Psql documentation notes for windows users

a

If the current table output format is unaligned, it is switched to aligned.
If it is not unaligned, it is set to unaligned. This command is
kept for backwards compatibility. See

pset

for a
more general solution.

c

or

connect [ -reuse-previous=

on|off

] [

dbname

[

username

] [

host

] [

port

] |

conninfo

]

Establishes a new connection to a

PostgreSQL

server. The connection parameters to use can be specified either
using a positional syntax (one or more of database name, user,
host, and port), or using a

conninfo

connection string as detailed in

Section 32.1.1

. If no arguments are given, a
new connection is made using the same parameters as before.

Specifying any
of

dbname

,

username

,

host

or

port

as

—

is equivalent to omitting that parameter.

The new connection can re-use connection parameters from the previous
connection; not only database name, user, host, and port, but other
settings such as

sslmode

. By default,
parameters are re-used in the positional syntax, but not when
a

conninfo

string is given. Passing a
first argument of

-reuse-previous=on

or

-reuse-previous=off

overrides that default. If
parameters are re-used, then any parameter not explicitly specified as
a positional parameter or in the

conninfo

string is taken from the existing connection’s parameters. An
exception is that if the

host

setting
is changed from its previous value using the positional syntax,
any

hostaddr

setting present in the
existing connection’s parameters is dropped.
Also, any password used for the existing connection will be re-used
only if the user, host, and port settings are not changed.
When the command neither specifies nor reuses a particular parameter,
the

libpq

default is used.

If the new connection is successfully made, the previous
connection is closed.
If the connection attempt fails (wrong user name, access
denied, etc.), the previous connection will be kept if

psql

is in interactive mode. But 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.

Examples:

=> c mydb myuser host.dom 6432
=> c service=foo
=> c "host=localhost port=5432 dbname=mydb connect_timeout=10 sslmode=disable"
=> c -reuse-previous=on sslmode=require    -- changes only sslmode
=> c postgresql://tom@localhost/mydb?application_name=myapp

C [

title

]

Sets the title of any tables being printed as the result of a
query or unset any such title. This command is equivalent to

pset title

title

. (The name of
this command derives from

«caption»

, as it was
previously only used to set the caption in an

HTML

table.)

cd [

directory

]

Changes the current working directory to

directory

. Without argument, changes
to the current user’s home directory.

Tip:

To print your current working directory, use

! pwd

.

conninfo

Outputs information about the current database connection.

copy {

table

[ (

column_list

) ] | (

query

) }
{

from

|

to

}
{

‘filename’

| program

‘command’

| stdin | stdout | pstdin | pstdout }
[ [ with ] (

option

[, …] ) ]

Performs a frontend (client) copy. This is an operation that
runs an

SQL

COPY

command, but instead of the server
reading or writing the specified file,

psql

reads or writes the file and
routes the data between the server and the local file system.
This means that file accessibility and privileges are those of
the local user, not the server, and no SQL superuser
privileges are required.

When

program

is specified,

command

is
executed by

psql

and the data passed from
or to

command

is
routed between the server and the client.
Again, the execution privileges are those of
the local user, not the server, and no SQL superuser
privileges are required.

For

copy … from stdin

, data rows are read from the same
source that issued the command, continuing until

.

is read or the stream reaches

EOF

. This option is useful
for populating tables in-line within a SQL script file.
For

copy … to stdout

, output is sent to the same place
as

psql

command output, and
the

COPY

count

command status is
not printed (since it might be confused with a data row).
To read/write

psql

‘s standard input or
output regardless of the current command source or

o

option, write

from pstdin

or

to pstdout

.

The syntax of this command is similar to that of the

SQL

COPY

command. All options other than the data source/destination are
as specified for

COPY

.
Because of this, special parsing rules apply to the

copy

command. In particular,

psql

‘s variable substitution
rules and backslash escapes do not apply.

Tip:

Another way to obtain the same result as

copy
… to

is to use the

SQL

COPY
… TO STDOUT

command and terminate it
with

g

filename

or

g |

program

.
Unlike

copy

, this method allows the command to
span multiple lines; also, variable interpolation and backquote
expansion can be used.

Tip:

These operations are not as efficient as the

SQL

COPY

command with a file or program data source or
destination, because all data must pass through the client/server
connection. For large amounts of data the

SQL

command might be preferable.

copyright

Shows the copyright and distribution terms of

PostgreSQL

.

crosstabview [

colV

[

colH

[

colD

[

sortcolH

] ] ] ]

Executes the current query buffer (like

g

) and
shows the results in a crosstab grid.
The query must return at least three columns.
The output column identified by

colV

becomes a vertical header and the output column identified by

colH

becomes a horizontal header.

colD

identifies
the output column to display within the grid.

sortcolH

identifies
an optional sort column for the horizontal header.

Each column specification can be a column number (starting at 1) or
a column name. The usual SQL case folding and quoting rules apply to
column names. If omitted,

colV

is taken as column 1
and

colH

as column 2.

colH

must differ from

colV

.
If

colD

is not
specified, then there must be exactly three columns in the query
result, and the column that is neither

colV

nor

colH

is taken to be

colD

.

The vertical header, displayed as the leftmost column, contains the
values found in column

colV

, in the
same order as in the query results, but with duplicates removed.

