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>PostgreSQL 8.3.6 Documentation</TH
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><H1
><A
NAME="APP-PSQL"
></A
><SPAN
CLASS="APPLICATION"
>psql</SPAN
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN64147"
></A
><H2
>Name</H2
><SPAN
CLASS="APPLICATION"
>psql</SPAN
> -- <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> interactive terminal
</DIV
><A
NAME="AEN64152"
></A
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN64154"
></A
><H2
>Synopsis</H2
><P
><TT
CLASS="COMMAND"
>psql</TT
> [<TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
>...] [<TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
>
[<TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
>]]</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN64163"
></A
><H2
>Description</H2
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> is a terminal-based front-end to
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>. It enables you to type in
queries interactively, issue them to
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>, 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.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="R1-APP-PSQL-3"
></A
><H2
>Options</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-a</TT
><BR><TT
CLASS="OPTION"
>--echo-all</TT
></DT
><DD
><P
> Print all input lines to standard output as they are read. This is more
useful for script processing rather than interactive mode. This is
equivalent to setting the variable <TT
CLASS="VARNAME"
>ECHO</TT
> to
<TT
CLASS="LITERAL"
>all</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-A</TT
><BR><TT
CLASS="OPTION"
>--no-align</TT
></DT
><DD
><P
> Switches to unaligned output mode. (The default output mode is
otherwise aligned.)
</P
></DD
><DT
><TT
CLASS="OPTION"
>-c <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--command <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
></TT
></DT
><DD
><P
> Specifies that <SPAN
CLASS="APPLICATION"
>psql</SPAN
> is to execute one
command string, <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>,
and then exit. This is useful in shell scripts.
</P
><P
> <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
> must be either
a command string that is completely parsable by the server (i.e.,
it contains no <SPAN
CLASS="APPLICATION"
>psql</SPAN
> specific features),
or a single backslash command. Thus you cannot mix
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> and <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
meta-commands with this option. To achieve that, you could
pipe the string into <SPAN
CLASS="APPLICATION"
>psql</SPAN
>, like
this: <TT
CLASS="LITERAL"
>echo '\x \\ SELECT * FROM foo;' | psql</TT
>.
(<TT
CLASS="LITERAL"
>\\</TT
> is the separator meta-command.)
</P
><P
> If the command string contains multiple SQL commands, they are
processed in a single transaction, unless there are explicit
<TT
CLASS="COMMAND"
>BEGIN</TT
>/<TT
CLASS="COMMAND"
>COMMIT</TT
> commands included in the
string to divide it into multiple transactions. This is
different from the behavior when the same string is fed to
<SPAN
CLASS="APPLICATION"
>psql</SPAN
>'s standard input.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-d <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--dbname <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
></TT
></DT
><DD
><P
> Specifies the name of the database to connect to. This is
equivalent to specifying <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
> as the first non-option
argument on the command line.
</P
><P
> If this parameter contains an <TT
CLASS="SYMBOL"
>=</TT
> sign, it is treated as a
<TT
CLASS="PARAMETER"
>conninfo</TT
> string. See <A
HREF="libpq-connect.html"
>Section 30.1</A
> for more information.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-e</TT
><BR><TT
CLASS="OPTION"
>--echo-queries</TT
></DT
><DD
><P
> Copy all SQL commands sent to the server to standard output as well.
This is equivalent
to setting the variable <TT
CLASS="VARNAME"
>ECHO</TT
> to
<TT
CLASS="LITERAL"
>queries</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-E</TT
><BR><TT
CLASS="OPTION"
>--echo-hidden</TT
></DT
><DD
><P
> Echo the actual queries generated by <TT
CLASS="COMMAND"
>\d</TT
> and other backslash
commands. You can use this to study <SPAN
CLASS="APPLICATION"
>psql</SPAN
>'s
internal operations. This is equivalent to
setting the variable <TT
CLASS="VARNAME"
>ECHO_HIDDEN</TT
> from within
<SPAN
CLASS="APPLICATION"
>psql</SPAN
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-f <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
></DT
><DD
><P
> Use the file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>
as the source of commands instead of reading commands interactively.
After the file is processed, <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
terminates. This is in many ways equivalent to the internal
command <TT
CLASS="COMMAND"
>\i</TT
>.
</P
><P
> If <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> is <TT
CLASS="LITERAL"
>-</TT
>
(hyphen), then standard input is read.
</P
><P
> Using this option is subtly different from writing <TT
CLASS="LITERAL"
>psql
< <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
>. In general,
both will do what you expect, but using <TT
CLASS="LITERAL"
>-f</TT
>
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 that you would have gotten had you entered
everything by hand.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-F <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--field-separator <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
></TT
></DT
><DD
><P
> Use <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
> as the
field separator for unaligned output. This is equivalent to
<TT
CLASS="COMMAND"
>\pset fieldsep</TT
> or <TT
CLASS="COMMAND"
>\f</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-h <TT
CLASS="REPLACEABLE"
><I
>hostname</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--host <TT
CLASS="REPLACEABLE"
><I
>hostname</I
></TT
></TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-H</TT
><BR><TT
CLASS="OPTION"
>--html</TT
></DT
><DD
><P
> Turn on <ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> tabular output. This is
equivalent to <TT
CLASS="LITERAL"
>\pset format html</TT
> or the
<TT
CLASS="COMMAND"
>\H</TT
> command.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-l</TT
><BR><TT
CLASS="OPTION"
>--list</TT
></DT
><DD
><P
> List all available databases, then exit. Other non-connection
options are ignored. This is similar to the internal command
<TT
CLASS="COMMAND"
>\list</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-L <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--log-file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
></DT
><DD
><P
> Write all query output into file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>, in addition to the
normal output destination.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-o <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--output <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
></DT
><DD
><P
> Put all query output into file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>. This is equivalent to
the command <TT
CLASS="COMMAND"
>\o</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-p <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--port <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
></TT
></DT
><DD
><P
> 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 <TT
CLASS="ENVAR"
>PGPORT</TT
>
environment variable or, if not set, to the port specified at
compile time, usually 5432.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-P <TT
CLASS="REPLACEABLE"
><I
>assignment</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--pset <TT
CLASS="REPLACEABLE"
><I
>assignment</I
></TT
></TT
></DT
><DD
><P
> Allows you to specify printing options in the style of
<TT
CLASS="COMMAND"
>\pset</TT
> 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
<TT
CLASS="LITERAL"
>-P format=latex</TT
>.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-q</TT
><BR><TT
CLASS="OPTION"
>--quiet</TT
></DT
><DD
><P
> Specifies that <SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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 <TT
CLASS="OPTION"
>-c</TT
> option.
Within <SPAN
CLASS="APPLICATION"
>psql</SPAN
> you can also set the
<TT
CLASS="VARNAME"
>QUIET</TT
> variable to achieve the same effect.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-R <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--record-separator <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
></TT
></DT
><DD
><P
> Use <TT
CLASS="REPLACEABLE"
><I
>separator</I
></TT
> as the
record separator for unaligned output. This is equivalent to the
<TT
CLASS="COMMAND"
>\pset recordsep</TT
> command.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-s</TT
><BR><TT
CLASS="OPTION"
>--single-step</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-S</TT
><BR><TT
CLASS="OPTION"
>--single-line</TT
></DT
><DD
><P
> Runs in single-line mode where a newline terminates an SQL command, as a
semicolon does.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This mode is provided for those who insist on it, but you are not
necessarily encouraged to use it. In particular, if you mix
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> and meta-commands on a line the order of
execution might not always be clear to the inexperienced user.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="OPTION"
>-t</TT
><BR><TT
CLASS="OPTION"
>--tuples-only</TT
></DT
><DD
><P
> Turn off printing of column names and result row count footers,
etc. This is equivalent to the <TT
CLASS="COMMAND"
>\t</TT
> command.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-T <TT
CLASS="REPLACEABLE"
><I
>table_options</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--table-attr <TT
CLASS="REPLACEABLE"
><I
>table_options</I
></TT
></TT
></DT
><DD
><P
> Allows you to specify options to be placed within the
<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> <CODE
CLASS="SGMLTAG"
>table</CODE
> tag. See
<TT
CLASS="COMMAND"
>\pset</TT
> for details.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-U <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--username <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
></TT
></DT
><DD
><P
> Connect to the database as the user <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
> instead of the default.
(You must have permission to do so, of course.)
</P
></DD
><DT
><TT
CLASS="OPTION"
>-v <TT
CLASS="REPLACEABLE"
><I
>assignment</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--set <TT
CLASS="REPLACEABLE"
><I
>assignment</I
></TT
></TT
><BR><TT
CLASS="OPTION"
>--variable <TT
CLASS="REPLACEABLE"
><I
>assignment</I
></TT
></TT
></DT
><DD
><P
> Perform a variable assignment, like the <TT
CLASS="COMMAND"
>\set</TT
>
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.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-V</TT
><BR><TT
CLASS="OPTION"
>--version</TT
></DT
><DD
><P
> Print the <SPAN
CLASS="APPLICATION"
>psql</SPAN
> version and exit.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-W</TT
><BR><TT
CLASS="OPTION"
>--password</TT
></DT
><DD
><P
> Force <SPAN
CLASS="APPLICATION"
>psql</SPAN
> to prompt for a
password before connecting to a database.
</P
><P
> This option is never essential, since <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
will automatically prompt for a password if the server demands
password authentication. However, <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
will waste a connection attempt finding out that the server wants a
password. In some cases it is worth typing <TT
CLASS="OPTION"
>-W</TT
> to avoid
the extra connection attempt.
