psql
psql —PostgreSQL interactive terminal
Synopsis
psql [option...] [dbname [username]]
Description
psql is a terminal-based front-end toPostgreSQL. It enables you to type in queries interactively, issue them toPostgreSQL, and see the query results. Alternatively, input can be from a file or from command line arguments. In addition,psql provides a number of meta-commands and various shell-like features to facilitate writing scripts and automating a wide variety of tasks.
Options
-a--echo-allPrint all nonempty input lines to standard output as they are read. (This does not apply to lines read interactively.) This is equivalent to setting the variable
ECHOtoall.-A--no-alignSwitches to unaligned output mode. (The default output mode is otherwise aligned.)
-b--echo-errorsPrint failed SQL commands to standard error output. This is equivalent to setting the variable
ECHOtoerrors.-ccommand--command=commandSpecifies thatpsql is to execute the given command string,
command. This option can be repeated and combined in any order with the-foption. When either-cor-fis specified,psql does not read commands from standard input; instead it terminates after processing all the-cand-foptions in sequence.commandmust be either a command string that is completely parsable by the server (i.e., it contains nopsql-specific features), or a single backslash command. Thus you cannot mixSQL andpsql meta-commands within a-coption. To achieve that, you could use repeated-coptions or pipe the string intopsql, for example:psql -c '\x' -c 'SELECT * FROM foo;'
or
echo '\x \\ SELECT * FROM foo;' | psql
(
\\is the separator meta-command.)EachSQL command string passed to
-cis sent to the server as a single query. Because of this, the server executes it as a single transaction even if the string contains multipleSQL commands, unless there are explicitBEGIN/COMMITcommands included in the string to divide it into multiple transactions. Also,psql only prints the result of the lastSQL command in the string. This is different from the behavior when the same string is read from a file or fed topsql's standard input, because thenpsql sends eachSQL command separately.Because of this behavior, putting more than one command in a single
-cstring often has unexpected results. It's better to use repeated-ccommands or feed multiple commands topsql's standard input, either usingecho as illustrated above, or via a shell here-document, for example:psql <<EOF\xSELECT * FROM foo;EOF
-ddbname--dbname=dbnameSpecifies the name of the database to connect to. This is equivalent to specifying
dbnameas the first non-option argument on the command line. Thedbnamecan be aconnection string. If so, connection string parameters will override any conflicting command line options.-e--echo-queriesCopy all SQL commands sent to the server to standard output as well. This is equivalent to setting the variable
ECHOtoqueries.-E--echo-hiddenEcho the actual queries generated by
\dand other backslash commands. You can use this to studypsql's internal operations. This is equivalent to setting the variableECHO_HIDDENtoon.-ffilename--file=filenameRead commands from the file
filename, rather than standard input. This option can be repeated and combined in any order with the-coption. When either-cor-fis specified,psql does not read commands from standard input; instead it terminates after processing all the-cand-foptions in sequence. Except for that, this option is largely equivalent to the meta-command\i.If
filenameis-(hyphen), then standard input is read until an EOF indication or\qmeta-command. This can be used to intersperse interactive input with input from files. Note however that Readline is not used in this case (much as if-nhad been specified).Using this option is subtly different from writing
psql <. In general, both will do what you expect, but usingfilename-fenables some nice features such as error messages with line numbers. There is also a slight chance that using this option will reduce the start-up overhead. On the other hand, the variant using the shell's input redirection is (in theory) guaranteed to yield exactly the same output you would have received had you entered everything by hand.-Fseparator--field-separator=separatorUse
separatoras the field separator for unaligned output. This is equivalent to\pset fieldsepor\f.-hhostname--host=hostnameSpecifies the host name of the machine on which the server is running. If the value begins with a slash, it is used as the directory for the Unix-domain socket.
-H--htmlTurn onHTML tabular output. This is equivalent to
\pset format htmlor the\Hcommand.-l--listList all available databases, then exit. Other non-connection options are ignored. This is similar to the meta-command
\list.-Lfilename--log-file=filenameWrite all query output into file
filename, in addition to the normal output destination.-n--no-readlineDo not useReadline for line editing and do not use the command history. This can be useful to turn off tab expansion when cutting and pasting.