The horizontal header, displayed as the first row, contains the values
found in column

colH

,
with duplicates removed. By default, these appear in the same order
as in the query results. But if the
optional

sortcolH

argument is given,
it identifies a column whose values must be integer numbers, and the
values from

colH

will
appear in the horizontal header sorted according to the
corresponding

sortcolH

values.

Inside the crosstab grid, for each distinct value

x

of

colH

and each distinct
value

y

of

colV

, the cell located
at the intersection

(x,y)

contains the value of
the

colD

column in the query result row for which
the value of

colH

is

x

and the value
of

colV

is

y

. If there is no such row, the cell is empty. If
there are multiple such rows, an error is reported.

d[S+] [

pattern

]

For each relation (table, view, materialized view, index, sequence,
or foreign table)
or composite type matching the

pattern

, show all
columns, their types, the tablespace (if not the default) and any
special attributes such as

NOT NULL

or defaults.
Associated indexes, constraints, rules, and triggers are
also shown. For foreign tables, the associated foreign
server is shown as well.
(

«Matching the pattern»

is defined in

Patterns

below.)

For some types of relation,

d

shows additional information
for each column: column values for sequences, indexed expressions for
indexes, and foreign data wrapper options for foreign tables.

The command form

d+

is identical, except that
more information is displayed: any comments associated with the
columns of the table are shown, as is the presence of OIDs in the
table, the view definition if the relation is a view, a non-default

replica
identity

setting.

By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.

Note:

If

d

is used without a

pattern

argument, it is
equivalent to

dtvmsE

which will show a list of
all visible tables, views, materialized views, sequences and
foreign tables.
This is purely a convenience measure.

da[S] [

pattern

]

Lists aggregate functions, together with their
return type and the data types they operate on. If

pattern

is specified, only aggregates whose names match the pattern are shown.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.

dA[+] [

pattern

]

Lists access methods. If

pattern

is specified, only access
methods whose names match the pattern are shown. If

+

is appended to the command name, each access
method is listed with its associated handler function and description.

db[+] [

pattern

]

Lists tablespaces. If

pattern

is specified, only tablespaces whose names match the pattern are shown.
If

+

is appended to the command name, each tablespace
is listed with its associated options, on-disk size, permissions and
description.

dc[S+] [

pattern

]

Lists conversions between character-set encodings.
If

pattern

is specified, only conversions whose names match the pattern are
listed.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.
If

+

is appended to the command name, each object
is listed with its associated description.

dC[+] [

pattern

]

Lists type casts.
If

pattern

is specified, only casts whose source or target types match the
pattern are listed.
If

+

is appended to the command name, each object
is listed with its associated description.

dd[S] [

pattern

]

Shows the descriptions of objects of type

constraint

,

operator class

,

operator family

,

rule

, and

trigger

. All
other comments may be viewed by the respective backslash commands for
those object types.

dd

displays descriptions for objects matching the

pattern

, or of visible
objects of the appropriate type if no argument is given. But in either
case, only objects that have a description are listed.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.

Descriptions for objects can be created with the

COMMENT

SQL

command.

ddp [

pattern

]

Lists default access privilege settings. An entry is shown for
each role (and schema, if applicable) for which the default
privilege settings have been changed from the built-in defaults.
If

pattern

is
specified, only entries whose role name or schema name matches
the pattern are listed.

The

ALTER DEFAULT PRIVILEGES

command is used to set
default access privileges. The meaning of the
privilege display is explained under

GRANT

.

dD[S+] [

pattern

]

Lists domains. If

pattern

is specified, only domains whose names match the pattern are shown.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.
If

+

is appended to the command name, each object
is listed with its associated permissions and description.

dE[S+] [

pattern

]

di[S+] [

pattern

]

dm[S+] [

pattern

]

ds[S+] [

pattern

]

dt[S+] [

pattern

]

dv[S+] [

pattern

]

In this group of commands, the letters

E

,

i

,

m

,

s

,

t

, and

v

stand for foreign table, index, materialized view, sequence, table, and view,
respectively.
You can specify any or all of
these letters, in any order, to obtain a listing of objects
of these types. For example,

dit

lists indexes
and tables. If

+

is
appended to the command name, each object is listed with its
physical size on disk and its associated description, if any.
If

pattern

is
specified, only objects whose names match the pattern are listed.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.

des[+] [

pattern

]

Lists foreign servers (mnemonic:

«external
servers»

).
If

pattern

is
specified, only those servers whose name matches the pattern
are listed. If the form

des+

is used, a
full description of each server is shown, including the
server’s ACL, type, version, options, and description.

det[+] [

pattern

]

Lists foreign tables (mnemonic:

«external tables»

).
If

pattern

is
specified, only entries whose table name or schema name matches
the pattern are listed. If the form

det+

is used, generic options and the foreign table description
are also displayed.

deu[+] [

pattern

]

Lists user mappings (mnemonic:

«external
users»

).
If

pattern

is
specified, only those mappings whose user names match the
pattern are listed. If the form

deu+

is
used, additional information about each mapping is shown.

Caution

deu+ might also display the user name and password of the remote user, so care should be taken not to disclose them.

dew[+] [

pattern

]

Lists foreign-data wrappers (mnemonic:

«external
wrappers»

).
If

pattern

is
specified, only those foreign-data wrappers whose name matches
the pattern are listed. If the form

dew+

is used, the ACL, options, and description of the foreign-data
wrapper are also shown.

df[antwS+] [

pattern

]

Lists functions, together with their result data types, argument data
types, and function types, which are classified as

«agg»

(aggregate),

«normal»

,

«trigger»

, or

«window»

.
To display only functions
of specific type(s), add the corresponding letters

a

,

n

,

t

, or

w

to the command.
If

pattern

is specified, only
functions whose names match the pattern are shown.
By default, only user-created
objects are shown; supply a pattern or the

S

modifier to include system objects.
If the form

df+

is used, additional information
about each function is shown, including volatility,
parallel safety, owner, security classification, access privileges,
language, source code and description.