</P
><P
> Note that this option will remain set for the entire session,
and so it affects uses of the meta-command
<TT
CLASS="COMMAND"
>\connect</TT
> as well as the initial connection attempt.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-x</TT
><BR><TT
CLASS="OPTION"
>--expanded</TT
></DT
><DD
><P
> Turn on the expanded table formatting mode. This is equivalent to the
<TT
CLASS="COMMAND"
>\x</TT
> command.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-X,</TT
><BR><TT
CLASS="OPTION"
>--no-psqlrc</TT
></DT
><DD
><P
> Do not read the start-up file (neither the system-wide
<TT
CLASS="FILENAME"
>psqlrc</TT
> file nor the user's
<TT
CLASS="FILENAME"
>~/.psqlrc</TT
> file).
</P
></DD
><DT
><TT
CLASS="OPTION"
>-1</TT
><BR><TT
CLASS="OPTION"
>--single-transaction</TT
></DT
><DD
><P
> When <SPAN
CLASS="APPLICATION"
>psql</SPAN
> executes a script with the
<TT
CLASS="OPTION"
>-f</TT
> option, adding this option wraps
<TT
CLASS="COMMAND"
>BEGIN</TT
>/<TT
CLASS="COMMAND"
>COMMIT</TT
> around the script to execute it
as a single transaction. This ensures that either all the commands
complete successfully, or no changes are applied.
</P
><P
> If the script itself uses <TT
CLASS="COMMAND"
>BEGIN</TT
>, <TT
CLASS="COMMAND"
>COMMIT</TT
>,
or <TT
CLASS="COMMAND"
>ROLLBACK</TT
>, 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.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-?</TT
><BR><TT
CLASS="OPTION"
>--help</TT
></DT
><DD
><P
> Show help about <SPAN
CLASS="APPLICATION"
>psql</SPAN
> command line
arguments, and exit.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN64489"
></A
><H2
>Exit Status</H2
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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 <TT
CLASS="VARNAME"
>ON_ERROR_STOP</TT
> was set.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN64494"
></A
><H2
>Usage</H2
><DIV
CLASS="REFSECT2"
><A
NAME="R2-APP-PSQL-CONNECTING"
></A
><H3
>Connecting To A Database</H3
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> is a regular
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> 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. <SPAN
CLASS="APPLICATION"
>psql</SPAN
> can be
told about those parameters via command line options, namely
<TT
CLASS="OPTION"
>-d</TT
>, <TT
CLASS="OPTION"
>-h</TT
>, <TT
CLASS="OPTION"
>-p</TT
>, and
<TT
CLASS="OPTION"
>-U</TT
> 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, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> will connect via a Unix-domain socket
to a server on the local host, or via TCP/IP to <TT
CLASS="LITERAL"
>localhost</TT
> 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.
</P
><P
> When the defaults aren't quite right, you can save yourself
some typing by setting the environment variables
<TT
CLASS="ENVAR"
>PGDATABASE</TT
>, <TT
CLASS="ENVAR"
>PGHOST</TT
>,
<TT
CLASS="ENVAR"
>PGPORT</TT
> and/or <TT
CLASS="ENVAR"
>PGUSER</TT
> to appropriate
values. (For additional environment variables, see <A
HREF="libpq-envars.html"
>Section 30.12</A
>.) It is also convenient to have a
<TT
CLASS="FILENAME"
>~/.pgpass</TT
> file to avoid regularly having to type in
passwords. See <A
HREF="libpq-pgpass.html"
>Section 30.13</A
> for more information.
</P
><P
> An alternative way to specify connection parameters is in a
<TT
CLASS="PARAMETER"
>conninfo</TT
> string, which is used instead of a
database name. This mechanism give you very wide control over the
connection. For example:
</P><PRE
CLASS="PROGRAMLISTING"
>$ <KBD
CLASS="USERINPUT"
>psql "service=myservice sslmode=require"</KBD
></PRE
><P>
This way you can also use LDAP for connection parameter lookup as
described in <A
HREF="libpq-ldap.html"
>Section 30.15</A
>.
See <A
HREF="libpq-connect.html"
>Section 30.1</A
> for more information on all the
available connection options.
</P
><P
> If the connection could not be made for any reason (e.g., insufficient
privileges, server is not running on the targeted host, etc.),
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> will return an error and terminate.
</P
></DIV
><DIV
CLASS="REFSECT2"
><A
NAME="R2-APP-PSQL-4"
></A
><H3
>Entering SQL Commands</H3
><P
> In normal operation, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> provides a
prompt with the name of the database to which
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> is currently connected, followed by
the string <TT
CLASS="LITERAL"
>=></TT
>. For example:
</P><PRE
CLASS="PROGRAMLISTING"
>$ <KBD
CLASS="USERINPUT"
>psql testdb</KBD
>
Welcome to psql 8.3.6, 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=></PRE
><P>
</P
><P
> At the prompt, the user can type in <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> 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.
</P
><P
> Whenever a command is executed, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> also polls
for asynchronous notification events generated by
<A
HREF="sql-listen.html"
><I
>LISTEN</I
></A
> and
<A
HREF="sql-notify.html"
><I
>NOTIFY</I
></A
>.
</P
></DIV
><DIV
CLASS="REFSECT2"
><A
NAME="AEN64538"
></A
><H3
>Meta-Commands</H3
><P
> Anything you enter in <SPAN
CLASS="APPLICATION"
>psql</SPAN
> that begins
with an unquoted backslash is a <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
meta-command that is processed by <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
itself. These commands help make
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> more useful for administration or
scripting. Meta-commands are more commonly called slash or backslash
commands.
</P
><P
> The format of a <SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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.
</P
><P
> 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. Anything contained in single quotes is
furthermore subject to C-like substitutions for
<TT
CLASS="LITERAL"
>\n</TT
> (new line), <TT
CLASS="LITERAL"
>\t</TT
> (tab),
<TT
CLASS="LITERAL"
>\</TT
><TT
CLASS="REPLACEABLE"
><I
>digits</I
></TT
> (octal), and
<TT
CLASS="LITERAL"
>\x</TT
><TT
CLASS="REPLACEABLE"
><I
>digits</I
></TT
> (hexadecimal).
</P
><P
> If an unquoted argument begins with a colon (<TT
CLASS="LITERAL"
>:</TT
>),
it is taken as a <SPAN
CLASS="APPLICATION"
>psql</SPAN
> variable and the value of the
variable is used as the argument instead.
</P
><P
> Arguments that are enclosed in backquotes (<TT
CLASS="LITERAL"
>`</TT
>)
are taken as a command line that is passed to the shell. The
output of the command (with any trailing newline removed) is taken
as the argument value. The above escape sequences also apply in
backquotes.
</P
><P
> Some commands take an <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> identifier (such as a
table name) as argument. These arguments follow the syntax rules
of <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>: Unquoted letters are forced to
lowercase, while double quotes (<TT
CLASS="LITERAL"
>"</TT
>) 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,
<TT
CLASS="LITERAL"
>FOO"BAR"BAZ</TT
> is interpreted as <TT
CLASS="LITERAL"
>fooBARbaz</TT
>,
and <TT
CLASS="LITERAL"
>"A weird"" name"</TT
> becomes <TT
CLASS="LITERAL"
>A weird"
name</TT
>.
</P
><P
> Parsing for arguments stops when another unquoted backslash occurs.
This is taken as the beginning of a new meta-command. The special
sequence <TT
CLASS="LITERAL"
>\\</TT
> (two backslashes) marks the end of
arguments and continues parsing <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> commands, if
any. That way <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> and
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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.
</P
><P
> The following meta-commands are defined:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>\a</TT
></DT
><DD
><P
> 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 <TT
CLASS="COMMAND"
>\pset</TT
> for a
more general solution.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\cd [ <TT
CLASS="REPLACEABLE"
><I
>directory</I
></TT
> ]</TT
></DT
><DD
><P
> Changes the current working directory to
<TT
CLASS="REPLACEABLE"
><I
>directory</I
></TT
>. Without argument, changes
to the current user's home directory.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> To print your current working directory, use <TT
CLASS="LITERAL"
>\!pwd</TT
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\C [ <TT
CLASS="REPLACEABLE"
><I
>title</I
></TT
> ]</TT
></DT
><DD
><P
> Sets the title of any tables being printed as the result of a
query or unset any such title. This command is equivalent to
<TT
CLASS="LITERAL"
>\pset title <TT
CLASS="REPLACEABLE"
><I
>title</I
></TT
></TT
>. (The name of
this command derives from <SPAN
CLASS="QUOTE"
>"caption"</SPAN
>, as it was
previously only used to set the caption in an
<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> table.)
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\connect</TT
> (or <TT
CLASS="LITERAL"
>\c</TT
>) <TT
CLASS="LITERAL"
>[ <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
> [ <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
> ] [ <TT
CLASS="REPLACEABLE"
><I
>host</I
></TT
> ] [ <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
> ] ]</TT
></DT
><DD
><P
> Establishes a new connection to a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
server. If the new connection is successfully made, the
previous connection is closed. If any of <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
>, <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
>, <TT
CLASS="REPLACEABLE"
><I
>host</I
></TT
> or <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
> are omitted or specified
as <TT
CLASS="LITERAL"
>-</TT
>, the value of that parameter from the
previous connection is used. If there is no previous
connection, the <SPAN
CLASS="APPLICATION"
>libpq</SPAN
> default for
the parameter's value is used.