-ofilename--output=filenamePut all query output into file
filename. This is equivalent to the command\o.-pport--port=portSpecifies 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
PGPORTenvironment variable or, if not set, to the port specified at compile time, usually 5432.-Passignment--pset=assignmentSpecifies printing options, in the style of
\pset. Note that here you have to separate name and value with an equal sign instead of a space. For example, to set the output format toLaTeX, you could write-P format=latex.-q--quietSpecifies thatpsql 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
-coption. This is equivalent to setting the variableQUIETtoon.-Rseparator--record-separator=separatorUse
separatoras the record separator for unaligned output. This is equivalent to the\pset recordsepcommand.-s--single-stepRun in single-step mode. That means the user is prompted before each command is sent to the server, with the option to cancel execution as well. Use this to debug scripts.
-S--single-lineRuns in single-line mode where a newline terminates an SQL command, as a semicolon does.
Note
This mode is provided for those who insist on it, but you are not necessarily encouraged to use it. In particular, if you mixSQL and meta-commands on a line the order of execution might not always be clear to the inexperienced user.
-t--tuples-onlyTurn off printing of column names and result row count footers, etc. This is equivalent to the
\tcommand.-Ttable_options--table-attr=table_options
Exit Status
psql returns 0 to the shell if it finished normally, 1 if a fatal error of its own occurs (e.g., out of memory, file not found), 2 if the connection to the server went bad and the session was not interactive, and 3 if an error occurred in a script and the variableON_ERROR_STOP was set.
Usage
Connecting to a Database
psql is a regularPostgreSQL client application. In order to connect to a database you need to know the name of your target database, the host name and port number of the server, and what user name you want to connect as.psql can be told about those parameters via command line options, namely-d,-h,-p, and-U respectively. If an argument is found that does not belong to any option it will be interpreted as the database name (or the user name, if the database name is already given). Not all of these options are required; there are useful defaults. If you omit the host name,psql will connect via a Unix-domain socket to a server on the local host, or via TCP/IP tolocalhost 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 operating-system user name, as is the default database name. Note that you cannot just connect to any database under any user name. Your database administrator should have informed you about your access rights.
When the defaults aren't quite right, you can save yourself some typing by setting the environment variablesPGDATABASE,PGHOST,PGPORT and/orPGUSER to appropriate values. (For additional environment variables, seeSection 32.14.) It is also convenient to have a~/.pgpass file to avoid regularly having to type in passwords. SeeSection 32.15 for more information.
An alternative way to specify connection parameters is in a This way you can also useLDAP for connection parameter lookup as described inSection 32.17. SeeSection 32.1.2 for more information on all the available connection options. If the connection could not be made for any reason (e.g., insufficient privileges, server is not running on the targeted host, etc.),psql will return an error and terminate. If both standard input and standard output are a terminal, thenpsql sets the client encoding to“auto”, which will detect the appropriate client encoding from the locale settings (conninfo string or aURI, which is used instead of a database name. This mechanism give you very wide control over the connection. For example:$
psql "service=myservice sslmode=require"$psql postgresql://dbmaster:5433/mydb?sslmode=requireLC_CTYPE environment variable on Unix systems). If this doesn't work out as expected, the client encoding can be overridden using the environment variablePGCLIENTENCODING.
Entering SQL Commands
In normal operation,psql provides a prompt with the name of the database to whichpsql is currently connected, followed by the string=>. For example:
$psql testdbpsql (9.6.24)Type "help" for help.testdb=> At the prompt, the user can type inSQL 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. If untrusted users have access to a database that has not adopted asecure schema usage pattern, begin your session by removing publicly-writable schemas from Whenever a command is executed,psql also polls for asynchronous notification events generated byLISTEN andNOTIFY. While C-style block comments are passed to the server for processing and removal, SQL-standard comments are removed bypsql.search_path. One can addoptions=-csearch_path= to the connection string or issueSELECT pg_catalog.set_config('search_path', '', false) before other SQL commands. This consideration is not specific topsql; it applies to every interface for executing arbitrary SQL commands.