Tip:

To look up functions taking arguments or returning values of a specific
data type, use your pager’s search capability to scroll through the

df

output.

dF[+] [

pattern

]

Lists text search configurations.
If

pattern

is specified,
only configurations whose names match the pattern are shown.
If the form

dF+

is used, a full description of
each configuration is shown, including the underlying text search
parser and the dictionary list for each parser token type.

dFd[+] [

pattern

]

Lists text search dictionaries.
If

pattern

is specified,
only dictionaries whose names match the pattern are shown.
If the form

dFd+

is used, additional information
is shown about each selected dictionary, including the underlying
text search template and the option values.

dFp[+] [

pattern

]

Lists text search parsers.
If

pattern

is specified,
only parsers whose names match the pattern are shown.
If the form

dFp+

is used, a full description of
each parser is shown, including the underlying functions and the
list of recognized token types.

dFt[+] [

pattern

]

Lists text search templates.
If

pattern

is specified,
only templates whose names match the pattern are shown.
If the form

dFt+

is used, additional information
is shown about each template, including the underlying function names.

dg[S+] [

pattern

]

Lists database roles.
(Since the concepts of

«users»

and

«groups»

have been
unified into

«roles»

, this command is now equivalent to

du

.)
By default, only user-created roles are shown; supply the

S

modifier to include system roles.
If

pattern

is specified,
only those roles whose names match the pattern are listed.
If the form

dg+

is used, additional information
is shown about each role; currently this adds the comment for each
role.

dl

This is an alias for

lo_list

, which shows a
list of large objects.

dL[S+] [

pattern

]

Lists procedural languages. If

pattern

is specified, only languages whose names match the pattern are listed.
By default, only user-created languages
are shown; supply the

S

modifier to include system
objects. If

+

is appended to the command name, each
language is listed with its call handler, validator, access privileges,
and whether it is a system object.

dn[S+] [

pattern

]

Lists schemas (namespaces). If

pattern

is specified, only schemas whose names match the pattern are listed.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system objects.
If

+

is appended to the command name, each object
is listed with its associated permissions and description, if any.

do[S+] [

pattern

]

Lists operators with their operand and result types.
If

pattern

is
specified, only operators whose names match the pattern are listed.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.
If

+

is appended to the command name,
additional information about each operator is shown, currently just
the name of the underlying function.

dO[S+] [

pattern

]

Lists collations.
If

pattern

is
specified, only collations whose names match the pattern are
listed. By default, only user-created objects are shown;
supply a pattern or the

S

modifier to
include system objects. If

+

is appended
to the command name, each collation is listed with its associated
description, if any.
Note that only collations usable with the current database’s encoding
are shown, so the results may vary in different databases of the
same installation.

dp [

pattern

]

Lists tables, views and sequences with their
associated access privileges.
If

pattern

is
specified, only tables, views and sequences whose names match the
pattern are listed.

The

GRANT

and

REVOKE

commands are used to set access privileges. The meaning of the
privilege display is explained under

GRANT

.

drds [

role-pattern

[

database-pattern

] ]

Lists defined configuration settings. These settings can be
role-specific, database-specific, or both.

role-pattern

and

database-pattern

are used to select
specific roles and databases to list, respectively. If omitted, or if

*

is specified, all settings are listed, including those
not role-specific or database-specific, respectively.

The

ALTER ROLE

and

ALTER DATABASE

commands are used to define per-role and per-database configuration
settings.

dT[S+] [

pattern

]

Lists data types.
If

pattern

is
specified, only types whose names match the pattern are listed.
If

+

is appended to the command name, each type is
listed with its internal name and size, its allowed values
if it is an

enum

type, and its associated permissions.
By default, only user-created objects are shown; supply a
pattern or the

S

modifier to include system
objects.

du[S+] [

pattern

]

Lists database roles.
(Since the concepts of

«users»

and

«groups»

have been
unified into

«roles»

, this command is now equivalent to

dg

.)
By default, only user-created roles are shown; supply the

S

modifier to include system roles.
If

pattern

is specified,
only those roles whose names match the pattern are listed.
If the form

du+

is used, additional information
is shown about each role; currently this adds the comment for each
role.

dx[+] [

pattern

]

Lists installed extensions.
If

pattern

is specified, only those extensions whose names match the pattern
are listed.
If the form

dx+

is used, all the objects belonging
to each matching extension are listed.

dy[+] [

pattern

]

Lists event triggers.
If

pattern

is specified, only those event triggers whose names match the pattern
are listed.
If

+

is appended to the command name, each object
is listed with its associated description.

e

or

edit

[

filename

] [

line_number

]

If

filename

is
specified, the file is edited; after the editor exits, its
content is copied back to the query buffer. If no

filename

is given, the current query
buffer is copied to a temporary file which is then edited in the same
fashion.

The new query buffer is then re-parsed according to the normal
rules of

psql

, where the whole buffer
is treated as a single line. (Thus you cannot make scripts this
way. Use

i

for that.) This means that
if the query ends with (or contains) a semicolon, it is
immediately executed. Otherwise it will merely wait in the
query buffer; type semicolon or

g

to send it, or

r

to cancel.