</P
><P
> If the connection attempt failed (wrong user name, access
denied, etc.), the previous connection will only be kept if
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\copy { <TT
CLASS="REPLACEABLE"
><I
>table</I
></TT
> [ ( <TT
CLASS="REPLACEABLE"
><I
>column_list</I
></TT
> ) ] | ( <TT
CLASS="REPLACEABLE"
><I
>query</I
></TT
> ) }
{ <TT
CLASS="LITERAL"
>from</TT
> | <TT
CLASS="LITERAL"
>to</TT
> }
{ <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> | stdin | stdout | pstdin | pstdout }
[ with ]
[ binary ]
[ oids ]
[ delimiter [ as ] '<TT
CLASS="REPLACEABLE"
><I
>character</I
></TT
>' ]
[ null [ as ] '<TT
CLASS="REPLACEABLE"
><I
>string</I
></TT
>' ]
[ csv
[ header ]
[ quote [ as ] '<TT
CLASS="REPLACEABLE"
><I
>character</I
></TT
>' ]
[ escape [ as ] '<TT
CLASS="REPLACEABLE"
><I
>character</I
></TT
>' ]
[ force quote <TT
CLASS="REPLACEABLE"
><I
>column_list</I
></TT
> ]
[ force not null <TT
CLASS="REPLACEABLE"
><I
>column_list</I
></TT
> ] ]</TT
></DT
><DD
><P
> Performs a frontend (client) copy. This is an operation that
runs an <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> <A
HREF="sql-copy.html"
><I
>COPY</I
></A
> command, but instead of the server
reading or writing the specified file,
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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.
</P
><P
> The syntax of the command is similar to that of the
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> <A
HREF="sql-copy.html"
><I
>COPY</I
></A
> command. Note that, because of this,
special parsing rules apply to the <TT
CLASS="COMMAND"
>\copy</TT
>
command. In particular, the variable substitution rules and
backslash escapes do not apply.
</P
><P
> <TT
CLASS="LITERAL"
>\copy ... from stdin | to stdout</TT
>
reads/writes based on the command input and output respectively.
All rows are read from the same source that issued the command,
continuing until <TT
CLASS="LITERAL"
>\.</TT
> is read or the stream
reaches <ACRONYM
CLASS="ACRONYM"
>EOF</ACRONYM
>. Output is sent to the same place as
command output. To read/write from
<SPAN
CLASS="APPLICATION"
>psql</SPAN
>'s standard input or output, use
<TT
CLASS="LITERAL"
>pstdin</TT
> or <TT
CLASS="LITERAL"
>pstdout</TT
>. This option is useful
for populating tables in-line within a SQL script file.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> This operation is not as efficient as the <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
<TT
CLASS="COMMAND"
>COPY</TT
> command because all data must pass
through the client/server connection. For large
amounts of data the <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> command might be preferable.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\copyright</TT
></DT
><DD
><P
> Shows the copyright and distribution terms of
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\d [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\d+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> For each relation (table, view, index, or sequence) matching the
<TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>, show all
columns, their types, the tablespace (if not the default) and any special
attributes such as <TT
CLASS="LITERAL"
>NOT NULL</TT
> or defaults, if
any. Associated indexes, constraints, rules, and triggers are
also shown, as is the view definition if the relation is a view.
(<SPAN
CLASS="QUOTE"
>"Matching the pattern"</SPAN
> is defined below.)
</P
><P
> The command form <TT
CLASS="LITERAL"
>\d+</TT
> 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.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> If <TT
CLASS="COMMAND"
>\d</TT
> is used without a
<TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> argument, it is
equivalent to <TT
CLASS="COMMAND"
>\dtvs</TT
> which will show a list of
all tables, views, and sequences. This is purely a convenience
measure.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\da [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all available aggregate functions, together with their
return type and the data types they operate on. If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>
is specified, only aggregates whose names match the pattern are shown.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\db [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\db+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all available tablespaces. If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>
is specified, only tablespaces whose names match the pattern are shown.
If <TT
CLASS="LITERAL"
>+</TT
> is appended to the command name, each object
is listed with its associated permissions.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dc [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all available conversions between character-set encodings.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>
is specified, only conversions whose names match the pattern are
listed.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dC</TT
></DT
><DD
><P
> Lists all available type casts.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dd [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Shows the descriptions of objects matching the <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>, or of all visible objects if
no argument is given. But in either case, only objects that have
a description are listed.
(<SPAN
CLASS="QUOTE"
>"Object"</SPAN
> covers aggregates, functions, operators,
types, relations (tables, views, indexes, sequences, large
objects), rules, and triggers.) For example:
</P><PRE
CLASS="PROGRAMLISTING"
>=> <KBD
CLASS="USERINPUT"
>\dd version</KBD
>
Object descriptions
Schema | Name | Object | Description
------------+---------+----------+---------------------------
pg_catalog | version | function | PostgreSQL version string
(1 row)</PRE
><P>
</P
><P
> Descriptions for objects can be created with the <A
HREF="sql-comment.html"
><I
>COMMENT</I
></A
>
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> command.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dD [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all available domains. If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>
is specified, only matching domains are shown.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\df [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\df+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available functions, together with their argument and
return types. If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>
is specified, only functions whose names match the pattern are shown.
If the form <TT
CLASS="LITERAL"
>\df+</TT
> is used, additional information about
each function, including volatility, language, source code and description, is shown.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> To look up functions taking argument or returning values of a specific
type, use your pager's search capability to scroll through the <TT
CLASS="LITERAL"
>\df</TT
>
output.
</P
><P
> To reduce clutter, <TT
CLASS="LITERAL"
>\df</TT
> does not show data type I/O
functions. This is implemented by ignoring functions that accept
or return type <TT
CLASS="TYPE"
>cstring</TT
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\dF [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dF+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available text search configurations.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is specified,
only configurations whose names match the pattern are shown.
If the form <TT
CLASS="LITERAL"
>\dF+</TT
> 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.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dFd [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dFd+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available text search dictionaries.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is specified,
only dictionaries whose names match the pattern are shown.
If the form <TT
CLASS="LITERAL"
>\dFd+</TT
> is used, additional information
is shown about each selected dictionary, including the underlying
text search template and the option values.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dFp [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dFp+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available text search parsers.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is specified,
only parsers whose names match the pattern are shown.
If the form <TT
CLASS="LITERAL"
>\dFp+</TT
> is used, a full description of
each parser is shown, including the underlying functions and the
list of recognized token types.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dFt [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dFt+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available text search templates.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is specified,
only templates whose names match the pattern are shown.
If the form <TT
CLASS="LITERAL"
>\dFt+</TT
> is used, additional information
is shown about each template, including the underlying function names.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dg [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all database roles. If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is specified, only
those roles whose names match the pattern are listed.
(This command is now effectively the same as <TT
CLASS="LITERAL"
>\du</TT
>.)
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\distvS [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> This is not the actual command name: the letters
<TT
CLASS="LITERAL"
>i</TT
>, <TT
CLASS="LITERAL"
>s</TT
>,
<TT
CLASS="LITERAL"
>t</TT
>, <TT
CLASS="LITERAL"
>v</TT
>,
<TT
CLASS="LITERAL"
>S</TT
> 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 <TT
CLASS="LITERAL"
>S</TT
> restricts
the listing to system objects; without <TT
CLASS="LITERAL"
>S</TT
>,
only non-system objects are shown. If <TT
CLASS="LITERAL"
>+</TT
> is
appended to the command name, each object is listed with its
associated description, if any.
</P
><P
> If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is
specified, only objects whose names match the pattern are listed.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dl</TT
></DT
><DD
><P
> This is an alias for <TT
CLASS="COMMAND"
>\lo_list</TT
>, which shows a
list of large objects.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dn [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dn+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all available schemas (namespaces). If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> (a regular expression)
is specified, only schemas whose names match the pattern are listed.
Non-local temporary schemas are suppressed. If <TT
CLASS="LITERAL"
>+</TT
>
is appended to the command name, each object is listed with its associated
permissions and description, if any.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\do [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists available operators with their operand and return types.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is
specified, only operators whose names match the pattern are listed.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dp [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Produces a list of all available tables, views and sequences with their
associated access privileges.
If <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is
specified, only tables, views and sequences whose names match the pattern are listed.
</P
><P
> The <A
HREF="sql-grant.html"
><I
>GRANT</I
></A
> and
<A
HREF="sql-revoke.html"
><I
>REVOKE</I
></A
>
commands are used to set access privileges.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\dT [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
><BR><TT
CLASS="LITERAL"
>\dT+ [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all data types or only those that match <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>. The command form
<TT
CLASS="LITERAL"
>\dT+</TT
> shows extra information.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\du [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Lists all database roles, or only those that match <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\edit</TT
> (or <TT
CLASS="LITERAL"
>\e</TT
>) <TT
CLASS="LITERAL"
>[ <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> ]</TT
></DT
><DD
><P
> If <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> 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.
