When you first start psql , you will be greeted with a brief synopsis of four essential psql slash commands: \h for SQL help, \? for help on psql -specific commands, \g for executing queries and \q for actually exiting psql once you are done.

Every psql -specific command is prefixed by a backslash; hence term "slash command" used above. For a complete list of slash commands and a brief description of each of their functions, type \? into the psql command line, and press enter.

Example 4-2. Listing psql Slash Commands

booktown=# \?
 \a             toggle between unaligned and aligned mode
 \c[onnect] [dbname|- [user]]
                connect to new database (currently 'booktown')
 \C <title>     table title
 \copy ...      perform SQL COPY with data stream to the client machine
 \copyright     show PostgreSQL usage and distribution terms
 \d <table>     describe table (or view, index, sequence)
 \d{t|i|s|v}    list tables/indices/sequences/views
 \d{p|S|l}      list permissions/system tables/lobjects
 \da            list aggregates
 \dd [object]   list comment for table, type, function, or operator 
 \df            list functions
  \do            list operators
 \dT            list data types
 \e [file]      edit the current query buffer or [file] with external editor
 \echo <text>   write text to stdout
 \encoding <encoding>  set client encoding
 \f <sep>       change field separator
 \g [file]      send query to backend (and results in [file] or |pipe)
 \h [cmd]       help on syntax of sql commands, * for all commands
 \H             toggle HTML mode (currently off)
 \i <file>      read and execute queries from <file>
 \l             list all databases
 \lo_export, \lo_import, \lo_list, \lo_unlink
                large object operations
 \o [file]      send all query results to [file], or |pipe
 \p             show the content of the current query buffer
 \pset <opt>    set table output  <opt> = {format|border|expanded|fieldsep|
                null|recordsep|tuples_only|title|tableattr|pager}
 \q             quit psql
 \qecho <text>  write text to query output stream (see \o)
 \r             reset (clear) the query buffer
 \s [file]      print history or save it in [file]
 \set <var> <value>  set internal variable
 \t             show only rows (currently off)
 \T <tags>      HTML table tags
 \unset <var>   unset (delete) internal variable
 \w <file>      write current query buffer to a <file>
 \x             toggle expanded output (currently off)
 \z             list table access permissions
 \! [cmd]       shell escape or command
booktown=#