Meta-Commands
Anything you enter inpsql that begins with an unquoted backslash is apsql meta-command that is processed bypsql itself. These commands makepsql more useful for administration or scripting. Meta-commands are often called slash or backslash commands.
The format of apsql command is the backslash, followed immediately by a command verb, then any arguments. The arguments are separated from the command verb and each other by any number of whitespace characters.
To include whitespace in an argument you can quote it with single quotes. To include a single quote in an argument, write two single quotes within single-quoted text. Anything contained in single quotes is furthermore subject to C-like substitutions for\n (new line),\t (tab),\b (backspace),\r (carriage return),\f (form feed),\digits (octal), and\xdigits (hexadecimal). A backslash preceding any other character within single-quoted text quotes that single character, whatever it is.
Within an argument, text that is enclosed in backquotes (`) is taken as a command line that is passed to the shell. The output of the command (with any trailing newline removed) replaces the backquoted text.
If an unquoted colon (:) followed by apsql variable name appears within an argument, it is replaced by the variable's value, as described inSQL Interpolation.
Some commands take anSQL identifier (such as a table name) as argument. These arguments follow the syntax rules ofSQL: Unquoted letters are forced to lowercase, while double quotes ( Parsing for arguments stops at the end of the line, or when another unquoted backslash is found. An unquoted backslash is taken as the beginning of a new meta-command. The special sequence The following meta-commands are defined: 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 Establishes a new connection to aPostgreSQL 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 Specifying any of 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 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 ifpsql 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: Sets the title of any tables being printed as the result of a query or unset any such title. This command is equivalent to Changes the current working directory to To print your current working directory, use Outputs information about the current database connection. Performs a frontend (client) copy. This is an operation that runs anSQLCOPY 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 For The syntax of this command is similar to that of theSQLCOPY command. All options other than the data source/destination are as specified forCOPY. Because of this, special parsing rules apply to the Another way to obtain the same result as These operations are not as efficient as theSQL Shows the copyright and distribution terms ofPostgreSQL. Executes the current query buffer (like 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, The vertical header, displayed as the leftmost column, contains the values found in column The horizontal header, displayed as the first row, contains the values found in column Inside the crosstab grid, for each distinct value For each relation (table, view, materialized view, index, sequence, or foreign table) or composite type matching the For some types of relation, The command form By default, only user-created objects are shown; supply a pattern or the If Lists aggregate functions, together with their return type and the data types they operate on. If Lists access methods. If Lists tablespaces. If Lists conversions between character-set encodings. If Lists type casts. If Shows the descriptions of objects of type Descriptions for objects can be created with theCOMMENTSQL command. 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 TheALTER DEFAULT PRIVILEGES command is used to set default access privileges. The meaning of the privilege display is explained underGRANT. Lists domains. If In this group of commands, the letters Lists foreign servers (mnemonic:“external servers”). If Lists foreign tables (mnemonic:“external tables”). If Lists user mappings (mnemonic:“external users”). If Lists foreign-data wrappers (mnemonic:“external wrappers”). If 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 To look up functions taking arguments or returning values of a specific data type, use your pager's search capability to scroll through the Lists text search configurations. If Lists text search dictionaries. If Lists text search parsers. If Lists text search templates. If Lists database roles. (Since the concepts of“users” and“groups” have been unified into“roles”, this command is now equivalent to This is an alias for Lists procedural languages. If Lists schemas (namespaces). If Lists operators with their operand and result types. If Lists collations. If Lists tables, views and sequences with their associated access privileges. If TheGRANT andREVOKE commands are used to set access privileges. The meaning of the privilege display is explained underGRANT. Lists defined configuration settings. These settings can be role-specific, database-specific, or both. TheALTER ROLE andALTER DATABASE commands are used to define per-role and per-database configuration settings. Lists data types. If Lists database roles. (Since the concepts of“users” and“groups” have been unified into“roles”, this command is now equivalent to Lists installed extensions. If Lists event triggers. If If The new query buffer is then re-parsed according to the normal rules ofpsql, where the whole buffer is treated as a single line. (Thus you cannot make scripts this way. Use 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. See underEnvironment for how to configure and customize your editor. 