If a line number is specified,

psql

will
position the cursor on the specified line of the file or query buffer.
Note that if a single all-digits argument is given,

psql

assumes it is a line number,
not a file name.

Tip:

See under

Environment

for how to configure and
customize your editor.

echo

text

[ … ]

Prints the arguments to the standard output, separated by one
space and followed by a newline. This can be useful to
intersperse information in the output of scripts. For example:

=> echo `date`
Tue Oct 26 21:40:57 CEST 1999

If the first argument is an unquoted

-n

the trailing
newline is not written.

Tip:

If you use the

o

command to redirect your
query output you might wish to use

qecho

instead of this command.

ef [

function_description

[

line_number

]

]

This command fetches and edits the definition of the named function,
in the form of a

CREATE OR REPLACE FUNCTION

command.
Editing is done in the same way as for

edit

.
After the editor exits, the updated command waits in the query buffer;
type semicolon or

g

to send it, or

r

to cancel.

The target function can be specified by name alone, or by name
and arguments, for example

foo(integer, text)

.
The argument types must be given if there is more
than one function of the same name.

If no function is specified, a blank

CREATE FUNCTION

template is presented for editing.

If a line number is specified,

psql

will
position the cursor on the specified line of the function body.
(Note that the function body typically does not begin on the first
line of the file.)

Tip:

See under

Environment

for how to configure and
customize your editor.

encoding [

encoding

]

Sets the client character set encoding. Without an argument, this command
shows the current encoding.

errverbose

Repeats the most recent server error message at maximum
verbosity, as though

VERBOSITY

were set
to

verbose

and

SHOW_CONTEXT

were
set to

always

.

ev [

view_name

[

line_number

]

]

This command fetches and edits the definition of the named view,
in the form of a

CREATE OR REPLACE VIEW

command.
Editing is done in the same way as for

edit

.
After the editor exits, the updated command waits in the query buffer;
type semicolon or

g

to send it, or

r

to cancel.

If no view is specified, a blank

CREATE VIEW

template is presented for editing.

If a line number is specified,

psql

will
position the cursor on the specified line of the view definition.

f [

string

]

Sets the field separator for unaligned query output. The default
is the vertical bar (

|

). See also

pset

for a generic way of setting output
options.

g [

filename

]

g [ |

command

]

Sends the current query input buffer to the server, and
optionally stores the query’s output in

filename

or pipes the output
to the shell command

command

. The file or command is
written to only if the query successfully returns zero or more tuples,
not if the query fails or is a non-data-returning SQL command.

A bare

g

is essentially equivalent to a semicolon.
A

g

with argument is a

«one-shot»

alternative to the

o

command.

gexec

Sends the current query input buffer to the server, then treats
each column of each row of the query’s output (if any) as a SQL
statement to be executed. For example, to create an index on each
column of

my_table

:

=> SELECT format('create index on my_table(%I)', attname)
-> FROM pg_attribute
-> WHERE attrelid = 'my_table'::regclass AND attnum > 0
-> ORDER BY attnum
-> gexec
CREATE INDEX
CREATE INDEX
CREATE INDEX
CREATE INDEX

The generated queries are executed in the order in which the rows
are returned, and left-to-right within each row if there is more
than one column. NULL fields are ignored. The generated queries
are sent literally to the server for processing, so they cannot be

psql

meta-commands nor contain

psql

variable references. If any individual query fails, execution of
the remaining queries continues
unless

ON_ERROR_STOP

is set. Execution of each
query is subject to

ECHO

processing.
(Setting

ECHO

to

all

or

queries

is often advisable when
using

gexec

.) Query logging, single-step mode,
timing, and other query execution features apply to each generated
query as well.

gset [

prefix

]

Sends the current query input buffer to the server and stores the
query’s output into

psql

variables (see

Variables

).
The query to be executed must return exactly one row. Each column of
the row is stored into a separate variable, named the same as the
column. For example:

=> SELECT 'hello' AS var1, 10 AS var2
-> gset
=> echo :var1 :var2
hello 10

If you specify a

prefix

,
that string is prepended to the query’s column names to create the
variable names to use:

=> SELECT 'hello' AS var1, 10 AS var2
-> gset result_
=> echo :result_var1 :result_var2
hello 10

If a column result is NULL, the corresponding variable is unset
rather than being set.

If the query fails or does not return one row,
no variables are changed.

h

or

help

[

command

]

Gives syntax help on the specified

SQL

command. If

command

is not specified, then

psql

will list
all the commands for which syntax help is available. If

command

is an
asterisk (

*

), then syntax help on all

SQL

commands is shown.

Note:

To simplify typing, commands that consists of several words do
not have to be quoted. Thus it is fine to type

help
alter table

.

H

or

html

Turns on

HTML

query output format. If the

HTML

format is already on, it is switched
back to the default aligned text format. This command is for
compatibility and convenience, but see

pset

about setting other output options.

i

or

include

filename

Reads input from the file

filename

and executes it as
though it had been typed on the keyboard.

If

filename

is

—

(hyphen), then standard input is read until an EOF indication
or

q

meta-command. This can be used to intersperse
interactive input with input from files. Note that Readline behavior
will be used only if it is active at the outermost level.