</P
><P
> The new query buffer is then re-parsed according to the normal
rules of <SPAN
CLASS="APPLICATION"
>psql</SPAN
>, where the whole buffer
is treated as a single line. (Thus you cannot make scripts this
way. Use <TT
CLASS="COMMAND"
>\i</TT
> 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.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> searches the environment
variables <TT
CLASS="ENVAR"
>PSQL_EDITOR</TT
>, <TT
CLASS="ENVAR"
>EDITOR</TT
>, and
<TT
CLASS="ENVAR"
>VISUAL</TT
> (in that order) for an editor to use. If
all of them are unset, <TT
CLASS="FILENAME"
>vi</TT
> is used on Unix
systems, <TT
CLASS="FILENAME"
>notepad.exe</TT
> on Windows systems.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\echo <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
> [ ... ]</TT
></DT
><DD
><P
> 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:
</P><PRE
CLASS="PROGRAMLISTING"
>=> <KBD
CLASS="USERINPUT"
>\echo `date`</KBD
>
Tue Oct 26 21:40:57 CEST 1999</PRE
><P>
If the first argument is an unquoted <TT
CLASS="LITERAL"
>-n</TT
> the trailing
newline is not written.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> If you use the <TT
CLASS="COMMAND"
>\o</TT
> command to redirect your
query output you might wish to use <TT
CLASS="COMMAND"
>\qecho</TT
>
instead of this command.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\encoding [ <TT
CLASS="REPLACEABLE"
><I
>encoding</I
></TT
> ]</TT
></DT
><DD
><P
> Sets the client character set encoding. Without an argument, this command
shows the current encoding.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\f [ <TT
CLASS="REPLACEABLE"
><I
>string</I
></TT
> ]</TT
></DT
><DD
><P
> Sets the field separator for unaligned query output. The default
is the vertical bar (<TT
CLASS="LITERAL"
>|</TT
>). See also
<TT
CLASS="COMMAND"
>\pset</TT
> for a generic way of setting output
options.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\g</TT
> [ { <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> | <TT
CLASS="LITERAL"
>|</TT
><TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
> } ]</DT
><DD
><P
> Sends the current query input buffer to the server and
optionally stores the query's output in <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> or pipes the output
into a separate Unix shell executing <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>. A bare
<TT
CLASS="LITERAL"
>\g</TT
> is virtually equivalent to a semicolon. A
<TT
CLASS="LITERAL"
>\g</TT
> with argument is a <SPAN
CLASS="QUOTE"
>"one-shot"</SPAN
>
alternative to the <TT
CLASS="COMMAND"
>\o</TT
> command.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\help</TT
> (or <TT
CLASS="LITERAL"
>\h</TT
>) <TT
CLASS="LITERAL"
>[ <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
> ]</TT
></DT
><DD
><P
> Gives syntax help on the specified <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
command. If <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>
is not specified, then <SPAN
CLASS="APPLICATION"
>psql</SPAN
> will list
all the commands for which syntax help is available. If
<TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
> is an
asterisk (<TT
CLASS="LITERAL"
>*</TT
>), then syntax help on all
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> commands is shown.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> To simplify typing, commands that consists of several words do
not have to be quoted. Thus it is fine to type <KBD
CLASS="USERINPUT"
>\help
alter table</KBD
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\H</TT
></DT
><DD
><P
> Turns on <ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> query output format. If the
<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> format is already on, it is switched
back to the default aligned text format. This command is for
compatibility and convenience, but see <TT
CLASS="COMMAND"
>\pset</TT
>
about setting other output options.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\i <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
></DT
><DD
><P
> Reads input from the file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> and executes it as
though it had been typed on the keyboard.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> If you want to see the lines on the screen as they are read you
must set the variable <TT
CLASS="VARNAME"
>ECHO</TT
> to
<TT
CLASS="LITERAL"
>all</TT
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\l</TT
> (or <TT
CLASS="LITERAL"
>\list</TT
>)<BR><TT
CLASS="LITERAL"
>\l+</TT
> (or <TT
CLASS="LITERAL"
>\list+</TT
>)</DT
><DD
><P
> List the names, owners, and character set encodings of all the databases in
the server. If <TT
CLASS="LITERAL"
>+</TT
> is appended to the command
name, database descriptions are also displayed.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\lo_export <TT
CLASS="REPLACEABLE"
><I
>loid</I
></TT
> <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></TT
></DT
><DD
><P
> Reads the large object with <ACRONYM
CLASS="ACRONYM"
>OID</ACRONYM
> <TT
CLASS="REPLACEABLE"
><I
>loid</I
></TT
> from the database and
writes it to <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>. Note that this is
subtly different from the server function
<CODE
CLASS="FUNCTION"
>lo_export</CODE
>, which acts with the permissions
of the user that the database server runs as and on the server's
file system.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> Use <TT
CLASS="COMMAND"
>\lo_list</TT
> to find out the large object's
<ACRONYM
CLASS="ACRONYM"
>OID</ACRONYM
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\lo_import <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> [ <TT
CLASS="REPLACEABLE"
><I
>comment</I
></TT
> ]</TT
></DT
><DD
><P
> Stores the file into a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
large object. Optionally, it associates the given
comment with the object. Example:
</P><PRE
CLASS="PROGRAMLISTING"
>foo=> <KBD
CLASS="USERINPUT"
>\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'</KBD
>
lo_import 152801</PRE
><P>
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
<TT
CLASS="COMMAND"
>\lo_list</TT
> command.
</P
><P
> Note that this command is subtly different from the server-side
<CODE
CLASS="FUNCTION"
>lo_import</CODE
> because it acts as the local user
on the local file system, rather than the server's user and file
system.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\lo_list</TT
></DT
><DD
><P
> Shows a list of all <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
large objects currently stored in the database,
along with any comments provided for them.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\lo_unlink <TT
CLASS="REPLACEABLE"
><I
>loid</I
></TT
></TT
></DT
><DD
><P
> Deletes the large object with <ACRONYM
CLASS="ACRONYM"
>OID</ACRONYM
>
<TT
CLASS="REPLACEABLE"
><I
>loid</I
></TT
> from the
database.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> Use <TT
CLASS="COMMAND"
>\lo_list</TT
> to find out the large object's
<ACRONYM
CLASS="ACRONYM"
>OID</ACRONYM
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\o</TT
> [ {<TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> | <TT
CLASS="LITERAL"
>|</TT
><TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>} ]</DT
><DD
><P
> Saves future query results to the file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> or pipes future results
into a separate Unix shell to execute <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>. If no arguments are
specified, the query output will be reset to the standard output.
</P
><P
> <SPAN
CLASS="QUOTE"
>"Query results"</SPAN
> 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 <TT
CLASS="COMMAND"
>\d</TT
>), but not error
messages.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> To intersperse text output in between query results, use
<TT
CLASS="COMMAND"
>\qecho</TT
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\p</TT
></DT
><DD
><P
> Print the current query buffer to the standard output.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\password [ <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
> ]</TT
></DT
><DD
><P
> 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 <TT
CLASS="COMMAND"
>ALTER ROLE</TT
> command. This
makes sure that the new password does not appear in cleartext in the
command history, the server log, or elsewhere.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\prompt [ <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
> ] <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
></TT
></DT
><DD
><P
> Prompts the user to set variable <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
>. An optional prompt, <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
>, can be specified. (For multi-word
prompts, use single-quotes.)
</P
><P
> By default, <TT
CLASS="LITERAL"
>\prompt</TT
> uses the terminal for input and
output. However, if the <TT
CLASS="OPTION"
>-f</TT
> command line switch is
used, <TT
CLASS="LITERAL"
>\prompt</TT
> uses standard input and standard output.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\pset <TT
CLASS="REPLACEABLE"
><I
>parameter</I
></TT
> [ <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> ]</TT
></DT
><DD
><P
> This command sets options affecting the output of query result
tables. <TT
CLASS="REPLACEABLE"
><I
>parameter</I
></TT
>
describes which option is to be set. The semantics of
<TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> depend
thereon.
</P
><P
> Adjustable printing options are:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>format</TT
></DT
><DD
><P
> Sets the output format to one of <TT
CLASS="LITERAL"
>unaligned</TT
>,
<TT
CLASS="LITERAL"
>aligned</TT
>, <TT
CLASS="LITERAL"
>html</TT
>,
<TT
CLASS="LITERAL"
>latex</TT
>, or <TT
CLASS="LITERAL"
>troff-ms</TT
>.
Unique abbreviations are allowed. (That would mean one letter
is enough.)
</P
><P
> <SPAN
CLASS="QUOTE"
>"Unaligned"</SPAN
> 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).
<SPAN
CLASS="QUOTE"
>"Aligned"</SPAN
> mode is the standard, human-readable,
nicely formatted text output that is default. The
<SPAN
CLASS="QUOTE"
>"<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
>"</SPAN
> and
<SPAN
CLASS="QUOTE"
>"LaTeX"</SPAN
> 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 <ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
>, but in LaTeX you must
have a complete document wrapper.)
</P
></DD
><DT
><TT
CLASS="LITERAL"
>border</TT
></DT
><DD
><P
> 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
<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> mode, this will translate directly
into the <TT
CLASS="LITERAL"
>border=...</TT
> attribute, in the
others only values 0 (no border), 1 (internal dividing lines),
and 2 (table frame) make sense.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>expanded</TT
> (or <TT
CLASS="LITERAL"
>x</TT
>)</DT
><DD
><P
> You can specify an optional second argument, if it is provided it
may be either <TT
CLASS="LITERAL"
>on</TT
> or <TT
CLASS="LITERAL"
>off</TT
>
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 <SPAN
CLASS="QUOTE"
>"horizontal"</SPAN
> mode.
</P
><P
> Expanded mode is supported by all four output formats.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>null</TT
></DT
><DD
><P
> 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 <TT
CLASS="LITERAL"
>\pset null
'(null)'</TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>fieldsep</TT
></DT
><DD
><P
> 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 <TT
CLASS="LITERAL"
>\pset fieldsep
'\t'</TT
>. The default field separator is
<TT
CLASS="LITERAL"
>'|'</TT
> (a vertical bar).