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: If the first argument is an unquoted If you use the This command fetches and edits the definition of the named function, in the form of a The target function can be specified by name alone, or by name and arguments, for example If no function is specified, a blank 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.) See underEnvironment for how to configure and customize your editor. Sets the client character set encoding. Without an argument, this command shows the current encoding. Repeats the most recent server error message at maximum verbosity, as though This command fetches and edits the definition of the named view, in the form of a If no view is specified, a blank If a line number is specified,psql will position the cursor on the specified line of the view definition. Sets the field separator for unaligned query output. The default is the vertical bar ( Sends the current query input buffer to the server, and optionally stores the query's output in A bare 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 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 bepsql meta-commands nor containpsql variable references. If any individual query fails, execution of the remaining queries continues unless Sends the current query input buffer to the server and stores the query's output intopsql variables (seeVariables). 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: If you specify a 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. Gives syntax help on the specifiedSQL command. If To simplify typing, commands that consists of several words do not have to be quoted. Thus it is fine to type Turns onHTML query output format. If theHTML format is already on, it is switched back to the default aligned text format. This command is for compatibility and convenience, but see Reads input from the file If If you want to see the lines on the screen as they are read you must set the variable The List the databases in the server and show their names, owners, character set encodings, and access privileges. If Reads the large object withOID Use Stores the file into aPostgreSQL large object. Optionally, it associates the given comment with the object. Example: 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 Note that this command is subtly different from the server-side Shows a list of allPostgreSQL large objects currently stored in the database, along with any comments provided for them. Deletes the large object withOID Use Arranges to save future query results to the file “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 To intersperse text output in between query results, use Print the current query buffer to the standard output. 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 Prompts the user to supply text, which is assigned to the variable By default, This command sets options affecting the output of query result tables. Adjustable printing options are: The Sets the target width for the If 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 Sets the field separator to use in unaligned output format to a zero byte. If Sets the output format to one of The Sets the border line drawing style to one of Illustrations of how these different formats look can be seen in theExamples section. There are various shortcut commands for Quits thepsql program. In a script file, only execution of that script is terminated. This command is identical to Resets (clears) the query buffer. Printpsql's command line history to Sets thepsql variable Valid variable names can contain letters, digits, and underscores. See the sectionVariables 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. This command is unrelated to theSQL commandSET. Sets the environment variable This command fetches and shows the definition of the named function, in the form of a The target function can be specified by name alone, or by name and arguments, for example If This command fetches and shows the definition of the named view, in the form of a If Toggles the display of output column name headings and row count footer. This command is equivalent to Specifies attributes to be placed within the Without parameter, toggles a display of how long each SQL statement takes, in milliseconds. With parameter, sets same. Unsets (deletes) thepsql variable Outputs the current query buffer to the file Repeatedly execute the current query buffer (as Sets or toggles expanded table formatting mode. As such it is equivalent to Lists tables, views and sequences with their associated access privileges. If a This is an alias for Escapes to a separate shell or executes the shell command Shows help information. The optional The various Whenever the Within a pattern, A pattern that contains a dot ( Advanced users can use regular-expression notations such as character classes, for example") protect letters from case conversion and allow incorporation of whitespace into the identifier. Within double quotes, paired double quotes reduce to a single double quote in the resulting name. For example,FOO"BAR"BAZ is interpreted asfooBARbaz, and"A weird"" name" becomesA weird" name.\\ (two backslashes) marks the end of arguments and continues parsingSQL commands, if any. That waySQL andpsql 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.\a\pset for a more general solution.