Note:

If you want to see the lines on the screen as they are read you
must set the variable

ECHO

to

all

.

ir

or

include_relative

filename

The

ir

command is similar to

i

, but resolves
relative file names differently. When executing in interactive mode,
the two commands behave identically. However, when invoked from a
script,

ir

interprets file names relative to the
directory in which the script is located, rather than the current
working directory.

l[+]

or

list[+] [

pattern

]

List the databases in the server and show their names, owners,
character set encodings, and access privileges.
If

pattern

is specified,
only databases whose names match the pattern are listed.
If

+

is appended to the command name, database
sizes, default tablespaces, and descriptions are also displayed.
(Size information is only available for databases that the current
user can connect to.)

lo_export

loid

filename

Reads the large object with

OID

loid

from the database and
writes it to

filename

. Note that this is
subtly different from the server function

lo_export

, which acts with the permissions
of the user that the database server runs as and on the server’s
file system.

Tip:

Use

lo_list

to find out the large object’s

OID

.

lo_import

filename

[

comment

]

Stores the file into a

PostgreSQL

large object. Optionally, it associates the given
comment with the object. Example:

foo=> lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'
lo_import 152801

The response indicates that the large object received object
ID 152801, which can be used to access the newly-created large
object in the future. For the sake of readability, it is
recommended to always associate a human-readable comment with
every object. Both OIDs and comments can be viewed with the

lo_list

command.

Note that this command is subtly different from the server-side

lo_import

because it acts as the local user
on the local file system, rather than the server’s user and file
system.

lo_list

Shows a list of all

PostgreSQL

large objects currently stored in the database,
along with any comments provided for them.

lo_unlink

loid

Deletes the large object with

OID

loid

from the
database.

Tip:

Use

lo_list

to find out the large object’s

OID

.

o

or

out [

filename

]

o

or

out [ |

command

]

Arranges to save future query results to the file

filename

or pipe future results
to the shell command

command

. If no argument is
specified, the query output is reset to the standard output.

«Query results»

includes all tables, command
responses, and notices obtained from the database server, as
well as output of various backslash commands that query the
database (such as

d

), but not error
messages.

Tip:

To intersperse text output in between query results, use

qecho

.

p

or

print

Print the current query buffer to the standard output.

password [

username

]

Changes the password of the specified user (by default, the current
user). This command prompts for the new password, encrypts it, and
sends it to the server as an

ALTER ROLE

command. This
makes sure that the new password does not appear in cleartext in the
command history, the server log, or elsewhere.

prompt [

text

]

name

Prompts the user to supply text, which is assigned to the variable

name

.
An optional prompt string,

text

, can be specified. (For multiword
prompts, surround the text with single quotes.)

By default,

prompt

uses the terminal for input and
output. However, if the

-f

command line switch was
used,

prompt

uses standard input and standard output.

pset [

option

[

value

] ]

This command sets options affecting the output of query result tables.

option

indicates which option is to be set. The semantics of

value

vary depending
on the selected option. For some options, omitting

value

causes the option to be toggled
or unset, as described under the particular option. If no such
behavior is mentioned, then omitting

value

just results in
the current setting being displayed.

pset

without any arguments displays the current status
of all printing options.

Adjustable printing options are:

border

The

value

must be a
number. In general, the higher
the number the more borders and lines the tables will have,
but details depend on the particular format.
In

HTML

format, this will translate directly
into the

border=…

attribute.
In most other formats only values 0 (no border), 1 (internal
dividing lines), and 2 (table frame) make sense, and values above 2
will be treated the same as

border = 2

.
The

latex

and

latex-longtable

formats additionally allow a value of 3 to add dividing lines
between data rows.

columns

Sets the target width for the

wrapped

format, and also
the width limit for determining whether output is wide enough to
require the pager or switch to the vertical display in expanded auto
mode.
Zero (the default) causes the target width to be controlled by the
environment variable

COLUMNS

, or the detected screen width
if

COLUMNS

is not set.
In addition, if

columns

is zero then the

wrapped

format only affects screen output.
If

columns

is nonzero then file and pipe output is
wrapped to that width as well.

expanded

(or

x

)

If

value

is specified it
must be either

on

or

off

, which
will enable or disable expanded mode, or

auto

.
If

value

is omitted the
command toggles between the on and off settings. When expanded mode
is enabled, query results are displayed in two columns, with the
column name on the left and the data on the right. This mode is
useful if the data wouldn’t fit on the screen in the
normal

«horizontal»

mode. In the auto setting, the
expanded mode is used whenever the query output has more than one
column and is wider than the screen; otherwise, the regular mode is
used. The auto setting is only
effective in the aligned and wrapped formats. In other formats, it
always behaves as if the expanded mode is off.

fieldsep

Specifies the field separator to be used in unaligned output
format. That way one can create, for example, tab- or
comma-separated output, which other programs might prefer. To
set a tab as field separator, type

pset fieldsep
‘t’

. The default field separator is

‘|’

(a vertical bar).

fieldsep_zero

Sets the field separator to use in unaligned output format to a zero
byte.

footer

If

value

is specified
it must be either

on

or

off

which will enable or disable display of the table footer
(the

(

n

rows)

count).
If

value

is omitted the
command toggles footer display on or off.

format

Sets the output format to one of

unaligned

,

aligned

,

wrapped

,

html

,

asciidoc

,

latex

(uses

tabular

),

latex-longtable

, or

troff-ms

.
Unique abbreviations are allowed.

unaligned

format writes all columns of a row on one
line, separated by the currently active field separator. This
is useful for creating output that might be intended to be read
in by other programs (for example, tab-separated or comma-separated
format).

aligned

format is the standard, human-readable,
nicely formatted text output; this is the default.

wrapped

format is like

aligned

but wraps
wide data values across lines to make the output fit in the target
column width. The target width is determined as described under
the

columns

option. Note that

psql

will
not attempt to wrap column header titles; therefore,

wrapped

format behaves the same as

aligned

if the total width needed for column headers exceeds the target.