</P
></DD
><DT
><TT
CLASS="LITERAL"
>footer</TT
></DT
><DD
><P
> You can specify an optional second argument, if it is provided it
may be either <TT
CLASS="LITERAL"
>on</TT
> or <TT
CLASS="LITERAL"
>off</TT
>
which will enable or disable display of the default footer
<TT
CLASS="LITERAL"
>(x rows)</TT
>. If the second argument is not
provided then we will toggle between on and off.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>numericlocale</TT
></DT
><DD
><P
> You can specify an optional second argument, if it is provided it
may be either <TT
CLASS="LITERAL"
>on</TT
> or <TT
CLASS="LITERAL"
>off</TT
>
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.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>recordsep</TT
></DT
><DD
><P
> Specifies the record (line) separator to use in unaligned
output mode. The default is a newline character.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>tuples_only</TT
> (or <TT
CLASS="LITERAL"
>t</TT
>)</DT
><DD
><P
> You can specify an optional second argument, if it is provided it
may be either <TT
CLASS="LITERAL"
>on</TT
> or <TT
CLASS="LITERAL"
>off</TT
>
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.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>title [ <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
> ]</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>tableattr</TT
> (or <TT
CLASS="LITERAL"
>T</TT
>) <TT
CLASS="LITERAL"
>[ <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
> ]</TT
></DT
><DD
><P
> Allows you to specify any attributes to be placed inside the
<ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> <CODE
CLASS="SGMLTAG"
>table</CODE
> tag. This
could for example be <TT
CLASS="LITERAL"
>cellpadding</TT
> or
<TT
CLASS="LITERAL"
>bgcolor</TT
>. Note that you probably don't want
to specify <TT
CLASS="LITERAL"
>border</TT
> here, as that is already
taken care of by <TT
CLASS="LITERAL"
>\pset border</TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>pager</TT
></DT
><DD
><P
> Controls use of a pager for query and <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
help output. If the environment variable <TT
CLASS="ENVAR"
>PAGER</TT
>
is set, the output is piped to the specified program.
Otherwise a platform-dependent default (such as
<TT
CLASS="FILENAME"
>more</TT
>) is used.
</P
><P
> 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 terminal and will not fit on the screen.
(<SPAN
CLASS="APPLICATION"
>psql</SPAN
> does not do a perfect job of estimating
when to use the pager.) <TT
CLASS="LITERAL"
>\pset pager</TT
> turns the
pager on and off. Pager can also be set to <TT
CLASS="LITERAL"
>always</TT
>,
which causes the pager to be always used, or you can set the pager
to <TT
CLASS="LITERAL"
>on</TT
> which will enable the usage of the pager when
appropriate, or you can set the pager to <TT
CLASS="LITERAL"
>off</TT
> which
will disable the pager.
</P
></DD
></DL
></DIV
><P>
</P
><P
> Illustrations on how these different formats look can be seen in
the <A
HREF="app-psql.html#APP-PSQL-EXAMPLES"
><I
>Examples</I
></A
> section.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> There are various shortcut commands for <TT
CLASS="COMMAND"
>\pset</TT
>. See
<TT
CLASS="COMMAND"
>\a</TT
>, <TT
CLASS="COMMAND"
>\C</TT
>, <TT
CLASS="COMMAND"
>\H</TT
>,
<TT
CLASS="COMMAND"
>\t</TT
>, <TT
CLASS="COMMAND"
>\T</TT
>, and <TT
CLASS="COMMAND"
>\x</TT
>.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> It is an error to call <TT
CLASS="COMMAND"
>\pset</TT
> without
arguments. In the future this call might show the current status
of all printing options.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\q</TT
></DT
><DD
><P
> Quits the <SPAN
CLASS="APPLICATION"
>psql</SPAN
> program.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\qecho <TT
CLASS="REPLACEABLE"
><I
>text</I
></TT
> [ ... ] </TT
></DT
><DD
><P
> This command is identical to <TT
CLASS="COMMAND"
>\echo</TT
> except
that the output will be written to the query output channel, as
set by <TT
CLASS="COMMAND"
>\o</TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\r</TT
></DT
><DD
><P
> Resets (clears) the query buffer.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\s [ <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> ]</TT
></DT
><DD
><P
> Print or save the command line history to <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>. If <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> is omitted, the history
is written to the standard output. This option is only available
if <SPAN
CLASS="APPLICATION"
>psql</SPAN
> is configured to use the
<ACRONYM
CLASS="ACRONYM"
>GNU</ACRONYM
> <SPAN
CLASS="APPLICATION"
>Readline</SPAN
> library.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\set [ <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
> [ <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> [ ... ] ] ]</TT
></DT
><DD
><P
> Sets the internal variable <TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
> to <TT
CLASS="REPLACEABLE"
><I
>value</I
></TT
> 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 <TT
CLASS="COMMAND"
>\unset</TT
> command.
</P
><P
> Valid variable names can contain characters, digits, and
underscores. See the section <A
HREF="app-psql.html#APP-PSQL-VARIABLES"
><I
>Variables</I
></A
> below for details.
Variable names are case-sensitive.
</P
><P
> Although you are welcome to set any variable to anything you
want, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> treats several variables
as special. They are documented in the section about variables.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This command is totally separate from the <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
command <A
HREF="sql-set.html"
><I
>SET</I
></A
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="LITERAL"
>\t</TT
></DT
><DD
><P
> Toggles the display of output column name headings and row count
footer. This command is equivalent to <TT
CLASS="LITERAL"
>\pset
tuples_only</TT
> and is provided for convenience.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\T <TT
CLASS="REPLACEABLE"
><I
>table_options</I
></TT
></TT
></DT
><DD
><P
> Allows you to specify attributes to be placed within the
<CODE
CLASS="SGMLTAG"
>table</CODE
> tag in <ACRONYM
CLASS="ACRONYM"
>HTML</ACRONYM
> tabular
output mode. This command is equivalent to <TT
CLASS="LITERAL"
>\pset
tableattr <TT
CLASS="REPLACEABLE"
><I
>table_options</I
></TT
></TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\timing</TT
></DT
><DD
><P
> Toggles a display of how long each SQL statement takes, in milliseconds.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\w</TT
> {<TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> | <TT
CLASS="REPLACEABLE"
><I
>|command</I
></TT
>}</DT
><DD
><P
> Outputs the current query buffer to the file <TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
> or pipes it to the Unix
command <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\x</TT
></DT
><DD
><P
> Toggles expanded table formatting mode. As such it is equivalent to
<TT
CLASS="LITERAL"
>\pset expanded</TT
>.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\z [ <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> ]</TT
></DT
><DD
><P
> Produces a list of all available tables, views and sequences with their
associated access privileges.
If a <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> is
specified, only tables,views and sequences whose names match the pattern are listed.
</P
><P
> The <A
HREF="sql-grant.html"
><I
>GRANT</I
></A
> and
<A
HREF="sql-revoke.html"
><I
>REVOKE</I
></A
>
commands are used to set access privileges.
</P
><P
> This is an alias for <TT
CLASS="COMMAND"
>\dp</TT
> (<SPAN
CLASS="QUOTE"
>"display
privileges"</SPAN
>).
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\! [ <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
> ]</TT
></DT
><DD
><P
> Escapes to a separate Unix shell or executes the Unix command
<TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>. The
arguments are not further interpreted, the shell will see them
as is.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>\?</TT
></DT
><DD
><P
> Shows help information about the backslash commands.
</P
></DD
></DL
></DIV
><P>
</P
><DIV
CLASS="REFSECT3"
><A
NAME="APP-PSQL-PATTERNS"
></A
><H4
>Patterns</H4
><A
NAME="AEN65307"
></A
><P
> The various <TT
CLASS="LITERAL"
>\d</TT
> commands accept a <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> 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, <TT
CLASS="LITERAL"
>\dt FOO</TT
> will display the table named
<TT
CLASS="LITERAL"
>foo</TT
>. 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,
<TT
CLASS="LITERAL"
>\dt "FOO""BAR"</TT
> will display the table named
<TT
CLASS="LITERAL"
>FOO"BAR</TT
> (not <TT
CLASS="LITERAL"
>foo"bar</TT
>). Unlike the normal
rules for SQL names, you can put double quotes around just part
of a pattern, for instance <TT
CLASS="LITERAL"
>\dt FOO"FOO"BAR</TT
> will display
the table named <TT
CLASS="LITERAL"
>fooFOObar</TT
>.
</P
><P
> Within a pattern, <TT
CLASS="LITERAL"
>*</TT
> matches any sequence of characters
(including no characters) and <TT
CLASS="LITERAL"
>?</TT
> matches any single character.
(This notation is comparable to Unix shell file name patterns.)
For example, <TT
CLASS="LITERAL"
>\dt int*</TT
> displays all tables whose names
begin with <TT
CLASS="LITERAL"
>int</TT
>. But within double quotes, <TT
CLASS="LITERAL"
>*</TT
>
and <TT
CLASS="LITERAL"
>?</TT
> lose these special meanings and are just matched
literally.
</P
><P
> A pattern that contains a dot (<TT
CLASS="LITERAL"
>.</TT
>) is interpreted as a schema
name pattern followed by an object name pattern. For example,
<TT
CLASS="LITERAL"
>\dt foo*.*bar*</TT
> displays all tables whose table name
includes <TT
CLASS="LITERAL"
>bar</TT
> that are in schemas whose schema name
starts with <TT
CLASS="LITERAL"
>foo</TT
>. 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.
</P
><P
> Advanced users can use regular-expression notations such as character
classes, for example <TT
CLASS="LITERAL"
>[0-9]</TT
> to match any digit. All regular
expression special characters work as specified in
<A
HREF="functions-matching.html#FUNCTIONS-POSIX-REGEXP"
>Section 9.7.3</A
>, except for <TT
CLASS="LITERAL"
>.</TT
> which
is taken as a separator as mentioned above, <TT
CLASS="LITERAL"
>*</TT
> which is
translated to the regular-expression notation <TT
CLASS="LITERAL"
>.*</TT
>,
<TT
CLASS="LITERAL"
>?</TT
> which is translated to <TT
CLASS="LITERAL"
>.</TT
>, and
<TT
CLASS="LITERAL"
>$</TT
> which is matched literally. You can emulate
these pattern characters at need by writing
<TT
CLASS="LITERAL"
>?</TT
> for <TT
CLASS="LITERAL"
>.</TT
>,
<TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>R</I
></TT
>+|)</TT
> for
<TT
CLASS="LITERAL"
><TT
CLASS="REPLACEABLE"
><I
>R</I
></TT
>*</TT
>, or
<TT
CLASS="LITERAL"
>(<TT
CLASS="REPLACEABLE"
><I
>R</I
></TT
>|)</TT
> for
<TT
CLASS="LITERAL"
><TT
CLASS="REPLACEABLE"
><I
>R</I
></TT
>?</TT
>.