\c or\connect [ -reuse-previous=on|off ] [dbname [username ] [host ] [port ] |conninfo ]conninfo connection string as detailed inSection 32.1.1. If no arguments are given, a new connection is made using the same parameters as before.dbname,username,host orport as- is equivalent to omitting that parameter.sslmode. By default, parameters are re-used in the positional syntax, but not when aconninfo 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 theconninfo string is taken from the existing connection's parameters. An exception is that if thehost setting is changed from its previous value using the positional syntax, anyhostaddr 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, thelibpq default is used.=> \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 ]\pset title. (The name of this command derives from“caption”, as it was previously only used to set the caption in anHTML table.)title\cd [directory ]directory. Without argument, changes to the current user's home directory.Tip
\! pwd.\conninfo\copy {table [ (column_list ) ] | (query ) } {from |to } {'filename' | program'command' | stdin | stdout | pstdin | pstdout } [ [ with ] (option [, ...] ) ]program is specified,command is executed bypsql and the data passed from or tocommand 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.\copy ... from stdin, data rows are read from the same source that issued the command, continuing until\. is read or the stream reachesEOF. 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 aspsql command output, and theCOPY command status is not printed (since it might be confused with a data row). To read/writepsql's standard input or output regardless of the current command source orcount\o option, writefrom pstdin orto pstdout.\copy command. In particular,psql's variable substitution rules and backslash escapes do not apply.Tip
\copy ... to is to use theSQLCOPY ... TO STDOUT command and terminate it with\g orfilename\g |. Unlikeprogram\copy, this method allows the command to span multiple lines; also, variable interpolation and backquote expansion can be used.Tip
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 theSQL command might be preferable.\copyright\crosstabview [colV [colH [colD [sortcolH ] ] ] ]\g) and shows the results in a crosstab grid. The query must return at least three columns. The output column identified bycolV becomes a vertical header and the output column identified bycolH becomes a horizontal header.colD identifies the output column to display within the grid.sortcolH identifies an optional sort column for the horizontal header.colV is taken as column 1 andcolH as column 2.colH must differ fromcolV. IfcolD is not specified, then there must be exactly three columns in the query result, and the column that is neithercolV norcolH is taken to becolD.colV, in the same order as in the query results, but with duplicates removed.colH, with duplicates removed. By default, these appear in the same order as in the query results. But if the optionalsortcolH argument is given, it identifies a column whose values must be integer numbers, and the values fromcolH will appear in the horizontal header sorted according to the correspondingsortcolH values.x ofcolH and each distinct valuey ofcolV, the cell located at the intersection(x,y) contains the value of thecolD column in the query result row for which the value ofcolH isx and the value ofcolV isy. If there is no such row, the cell is empty. If there are multiple such rows, an error is reported.\d[S+] [pattern ]pattern, show all columns, their types, the tablespace (if not the default) and any special attributes such asNOT 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 inPatterns below.)\d shows additional information for each column: column values for sequences, indexed expressions for indexes, and foreign data wrapper options for foreign tables.\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-defaultreplica identity setting.S modifier to include system objects.Note
\d is used without apattern 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 ]pattern is specified, only aggregates whose names match the pattern are shown. By default, only user-created objects are shown; supply a pattern or theS modifier to include system objects.\dA[+] [pattern ]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 ]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 ]pattern is specified, only conversions whose names match the pattern are listed. By default, only user-created objects are shown; supply a pattern or theS modifier to include system objects. If+ is appended to the command name, each object is listed with its associated description.\dC[+] [pattern ]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 ]constraint,operator class,operator family,rule, andtrigger. All other comments may be viewed by the respective backslash commands for those object types.\dd displays descriptions for objects matching thepattern, 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 theS modifier to include system objects.\ddp [pattern ]pattern is specified, only entries whose role name or schema name matches the pattern are listed.\dD[S+] [pattern ]pattern is specified, only domains whose names match the pattern are shown. By default, only user-created objects are shown; supply a pattern or theS 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 ]E,i,m,s,t, andv 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. Ifpattern is specified, only objects whose names match the pattern are listed. By default, only user-created objects are shown; supply a pattern or theS modifier to include system objects.\des[+] [pattern ]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 ]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 ]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 ]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 ]a,n,t, orw to the command. Ifpattern is specified, only functions whose names match the pattern are shown. By default, only user-created objects are shown; supply a pattern or theS 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