The

html

,

asciidoc

,

latex

,

latex-longtable

, and

troff-ms

formats put out tables that are intended to
be included in documents using the respective mark-up
language. They are not complete documents! This might not be
necessary in

HTML

, but in

LaTeX

you must have a complete
document wrapper.

latex-longtable

also requires the

LaTeX

longtable

and

booktabs

packages.

linestyle

Sets the border line drawing style to one
of

ascii

,

old-ascii

,
or

unicode

.
Unique abbreviations are allowed. (That would mean one
letter is enough.)
The default setting is

ascii

.
This option only affects the

aligned

and

wrapped

output formats.

ascii

style uses plain

ASCII

characters. Newlines in data are shown using
a

+

symbol in the right-hand margin.
When the

wrapped

format wraps data from
one line to the next without a newline character, a dot
(

.

) is shown in the right-hand margin of the first line,
and again in the left-hand margin of the following line.

old-ascii

style uses plain

ASCII

characters, using the formatting style used
in

PostgreSQL

8.4 and earlier.
Newlines in data are shown using a

:

symbol in place of the left-hand column separator.
When the data is wrapped from one line
to the next without a newline character, a

;

symbol is used in place of the left-hand column separator.

unicode

style uses Unicode box-drawing characters.
Newlines in data are shown using a carriage return symbol
in the right-hand margin. When the data is wrapped from one line
to the next without a newline character, an ellipsis symbol
is shown in the right-hand margin of the first line, and
again in the left-hand margin of the following line.

When the

border

setting is greater than zero,
the

linestyle

option also determines the
characters with which the border lines are drawn.
Plain

ASCII

characters work everywhere, but
Unicode characters look nicer on displays that recognize them.

null

Sets the string to be printed in place of a null value.
The default is to print nothing, which can easily be mistaken for
an empty string. For example, one might prefer

pset null
‘(null)’

.

numericlocale

If

value

is specified
it must be either

on

or

off

which will enable or disable display of a locale-specific character
to separate groups of digits to the left of the decimal marker.
If

value

is omitted the
command toggles between regular and locale-specific numeric output.

pager

Controls use of a pager program for query and

psql

help output. If the environment variable

PAGER

is set, the output is piped to the specified program.
Otherwise a platform-dependent default (such as

more

) is used.

When the

pager

option is

off

, the pager
program is not used. When the

pager

option is

on

, the pager is used when appropriate, i.e., when the
output is to a terminal and will not fit on the screen.
The

pager

option can also be set to

always

,
which causes the pager to be used for all terminal output regardless
of whether it fits on the screen.

pset pager

without a

value

toggles pager use on and off.

pager_min_lines

If

pager_min_lines

is set to a number greater than the
page height, the pager program will not be called unless there are
at least this many lines of output to show. The default setting
is 0.

recordsep

Specifies the record (line) separator to use in unaligned
output format. The default is a newline character.

recordsep_zero

Sets the record separator to use in unaligned output format to a zero
byte.

tableattr

(or

T

)

In

HTML

format, this specifies attributes
to be placed inside the

table

tag. This
could for example be

cellpadding

or

bgcolor

. Note that you probably don’t want
to specify

border

here, as that is already
taken care of by

pset border

.
If no

value

is given,
the table attributes are unset.

In

latex-longtable

format, this controls
the proportional width of each column containing a left-aligned
data type. It is specified as a whitespace-separated list of values,
e.g.,

‘0.2 0.2 0.6’

. Unspecified output columns
use the last specified value.

title

(or

C

)

Sets the table title for any subsequently printed tables. This
can be used to give your output descriptive tags. If no

value

is given,
the title is unset.

tuples_only

(or

t

)

If

value

is specified
it must be either

on

or

off

which will enable or disable tuples-only mode.
If

value

is omitted the
command toggles between regular and tuples-only output.
Regular output includes extra information such
as column headers, titles, and various footers. In tuples-only
mode, only actual table data is shown.

unicode_border_linestyle

Sets the border drawing style for the

unicode

line style to one of

single

or

double

.

unicode_column_linestyle

Sets the column drawing style for the

unicode

line style to one of

single

or

double

.

unicode_header_linestyle

Sets the header drawing style for the

unicode

line style to one of

single

or

double

.

Illustrations of how these different formats look can be seen in
the

Examples

section.

Tip:

There are various shortcut commands for

pset

. See

a

,

C

,

f

,

H

,

t

,

T

,
and

x

.

q

or

quit

Quits the

psql

program.
In a script file, only execution of that script is terminated.

qecho

text

[ … ]

This command is identical to

echo

except
that the output will be written to the query output channel, as
set by

o

.

r

or

reset

Resets (clears) the query buffer.

s [

filename

]

Print

psql

‘s command line history
to

filename

.
If

filename

is omitted,
the history is written to the standard output (using the pager if
appropriate). This command is not available
if

psql

was built
without

Readline

support.

set [

name

[

value

[ … ] ] ]

Sets the

psql

variable

name

to

value

, or if more than one value
is given, to the concatenation of all of them. If only one
argument is given, the variable is set with an empty value. To
unset a variable, use the

unset

command.

set

without any arguments displays the names and values
of all currently-set

psql

variables.