<TT
CLASS="LITERAL"
>$</TT
> 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, <TT
CLASS="LITERAL"
>$</TT
>
is automatically appended to your pattern). Write <TT
CLASS="LITERAL"
>*</TT
> 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 <TT
CLASS="LITERAL"
>\do</TT
>).
</P
><P
> Whenever the <TT
CLASS="REPLACEABLE"
><I
>pattern</I
></TT
> parameter
is omitted completely, the <TT
CLASS="LITERAL"
>\d</TT
> commands display all objects
that are visible in the current schema search path — this is
equivalent to using the pattern <TT
CLASS="LITERAL"
>*</TT
>.
To see all objects in the database, use the pattern <TT
CLASS="LITERAL"
>*.*</TT
>.
</P
></DIV
></DIV
><DIV
CLASS="REFSECT2"
><A
NAME="AEN65360"
></A
><H3
>Advanced features</H3
><DIV
CLASS="REFSECT3"
><A
NAME="APP-PSQL-VARIABLES"
></A
><H4
>Variables</H4
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> meta-command
<TT
CLASS="COMMAND"
>\set</TT
>:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set foo bar</KBD
></PRE
><P>
sets the variable <TT
CLASS="LITERAL"
>foo</TT
> to the value
<TT
CLASS="LITERAL"
>bar</TT
>. To retrieve the content of the variable, precede
the name with a colon and use it as the argument of any slash
command:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\echo :foo</KBD
>
bar</PRE
><P>
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The arguments of <TT
CLASS="COMMAND"
>\set</TT
> are subject to the same
substitution rules as with other commands. Thus you can construct
interesting references such as <TT
CLASS="LITERAL"
>\set :foo
'something'</TT
> and get <SPAN
CLASS="QUOTE"
>"soft links"</SPAN
> or
<SPAN
CLASS="QUOTE"
>"variable variables"</SPAN
> of <SPAN
CLASS="PRODUCTNAME"
>Perl</SPAN
>
or <SPAN
CLASS="PRODUCTNAME"
><ACRONYM
CLASS="ACRONYM"
>PHP</ACRONYM
></SPAN
> fame,
respectively. Unfortunately (or fortunately?), there is no way to do
anything useful with these constructs. On the other hand,
<TT
CLASS="LITERAL"
>\set bar :foo</TT
> is a perfectly valid way to copy a
variable.
</P
></BLOCKQUOTE
></DIV
><P
> If you call <TT
CLASS="COMMAND"
>\set</TT
> without a second argument, the
variable is set, with an empty string as value. To unset (or delete) a
variable, use the command <TT
CLASS="COMMAND"
>\unset</TT
>.
</P
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
>'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 <SPAN
CLASS="APPLICATION"
>psql</SPAN
>. 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.
</P
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="VARNAME"
>AUTOCOMMIT</TT
></DT
><DD
><P
> When <TT
CLASS="LITERAL"
>on</TT
> (the default), each SQL command is automatically
committed upon successful completion. To postpone commit in this
mode, you must enter a <TT
CLASS="COMMAND"
>BEGIN</TT
> or <TT
CLASS="COMMAND"
>START
TRANSACTION</TT
> SQL command. When <TT
CLASS="LITERAL"
>off</TT
> or unset, SQL
commands are not committed until you explicitly issue
<TT
CLASS="COMMAND"
>COMMIT</TT
> or <TT
CLASS="COMMAND"
>END</TT
>. The autocommit-off
mode works by issuing an implicit <TT
CLASS="COMMAND"
>BEGIN</TT
> for you, just
before any command that is not already in a transaction block and
is not itself a <TT
CLASS="COMMAND"
>BEGIN</TT
> or other transaction-control
command, nor a command that cannot be executed inside a transaction
block (such as <TT
CLASS="COMMAND"
>VACUUM</TT
>).
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> In autocommit-off mode, you must explicitly abandon any failed
transaction by entering <TT
CLASS="COMMAND"
>ABORT</TT
> or <TT
CLASS="COMMAND"
>ROLLBACK</TT
>.
Also keep in mind that if you exit the session
without committing, your work will be lost.
</P
></BLOCKQUOTE
></DIV
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> The autocommit-on mode is <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>'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
<TT
CLASS="FILENAME"
>psqlrc</TT
> file or your
<TT
CLASS="FILENAME"
>~/.psqlrc</TT
> file.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>DBNAME</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>ECHO</TT
></DT
><DD
><P
> If set to <TT
CLASS="LITERAL"
>all</TT
>, 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 <TT
CLASS="OPTION"
>-a</TT
>. If set to
<TT
CLASS="LITERAL"
>queries</TT
>,
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> merely prints all queries as
they are sent to the server. The switch for this is
<TT
CLASS="OPTION"
>-e</TT
>.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>ECHO_HIDDEN</TT
></DT
><DD
><P
> When this variable is set and a backslash command queries the
database, the query is first shown. This way you can study the
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> internals and provide
similar functionality in your own programs. (To select this behavior
on program start-up, use the switch <TT
CLASS="OPTION"
>-E</TT
>.) If you set
the variable to the value <TT
CLASS="LITERAL"
>noexec</TT
>, the queries are
just shown but are not actually sent to the server and executed.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>ENCODING</TT
></DT
><DD
><P
> The current client character set encoding.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>FETCH_COUNT</TT
></DT
><DD
><P
> If this variable is set to an integer value > 0,
the results of <TT
CLASS="COMMAND"
>SELECT</TT
> 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.
</P
><DIV
CLASS="TIP"
><BLOCKQUOTE
CLASS="TIP"
><P
><B
>Tip: </B
> Although you can use any output format with this feature,
the default <TT
CLASS="LITERAL"
>aligned</TT
> format tends to look bad
because each group of <TT
CLASS="VARNAME"
>FETCH_COUNT</TT
> rows
will be formatted separately, leading to varying column
widths across the row groups. The other output formats work better.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>HISTCONTROL</TT
></DT
><DD
><P
> If this variable is set to <TT
CLASS="LITERAL"
>ignorespace</TT
>,
lines which begin with a space are not entered into the history
list. If set to a value of <TT
CLASS="LITERAL"
>ignoredups</TT
>, lines
matching the previous history line are not entered. A value of
<TT
CLASS="LITERAL"
>ignoreboth</TT
> 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.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This feature was shamelessly plagiarized from
<SPAN
CLASS="APPLICATION"
>Bash</SPAN
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>HISTFILE</TT
></DT
><DD
><P
> The file name that will be used to store the history list. The default
value is <TT
CLASS="FILENAME"
>~/.psql_history</TT
>. For example, putting:
</P><PRE
CLASS="PROGRAMLISTING"
>\set HISTFILE ~/.psql_history- :DBNAME</PRE
><P>
in <TT
CLASS="FILENAME"
>~/.psqlrc</TT
> will cause
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> to maintain a separate history for
each database.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This feature was shamelessly plagiarized from
<SPAN
CLASS="APPLICATION"
>Bash</SPAN
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>HISTSIZE</TT
></DT
><DD
><P
> The number of commands to store in the command history. The
default value is 500.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This feature was shamelessly plagiarized from
<SPAN
CLASS="APPLICATION"
>Bash</SPAN
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>HOST</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>IGNOREEOF</TT
></DT
><DD
><P
> If unset, sending an <ACRONYM
CLASS="ACRONYM"
>EOF</ACRONYM
> character (usually
<B
CLASS="KEYCAP"
>Control</B
>+<B
CLASS="KEYCAP"
>D</B
>)
to an interactive session of <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
will terminate the application. If set to a numeric value,
that many <ACRONYM
CLASS="ACRONYM"
>EOF</ACRONYM
> characters are ignored before the
application terminates. If the variable is set but has no
numeric value, the default is 10.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This feature was shamelessly plagiarized from
<SPAN
CLASS="APPLICATION"
>Bash</SPAN
>.
</P
></BLOCKQUOTE
></DIV
></DD
><DT
><TT
CLASS="VARNAME"
>LASTOID</TT
></DT
><DD
><P
> The value of the last affected OID, as returned from an
<TT
CLASS="COMMAND"
>INSERT</TT
> or <TT
CLASS="COMMAND"
>lo_insert</TT
>
command. This variable is only guaranteed to be valid until
after the result of the next <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> command has
been displayed.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>ON_ERROR_ROLLBACK</TT
></DT
><DD
><P
> When <TT
CLASS="LITERAL"
>on</TT
>, if a statement in a transaction block
generates an error, the error is ignored and the transaction
continues. When <TT
CLASS="LITERAL"
>interactive</TT
>, such errors are only
ignored in interactive sessions, and not when reading script
files. When <TT
CLASS="LITERAL"
>off</TT
> (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 <TT
CLASS="COMMAND"
>SAVEPOINT</TT
> for you, just before each command
that is in a transaction block, and rolls back to the savepoint
on error.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>ON_ERROR_STOP</TT
></DT
><DD
><P
> By default, if non-interactive scripts encounter an error, such
as a malformed <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> command or internal
meta-command, processing continues. This has been the
traditional behavior of <SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> session but rather using the
<TT
CLASS="OPTION"
>-f</TT
> option, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> will
return error code 3, to distinguish this case from fatal error
conditions (error code 1).
