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 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 rather than interactive mode. This is equiva-
              lent 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 specific features), or a single  back-
              slash  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 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 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  fea-
              tures  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 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.

       -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
              Allows  you to specify printing options in the style of \pset on the command line. Note that here you have to separate 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 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 \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 without 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

       –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 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 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 deter-
       mined 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 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.

   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
       Welcome to psql 8.3.3, the PostgreSQL interactive terminal.

       Type:  \copyright for distribution terms
              \h for help with SQL commands
              \? for help with psql commands
              \g or terminate with semicolon to execute query
              \q to quit

       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 [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 argument, use two single quotes. Any-
       thing 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 new-
       line 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 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 when another unquoted backslash occurs.  This 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.

       \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.

       \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 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 pre-
              vious 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, 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 [ pattern ]

       \d+ [ 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.

              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 [ pattern ]
              Lists  all  available aggregate functions, together with their return type and the data types they operate on. If pattern is specified, only aggre-
              gates whose names match the pattern are shown.

       \db [ pattern ]

       \db+ [ pattern ]
              Lists all available tablespaces. If pattern is specified, only tablespaces whose names match the pattern are shown.  If + is appended to  the  com-
              mand name, each object is listed with its associated permissions.

       \dc [ pattern ]
              Lists  all  available  conversions  between  character-set  encodings.  If pattern is specified, only conversions whose names match the pattern are
              listed.

       \dC    Lists all available type casts.

       \dd [ 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.  (”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 [ pattern ]
              Lists all available domains. If pattern is specified, only matching domains are shown.

       \df [ pattern ]

       \df+ [ pattern ]
              Lists available functions, together with their argument and return types. 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.

              Note:

              To look up functions taking argument or returning values of a specific type, use your pager’s search capability to scroll through the \df output.

              To reduce clutter, \df does not show data type I/O functions. This is implemented by ignoring functions that accept or return type cstring.

       \dF [ pattern ]

       \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 ]

       \dFd+ [ pattern ]
              Lists available 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 ]

       \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 ]

       \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.)

       \distvS [ pattern ]
              This is not the actual command name: the letters i, s, t, v, S stand for index, sequence, table, view, and  system  table,  respectively.  You  can
              specify  any  or  all of these letters, in any order, to obtain a listing of all the matching objects. The letter S restricts the listing to system
              objects; without S, only non-system objects are shown. If + is appended to the command name, each object is listed with its associated description,
              if any.

              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 ]

       \dn+ [ pattern ]
              Lists  all  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 [ pattern ]
              Lists available operators with their operand and return types.  If pattern is specified, only operators whose names match the pattern are listed.

       \dp [ pattern ]
              Produces  a list of all 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 [ pattern ]

       \dT+ [ pattern ]
              Lists all data types or only those that match pattern. The command form \dT+ shows extra information.

       \du [ pattern ]
              Lists all database roles, or only those that match pattern.

       \edit (or \e) [ filename ]
              If filename is specified, the file is edited; after the editor exits, its content is copied back to the query buffer. 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.

       \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 avail-
              able. 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, and character set encodings of all the databases in the server. If + is appended to the command name, database descriptions
              are also displayed.

       \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  speci-
              fied, 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 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  stan-
              dard 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, html, latex, or troff-ms.  Unique abbreviations are allowed. (That would mean one  let-
                     ter 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. 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.)

              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 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.

                     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 toggle 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 seperate 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 output is piped to the specified  pro-
                     gram.  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 appropriate, i.e. the output is to a termi-
                     nal and will not fit on the screen.  (psql does not do a perfect job of estimating when to use the pager.) \pset pager turns  the  pager  on
                     and  off.  Pager  can  also be set to always, which causes the pager to be always used, or you can set the pager to on which will enable the
                     usage of the pager when appropriate, or you can set the pager to off which will disable the pager.

       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 command.

              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 conve-
              nience.

       \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 ta-
              ble_options.

       \timing
              Toggles a display of how long each SQL statement takes, in milliseconds.

       \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 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.

              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  exam-
       ple,  \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 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  char-
       acters  work  as  specified  in 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 interpreta-
       tion 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  pat-
       tern  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).

       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 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.

       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 variables 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 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.

       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_insert 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, if non-interactive scripts encounter an error, such as a malformed SQL command or internal meta-command, 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 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
       An additional useful feature of psql variables is that you can substitute (”interpolate”) them into regular SQL statements. 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.

       A popular application of this facility is to refer to the last inserted OID in subsequent statements to build a foreign key scenario. Another 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 special 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 char-
       acter.)

       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 backslash 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  con-
       flict.)

   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 AUTHO-
              RIZATION.)

       %/     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 desig-
              nated 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
       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-depen-
              dent. The use of the pager can be disabled by using the \pset command.

       PGDATABASE
              Default connection database

       PGHOST

       PGPORT

       PGUSER Default connection parameters

       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
       ? 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 PREFIX/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).

       ? 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-8.3.3.  A matching version-specific file will be read in preference to a non-version-specific file.

       ? The command-line history is stored in the file ~/.psql_history, or %APPDATA%\postgresql\psql_history on Windows.

NOTES
       ? In an earlier life psql allowed the first argument of a single-letter backslash command to start directly after the command, without intervening whites-
         pace.  For compatibility this is still supported to some extent, but we are not going to explain the details here as this use is discouraged. If you get
         strange messages, keep this in mind.  For example:

         testdb=> \foo
         Field separator is “oo”.

         which is perhaps not what one would expect.

       ? psql only works smoothly with servers of the same version. That does not mean other combinations will fail outright, but subtle and not-so-subtle  prob-
         lems might come up. Backslash commands are particularly likely to fail if the server is of a different version.

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:

       ? Set  the  code page by entering cmd.exe /c chcp 1252. (1252 is a code page that is appropriate for German; replace it with your value.) If you are using
         Cygwin, you can put this command in /etc/profile.

       ? Set the console font to Lucida Console, because the raster font does not work with the ANSI code page.

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                       2008-06-08                           PSQL(1)

Leave a Reply

Your email address will not be published. Required fields are marked *

clear formPost comment