Valid variable names can contain letters, digits, and
underscores. See the section

Variables

below for details.
Variable names are case-sensitive.

Although you are welcome to set any variable to anything you
want,

psql

treats several variables
as special. They are documented in the section about variables.

Note:

This command is unrelated to the

SQL

command

SET

.

setenv

name

[

value

]

Sets the environment variable

name

to

value

, or if the

value

is
not supplied, unsets the environment variable. Example:

testdb=> setenv PAGER less
testdb=> setenv LESS -imx4F

sf[+]

function_description

This command fetches and shows the definition of the named function,
in the form of a

CREATE OR REPLACE FUNCTION

command.
The definition is printed to the current query output channel,
as set by

o

.

The target function can be specified by name alone, or by name
and arguments, for example

foo(integer, text)

.
The argument types must be given if there is more
than one function of the same name.

If

+

is appended to the command name, then the
output lines are numbered, with the first line of the function body
being line 1.

sv[+]

view_name

This command fetches and shows the definition of the named view,
in the form of a

CREATE OR REPLACE VIEW

command.
The definition is printed to the current query output channel,
as set by

o

.

If

+

is appended to the command name, then the
output lines are numbered from 1.

t

Toggles the display of output column name headings and row count
footer. This command is equivalent to

pset
tuples_only

and is provided for convenience.

T

table_options

Specifies attributes to be placed within the

table

tag in

HTML

output format. This command is equivalent to

pset
tableattr

table_options

.

timing [

on

|

off

]

Without parameter, toggles a display of how long each SQL statement
takes, in milliseconds. With parameter, sets same.

unset

name

Unsets (deletes) the

psql

variable

name

.

w

or

write

filename

w

or

write

|

command

Outputs the current query buffer to the file

filename

or pipes it to the shell
command

command

.

watch [

seconds

]

Repeatedly execute the current query buffer (as

g

does)
until interrupted or the query fails. Wait the specified number of
seconds (default 2) between executions. Each query result is
displayed with a header that includes the

pset title

string (if any), the time as of query start, and the delay interval.

x [

on

|

off

|

auto

]

Sets or toggles expanded table formatting mode. As such it is equivalent to

pset expanded

.

z [

pattern

]

Lists tables, views and sequences with their
associated access privileges.
If a

pattern

is
specified, only tables, views and sequences whose names match the
pattern are listed.

This is an alias for

dp

(

«display
privileges»

).

! [

command

]

Escapes to a separate shell or executes the shell command

command

. The
arguments are not further interpreted; the shell will see them
as-is. In particular, the variable substitution rules and
backslash escapes do not apply.

? [

topic

]

Shows help information. The optional

topic

parameter
(defaulting to

commands

) selects which part of

psql

is
explained:

commands

describes

psql

‘s
backslash commands;

options

describes the command-line
options that can be passed to

psql

;
and

variables

shows help about

psql

configuration
variables.

Patterns

The various

d

commands accept a

pattern

parameter to specify the
object name(s) to be displayed. In the simplest case, a pattern
is just the exact name of the object. The characters within a
pattern are normally folded to lower case, just as in SQL names;
for example,

dt FOO

will display the table named

foo

. As in SQL names, placing double quotes around
a pattern stops folding to lower case. Should you need to include
an actual double quote character in a pattern, write it as a pair
of double quotes within a double-quote sequence; again this is in
accord with the rules for SQL quoted identifiers. For example,

dt «FOO»»BAR»

will display the table named

FOO»BAR

(not

foo»bar

). Unlike the normal
rules for SQL names, you can put double quotes around just part
of a pattern, for instance

dt FOO»FOO»BAR

will display
the table named

fooFOObar

.

Whenever the

pattern

parameter
is omitted completely, the

d

commands display all objects
that are visible in the current schema search path — this is
equivalent to using

*

as the pattern.
(An object is said to be

visible

if its
containing schema is in the search path and no object of the same
kind and name appears earlier in the search path. This is equivalent to the
statement that the object can be referenced by name without explicit
schema qualification.)
To see all objects in the database regardless of visibility,
use

*.*

as the pattern.

Within a pattern,

*

matches any sequence of characters
(including no characters) and

?

matches any single character.
(This notation is comparable to Unix shell file name patterns.)
For example,

dt int*

displays tables whose names
begin with

int

. But within double quotes,

*

and

?

lose these special meanings and are just matched
literally.

A pattern that contains a dot (

.

) is interpreted as a schema
name pattern followed by an object name pattern. For example,

dt foo*.*bar*

displays all tables whose table name
includes

bar

that are in schemas whose schema name
starts with

foo

. When no dot appears, then the pattern
matches only objects that are visible in the current schema search path.
Again, a dot within double quotes loses its special meaning and is matched
literally.

Advanced users can use regular-expression notations such as character
classes, for example

[0-9]

to match any digit. All regular
expression special characters work as specified in

Section 9.7.3

, except for

.

which
is taken as a separator as mentioned above,

*

which is
translated to the regular-expression notation

.*

,

?

which is translated to

.

, and

$

which is matched literally. You can emulate
these pattern characters at need by writing

?

for

.

,

(

R

+|)

for

R

*

, or

(

R

|)

for

R

?