</P
></DD
><DT
><TT
CLASS="VARNAME"
>PORT</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>PROMPT1</TT
><BR><TT
CLASS="VARNAME"
>PROMPT2</TT
><BR><TT
CLASS="VARNAME"
>PROMPT3</TT
></DT
><DD
><P
> These specify what the prompts <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
issues should look like. See <A
HREF="app-psql.html#APP-PSQL-PROMPTING"
><I
>Prompting</I
></A
> below.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>QUIET</TT
></DT
><DD
><P
> This variable is equivalent to the command line option
<TT
CLASS="OPTION"
>-q</TT
>. It is probably not too useful in
interactive mode.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>SINGLELINE</TT
></DT
><DD
><P
> This variable is equivalent to the command line option
<TT
CLASS="OPTION"
>-S</TT
>.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>SINGLESTEP</TT
></DT
><DD
><P
> This variable is equivalent to the command line option
<TT
CLASS="OPTION"
>-s</TT
>.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>USER</TT
></DT
><DD
><P
> 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.
</P
></DD
><DT
><TT
CLASS="VARNAME"
>VERBOSITY</TT
></DT
><DD
><P
> This variable can be set to the values <TT
CLASS="LITERAL"
>default</TT
>,
<TT
CLASS="LITERAL"
>verbose</TT
>, or <TT
CLASS="LITERAL"
>terse</TT
> to control the verbosity
of error reports.
</P
></DD
></DL
></DIV
></DIV
><DIV
CLASS="REFSECT3"
><A
NAME="AEN65582"
></A
><H4
><ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> Interpolation</H4
><P
> An additional useful feature of <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
variables is that you can substitute (<SPAN
CLASS="QUOTE"
>"interpolate"</SPAN
>)
them into regular <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> statements. The syntax for
this is again to prepend the variable name with a colon
(<TT
CLASS="LITERAL"
>:</TT
>):
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set foo 'my_table'</KBD
>
testdb=> <KBD
CLASS="USERINPUT"
>SELECT * FROM :foo;</KBD
></PRE
><P>
would then query the table <TT
CLASS="LITERAL"
>my_table</TT
>. 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 <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> entities.
</P
><P
> A popular application of this facility is to refer to the last
inserted <ACRONYM
CLASS="ACRONYM"
>OID</ACRONYM
> 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:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set content '''' `cat my_file.txt` ''''</KBD
>
testdb=> <KBD
CLASS="USERINPUT"
>INSERT INTO my_table VALUES (:content);</KBD
></PRE
><P>
One problem with this approach is that <TT
CLASS="FILENAME"
>my_file.txt</TT
>
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 <TT
CLASS="COMMAND"
>sed</TT
>:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set content '''' `sed -e "s/'/''/g" < my_file.txt` ''''</KBD
></PRE
><P>
If you are using non-standard-conforming strings then you'll also need
to double backslashes. This is a bit tricky:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set content '''' `sed -e "s/'/''/g" -e 's/\\/\\\\/g' < my_file.txt` ''''</KBD
></PRE
><P>
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 <TT
CLASS="COMMAND"
>sed</TT
>, however, so
we need to double them. (Perhaps
at one point you thought it was great that all Unix commands use the
same escape character.)
</P
><P
> Since colons can legally appear in SQL commands, the following rule
applies: the character sequence
<SPAN
CLASS="QUOTE"
>":name"</SPAN
> is not changed unless <SPAN
CLASS="QUOTE"
>"name"</SPAN
> 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 <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> for
embedded query languages, such as <SPAN
CLASS="APPLICATION"
>ECPG</SPAN
>.
The colon syntax for array slices and type casts are
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> extensions, hence the
conflict.)
</P
></DIV
><DIV
CLASS="REFSECT3"
><A
NAME="APP-PSQL-PROMPTING"
></A
><H4
>Prompting</H4
><P
> The prompts <SPAN
CLASS="APPLICATION"
>psql</SPAN
> issues can be customized
to your preference. The three variables <TT
CLASS="VARNAME"
>PROMPT1</TT
>,
<TT
CLASS="VARNAME"
>PROMPT2</TT
>, and <TT
CLASS="VARNAME"
>PROMPT3</TT
> contain strings
and special escape sequences that describe the appearance of the
prompt. Prompt 1 is the normal prompt that is issued when
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> 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 <ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
>
<TT
CLASS="COMMAND"
>COPY</TT
> command and you are expected to type in the
row values on the terminal.
</P
><P
> The value of the selected prompt variable is printed literally,
except where a percent sign (<TT
CLASS="LITERAL"
>%</TT
>) is encountered.
Depending on the next character, certain other text is substituted
instead. Defined substitutions are:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="LITERAL"
>%M</TT
></DT
><DD
><P
> The full host name (with domain name) of the database server,
or <TT
CLASS="LITERAL"
>[local]</TT
> if the connection is over a Unix
domain socket, or
<TT
CLASS="LITERAL"
>[local:<TT
CLASS="REPLACEABLE"
><I
>/dir/name</I
></TT
>]</TT
>,
if the Unix domain socket is not at the compiled in default
location.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%m</TT
></DT
><DD
><P
> The host name of the database server, truncated at the
first dot, or <TT
CLASS="LITERAL"
>[local]</TT
> if the connection is
over a Unix domain socket.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%></TT
></DT
><DD
><P
>The port number at which the database server is listening.</P
></DD
><DT
><TT
CLASS="LITERAL"
>%n</TT
></DT
><DD
><P
> The database session user name. (The expansion of this
value might change during a database session as the result
of the command <TT
CLASS="COMMAND"
>SET SESSION
AUTHORIZATION</TT
>.)
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%/</TT
></DT
><DD
><P
>The name of the current database.</P
></DD
><DT
><TT
CLASS="LITERAL"
>%~</TT
></DT
><DD
><P
>Like <TT
CLASS="LITERAL"
>%/</TT
>, but the output is <TT
CLASS="LITERAL"
>~</TT
>
(tilde) if the database is your default database.</P
></DD
><DT
><TT
CLASS="LITERAL"
>%#</TT
></DT
><DD
><P
> If the session user is a database superuser, then a
<TT
CLASS="LITERAL"
>#</TT
>, otherwise a <TT
CLASS="LITERAL"
>></TT
>.
(The expansion of this value might change during a database
session as the result of the command <TT
CLASS="COMMAND"
>SET SESSION
AUTHORIZATION</TT
>.)
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%R</TT
></DT
><DD
><P
> In prompt 1 normally <TT
CLASS="LITERAL"
>=</TT
>, but <TT
CLASS="LITERAL"
>^</TT
> if
in single-line mode, and <TT
CLASS="LITERAL"
>!</TT
> if the session is
disconnected from the database (which can happen if
<TT
CLASS="COMMAND"
>\connect</TT
> fails). In prompt 2 the sequence is
replaced by <TT
CLASS="LITERAL"
>-</TT
>, <TT
CLASS="LITERAL"
>*</TT
>, a single quote,
a double quote, or a dollar sign, depending on whether
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> expects more input because the
command wasn't terminated yet, because you are inside a
<TT
CLASS="LITERAL"
>/* ... */</TT
> comment, or because you are inside
a quoted or dollar-escaped string. In prompt 3 the sequence doesn't
produce anything.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%x</TT
></DT
><DD
><P
> Transaction status: an empty string when not in a transaction
block, or <TT
CLASS="LITERAL"
>*</TT
> when in a transaction block, or
<TT
CLASS="LITERAL"
>!</TT
> when in a failed transaction block, or <TT
CLASS="LITERAL"
>?</TT
>
when the transaction state is indeterminate (for example, because
there is no connection).
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%</TT
><TT
CLASS="REPLACEABLE"
><I
>digits</I
></TT
></DT
><DD
><P
> The character with the indicated octal code is substituted.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%:</TT
><TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
><TT
CLASS="LITERAL"
>:</TT
></DT
><DD
><P
> The value of the <SPAN
CLASS="APPLICATION"
>psql</SPAN
> variable
<TT
CLASS="REPLACEABLE"
><I
>name</I
></TT
>. See the
section <A
HREF="app-psql.html#APP-PSQL-VARIABLES"
><I
>Variables</I
></A
> for details.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%`</TT
><TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
><TT
CLASS="LITERAL"
>`</TT
></DT
><DD
><P
> The output of <TT
CLASS="REPLACEABLE"
><I
>command</I
></TT
>, similar to ordinary
<SPAN
CLASS="QUOTE"
>"back-tick"</SPAN
> substitution.
</P
></DD
><DT
><TT
CLASS="LITERAL"
>%[</TT
> ... <TT
CLASS="LITERAL"
>%]</TT
></DT
><DD
><P
> 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 <SPAN
CLASS="APPLICATION"
>Readline</SPAN
> to work properly, these
non-printing control characters must be designated as invisible
by surrounding them with <TT
CLASS="LITERAL"
>%[</TT
> and
<TT
CLASS="LITERAL"
>%]</TT
>. Multiple pairs of these can occur within
the prompt. For example:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '</PRE
><P>
results in a boldfaced (<TT
CLASS="LITERAL"
>1;</TT
>) yellow-on-black
(<TT
CLASS="LITERAL"
>33;40</TT
>) prompt on VT100-compatible, color-capable
terminals.
