prompt. Prompt 1 is the normal prompt that is issued when psql requests a
new command. Prompt 2 is issued when more input is expected during command 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 command 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. Depending on the next
character, certain other text is substituted instead. Defined substitutions are:
%M
The full host name (with domain name) of the database server, or [local] if the connection is over a Unix domain socket, or
[local:/dir/name], if the Unix domain socket is not at the compiled in default location.
%m
The host name of the database server, truncated at the first dot, or [local] if the connection is over a Unix domain socket.
%>
The port number at which the database server is listening.
%n
The database session user name. (The expansion of this value might change during a database session as the result of the command
SET SESSION AUTHORIZATION.)
%/
The name of the current database.
%~
Like %/, but the output is ~ (tilde) if the database is your default database.
%#
If the session user is a database superuser, then a #, otherwise a >. (The expansion of this value might change during a database
session as the result of the command SET SESSION AUTHORIZATION.)
%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 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 or
should be switched to the vertical format in expanded auto mode.
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 Section 31.14, "Environment Variables", in the documentation).
PSQL_EDITOR, EDITOR, VISUAL
Editor used by the e and ef commands. The variables are examined in the order listed; the first that is set is used.
The built-in default editors are vi on Unix systems and notepad.exe on Windows systems.
PSQL_EDITOR_LINENUMBER_ARG
When e or ef 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.
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 31.14, "Environment
Variables", in the documentation).
FILES
psqlrc and ~/.psqlrc
Unless it is passed an -X or -c 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%postgresqlpsqlrc.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%postgresqlpsql_history on Windows.
The location of the history file can be set explicitly via the PSQL_HISTORY environment variable.
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 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
PostgreSQL 9.2.7 2014-02-17 PSQL(1)