.

$

is not needed as a regular-expression character since
the pattern must match the whole name, unlike the usual
interpretation of regular expressions (in other words,

$

is automatically appended to your pattern). Write

*

at the
beginning and/or end if you don’t wish the pattern to be anchored.
Note that within double quotes, all regular expression special characters
lose their special meanings and are matched literally. Also, the regular
expression special characters are matched literally in operator name
patterns (i.e., the argument of

do

).

Variables

psql

provides variable substitution
features similar to common Unix command shells.
Variables are simply name/value pairs, where the value
can be any string of any length. The name must consist of letters
(including non-Latin letters), digits, and underscores.

To set a variable, use the

psql

meta-command

set

. For example,

testdb=> set foo bar

sets the variable

foo

to the value

bar

. To retrieve the content of the variable, precede
the name with a colon, for example:

testdb=> echo :foo
bar

This works in both regular SQL commands and meta-commands; there is
more detail in

SQL

Interpolation

, below.

If you call

set

without a second argument, the
variable is set, with an empty string as value. To unset (i.e., delete)
a variable, use the command

unset

. To show the
values of all variables, call

set

without any argument.

A number of these variables are treated specially
by

psql

. They represent certain option
settings that can be changed at run time by altering the value of
the variable, or in some cases represent changeable state of

psql

. Although
you can use these variables for other purposes, this is not
recommended, as the program behavior might grow really strange
really quickly. By convention, all specially treated variables’ names
consist of all upper-case ASCII letters (and possibly digits and
underscores). To ensure maximum compatibility in the future, avoid
using such variable names for your own purposes. A list of all specially
treated variables follows.

SQL

Interpolation

A key feature of

psql

variables is that you can substitute (

«interpolate»

)
them into regular

SQL

statements, as well as the
arguments of meta-commands. Furthermore,

psql

provides facilities for
ensuring that variable values used as SQL literals and identifiers are
properly quoted. The syntax for interpolating a value without
any quoting is to prepend the variable name with a colon
(

:

). For example,

testdb=> set foo 'my_table'
testdb=> SELECT * FROM :foo;

would query the table

my_table

. Note that this
may be unsafe: the value of the variable is copied literally, so it can
contain unbalanced quotes, or even backslash commands. You must make sure
that it makes sense where you put it.

When a value is to be used as an SQL literal or identifier, it is
safest to arrange for it to be quoted. To quote the value of
a variable as an SQL literal, write a colon followed by the variable
name in single quotes. To quote the value as an SQL identifier, write
a colon followed by the variable name in double quotes.
These constructs deal correctly with quotes and other special
characters embedded within the variable value.
The previous example would be more safely written this way:

testdb=> set foo 'my_table'
testdb=> SELECT * FROM :"foo";

Variable interpolation will not be performed within quoted

SQL

literals and identifiers. Therefore, a
construction such as

‘:foo’

doesn’t work to produce a quoted
literal from a variable’s value (and it would be unsafe if it did work,
since it wouldn’t correctly handle quotes embedded in the value).

One example use of this mechanism is to
copy the contents of a file into a table column.
First load the file into a variable and then interpolate the variable’s
value as a quoted string:

testdb=> set content `cat my_file.txt`
testdb=> INSERT INTO my_table VALUES (:'content');

(Note that this still won’t work if

my_file.txt

contains NUL bytes.

psql

does not support embedded NUL bytes in variable values.)

Since colons can legally appear in SQL commands, an apparent attempt
at interpolation (that is,

:name

,

:’name’

, or

:»name»

) is not
replaced unless the named variable is currently set. In any case, you
can escape a colon with a backslash to protect it from substitution.

The colon syntax for variables is standard

SQL

for
embedded query languages, such as

ECPG

.
The colon syntaxes for array slices and type casts are

PostgreSQL

extensions, which can sometimes
conflict with the standard usage. The colon-quote syntax for escaping a
variable’s value as an SQL literal or identifier is a

psql

extension.

Prompting

The prompts

psql

issues can be customized
to your preference. The three variables

PROMPT1

,

PROMPT2

, and

PROMPT3

contain strings
and special escape sequences that describe the appearance of the
prompt. Prompt 1 is the normal prompt that is issued when

psql

requests a new command. Prompt 2 is
issued when more input is expected during command entry, for example
because the command was not terminated with a semicolon or a quote
was not closed.
Prompt 3 is issued when you are running an

SQL

COPY FROM STDIN

command and you need to type in
a row value on the terminal.

The value of the selected prompt variable is printed literally,
except where a percent sign (

%

) is encountered.
Depending on the next character, certain other text is substituted
instead. Defined substitutions are:

To insert a percent sign into your prompt, write

%%

. The default prompts are

‘%/%R%# ‘

for prompts 1 and 2, and

‘>> ‘

for prompt 3.

Command-Line Editing

psql

supports the

Readline

library for convenient line editing and retrieval. The command
history is automatically saved when

psql

exits and is reloaded when

psql

starts up. Tab-completion is also
supported, although the completion logic makes no claim to be an

SQL

parser. The queries generated by tab-completion
can also interfere with other SQL commands, e.g.,

SET
TRANSACTION ISOLATION LEVEL

.
If for some reason you do not like the tab completion, you
can turn it off by putting this in a file named

.inputrc

in your home directory:

$if psql
set disable-completion on
$endif

(This is not a

psql

but a

Readline

feature. Read its documentation
for further details.)