</P
></DD
></DL
></DIV
><P>
To insert a percent sign into your prompt, write
<TT
CLASS="LITERAL"
>%%</TT
>. The default prompts are
<TT
CLASS="LITERAL"
>'%/%R%# '</TT
> for prompts 1 and 2, and
<TT
CLASS="LITERAL"
>'>> '</TT
> for prompt 3.
</P
><DIV
CLASS="NOTE"
><BLOCKQUOTE
CLASS="NOTE"
><P
><B
>Note: </B
> This feature was shamelessly plagiarized from
<SPAN
CLASS="APPLICATION"
>tcsh</SPAN
>.
</P
></BLOCKQUOTE
></DIV
></DIV
><DIV
CLASS="REFSECT3"
><A
NAME="AEN65735"
></A
><H4
>Command-Line Editing</H4
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> supports the <SPAN
CLASS="APPLICATION"
>Readline</SPAN
>
library for convenient line editing and retrieval. The command
history is automatically saved when <SPAN
CLASS="APPLICATION"
>psql</SPAN
>
exits and is reloaded when
<SPAN
CLASS="APPLICATION"
>psql</SPAN
> starts up. Tab-completion is also
supported, although the completion logic makes no claim to be an
<ACRONYM
CLASS="ACRONYM"
>SQL</ACRONYM
> parser. If for some reason you do not like the tab completion, you
can turn it off by putting this in a file named
<TT
CLASS="FILENAME"
>.inputrc</TT
> in your home directory:
</P><PRE
CLASS="PROGRAMLISTING"
>$if psql
set disable-completion on
$endif</PRE
><P>
(This is not a <SPAN
CLASS="APPLICATION"
>psql</SPAN
> but a
<SPAN
CLASS="APPLICATION"
>Readline</SPAN
> feature. Read its documentation
for further details.)
</P
></DIV
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN65747"
></A
><H2
>Environment</H2
><P
></P
><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="ENVAR"
>PAGER</TT
></DT
><DD
><P
> If the query results do not fit on the screen, they are piped
through this command. Typical values are
<TT
CLASS="LITERAL"
>more</TT
> or <TT
CLASS="LITERAL"
>less</TT
>. The default
is platform-dependent. The use of the pager can be disabled by
using the <TT
CLASS="COMMAND"
>\pset</TT
> command.
</P
></DD
><DT
><TT
CLASS="ENVAR"
>PGDATABASE</TT
></DT
><DD
><P
> Default connection database
</P
></DD
><DT
><TT
CLASS="ENVAR"
>PGHOST</TT
><BR><TT
CLASS="ENVAR"
>PGPORT</TT
><BR><TT
CLASS="ENVAR"
>PGUSER</TT
></DT
><DD
><P
> Default connection parameters
</P
></DD
><DT
><TT
CLASS="ENVAR"
>PSQL_EDITOR</TT
><BR><TT
CLASS="ENVAR"
>EDITOR</TT
><BR><TT
CLASS="ENVAR"
>VISUAL</TT
></DT
><DD
><P
> Editor used by the <TT
CLASS="COMMAND"
>\e</TT
> command. The variables
are examined in the order listed; the first that is set is used.
</P
></DD
><DT
><TT
CLASS="ENVAR"
>SHELL</TT
></DT
><DD
><P
> Command executed by the <TT
CLASS="COMMAND"
>\!</TT
> command.
</P
></DD
><DT
><TT
CLASS="ENVAR"
>TMPDIR</TT
></DT
><DD
><P
> Directory for storing temporary files. The default is
<TT
CLASS="FILENAME"
>/tmp</TT
>.
</P
></DD
></DL
></DIV
><P
> This utility, like most other <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> utilities,
also uses the environment variables supported by <SPAN
CLASS="APPLICATION"
>libpq</SPAN
>
(see <A
HREF="libpq-envars.html"
>Section 30.12</A
>).
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN65798"
></A
><H2
>Files</H2
><P
></P
><UL
><LI
><P
> Before starting up, <SPAN
CLASS="APPLICATION"
>psql</SPAN
> attempts to
read and execute commands from the system-wide
<TT
CLASS="FILENAME"
>psqlrc</TT
> file and the user's
<TT
CLASS="FILENAME"
>~/.psqlrc</TT
> file.
(On Windows, the user's startup file is named
<TT
CLASS="FILENAME"
>%APPDATA%\postgresql\psqlrc.conf</TT
>.)
See <TT
CLASS="FILENAME"
><TT
CLASS="REPLACEABLE"
><I
>PREFIX</I
></TT
>/share/psqlrc.sample</TT
>
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 <TT
CLASS="COMMAND"
>\set
</TT
> and <TT
CLASS="COMMAND"
>SET</TT
> commands).
</P
></LI
><LI
><P
> Both the system-wide <TT
CLASS="FILENAME"
>psqlrc</TT
> file and the user's
<TT
CLASS="FILENAME"
>~/.psqlrc</TT
> file can be made version-specific
by appending a dash and the <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
release number, for example <TT
CLASS="FILENAME"
>~/.psqlrc-8.3.6</TT
>.
A matching version-specific file will be read in preference to a
non-version-specific file.
</P
></LI
><LI
><P
> The command-line history is stored in the file
<TT
CLASS="FILENAME"
>~/.psql_history</TT
>, or
<TT
CLASS="FILENAME"
>%APPDATA%\postgresql\psql_history</TT
> on Windows.
</P
></LI
></UL
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN65821"
></A
><H2
>Notes</H2
><P
></P
><UL
><LI
><P
> In an earlier life <SPAN
CLASS="APPLICATION"
>psql</SPAN
> allowed the
first argument of a single-letter backslash command to start
directly after the command, without intervening whitespace. 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:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\foo</KBD
>
Field separator is "oo".</PRE
><P>
which is perhaps not what one would expect.
</P
></LI
><LI
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> only works 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 different version.
</P
></LI
></UL
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN65832"
></A
><H2
>Notes for Windows users</H2
><P
> <SPAN
CLASS="APPLICATION"
>psql</SPAN
> is built as a <SPAN
CLASS="QUOTE"
>"console
application"</SPAN
>. 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 <SPAN
CLASS="APPLICATION"
>psql</SPAN
>.
If <SPAN
CLASS="APPLICATION"
>psql</SPAN
> detects a problematic
console code page, it will warn you at startup. To change the
console code page, two things are necessary:
<P
></P
></P><UL
><LI
><P
> Set the code page by entering <KBD
CLASS="USERINPUT"
>cmd.exe /c chcp
1252</KBD
>. (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 <TT
CLASS="FILENAME"
>/etc/profile</TT
>.
</P
></LI
><LI
><P
> Set the console font to <TT
CLASS="LITERAL"
>Lucida Console</TT
>, because the
raster font does not work with the ANSI code page.
</P
></LI
></UL
><P>
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="APP-PSQL-EXAMPLES"
></A
><H2
>Examples</H2
><P
> The first example shows how to spread a command over several lines of
input. Notice the changing prompt:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>CREATE TABLE my_table (</KBD
>
testdb(> <KBD
CLASS="USERINPUT"
> first integer not null default 0,</KBD
>
testdb(> <KBD
CLASS="USERINPUT"
> second text)</KBD
>
testdb-> <KBD
CLASS="USERINPUT"
>;</KBD
>
CREATE TABLE</PRE
><P>
Now look at the table definition again:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\d my_table</KBD
>
Table "my_table"
Attribute | Type | Modifier
-----------+---------+--------------------
first | integer | not null default 0
second | text | </PRE
><P>
Now we change the prompt to something more interesting:
</P><PRE
CLASS="PROGRAMLISTING"
>testdb=> <KBD
CLASS="USERINPUT"
>\set PROMPT1 '%n@%m %~%R%# '</KBD
>
peter@localhost testdb=></PRE
><P>
Let's assume you have filled the table with data and want to take a
look at it:
</P><PRE
CLASS="PROGRAMLISTING"
>peter@localhost testdb=> SELECT * FROM my_table;
first | second
-------+--------
1 | one
2 | two
3 | three
4 | four
(4 rows) </PRE
><P>
You can display tables in different ways by using the
<TT
CLASS="COMMAND"
>\pset</TT
> command:
</P><PRE
CLASS="PROGRAMLISTING"
>peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset border 2</KBD
>
Border style is 2.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>SELECT * FROM my_table;</KBD
>
+-------+--------+
| first | second |
+-------+--------+
| 1 | one |
| 2 | two |
| 3 | three |
| 4 | four |
+-------+--------+
(4 rows)
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset border 0</KBD
>
Border style is 0.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>SELECT * FROM my_table;</KBD
>
first second
----- ------
1 one
2 two
3 three
4 four
(4 rows)
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset border 1</KBD
>
Border style is 1.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset format unaligned</KBD
>
Output format is unaligned.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset fieldsep ","</KBD
>
Field separator is ",".
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\pset tuples_only</KBD
>
Showing only tuples.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>SELECT second, first FROM my_table;</KBD
>
one,1
two,2
three,3
four,4</PRE
><P>
Alternatively, use the short commands:
</P><PRE
CLASS="PROGRAMLISTING"
>peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>\a \t \x</KBD
>
Output format is aligned.
Tuples only is off.
Expanded display is on.
peter@localhost testdb=> <KBD
CLASS="USERINPUT"
>SELECT * FROM my_table;</KBD
>
-[ RECORD 1 ]-
first | 1
second | one
-[ RECORD 2 ]-
first | 2
second | two
-[ RECORD 3 ]-
first | 3
second | three
-[ RECORD 4 ]-
first | 4
second | four</PRE
><P>
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><A
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distrib
>
Mandriva
>
2008.1
>
x86_64
>
media
>
main-testing
>
by-pkgid
>
bab02a23fa9f3df8d66a9a3231b50245
>
files
>
26