\df output.\dF[+] [pattern ]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 ]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 ]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 ]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 ]\du.) By default, only user-created roles are shown; supply theS modifier to include system roles. Ifpattern 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\lo_list, which shows a list of large objects.\dL[S+] [pattern ]pattern is specified, only languages whose names match the pattern are listed. By default, only user-created languages are shown; supply theS 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 ]pattern is specified, only schemas whose names match the pattern are listed. By default, only user-created objects are shown; supply a pattern or theS 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 ]pattern is specified, only operators whose names match the pattern are listed. By default, only user-created objects are shown; supply a pattern or theS 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 ]pattern is specified, only collations whose names match the pattern are listed. By default, only user-created objects are shown; supply a pattern or theS 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 ]pattern is specified, only tables, views and sequences whose names match the pattern are listed.\drds [role-pattern [database-pattern ] ]role-pattern anddatabase-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.\dT[S+] [pattern ]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 anenum type, and its associated permissions. By default, only user-created objects are shown; supply a pattern or theS modifier to include system objects.\du[S+] [pattern ]\dg.) By default, only user-created roles are shown; supply theS modifier to include system roles. Ifpattern 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 ]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 ]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]filename is specified, the file is edited; after the editor exits, its content is copied back to the query buffer. If nofilename is given, the current query buffer is copied to a temporary file which is then edited in the same fashion.\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.Tip
\echotext [ ... ]=>
\echo `date`Tue Oct 26 21:40:57 CEST 1999-n the trailing newline is not written.Tip
\o command to redirect your query output you might wish to use\qecho instead of this command.\ef [function_description [line_number]]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.foo(integer, text). The argument types must be given if there is more than one function of the same name.CREATE FUNCTION template is presented for editing.Tip
\encoding [encoding ]\errverboseVERBOSITY were set toverbose andSHOW_CONTEXT were set toalways.\ev [view_name [line_number]]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.CREATE VIEW template is presented for editing.\f [string ]|). See also\pset for a generic way of setting output options.\g [filename ]\g [ |command ]filename or pipes the output to the shell commandcommand. 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.\g is essentially equivalent to a semicolon. A\g with argument is a“one-shot” alternative to the\o command.\gexecmy_table:=>
SELECT format('create index on my_table(%I)', attname)->FROM pg_attribute->WHERE attrelid = 'my_table'::regclass AND attnum > 0->ORDER BY attnum->\gexecCREATE INDEXCREATE INDEXCREATE INDEXCREATE INDEXON_ERROR_STOP is set. Execution of each query is subject toECHO processing. (SettingECHO toall orqueries 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 ]=>
SELECT 'hello' AS var1, 10 AS var2->\gset=>\echo :var1 :var2hello 10prefix, 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_var2hello 10\h or\help[command ]command is not specified, thenpsql will list all the commands for which syntax help is available. Ifcommand is an asterisk (*), then syntax help on allSQL commands is shown.Note
\help alter table.\H or\html\pset about setting other output options.\i or\includefilenamefilename and executes it as though it had been typed on the keyboard.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
ECHO toall.\ir or\include_relativefilename\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 ]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_exportloidfilenameloid from the database and writes it tofilename. Note that this is subtly different from the server functionlo_export, which acts with the permissions of the user that the database server runs as and on the server's file system.Tip
\lo_list to find out the large object'sOID.\lo_importfilename [comment ]foo=>
\lo_import '/home/peter/pictures/photo.xcf' 'a picture of me'lo_import 152801\lo_list command.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\lo_unlinkloidloid from the database.Tip
\lo_list to find out the large object'sOID.\o or\out [filename ]\o or\out [ |command ]filename or pipe future results to the shell commandcommand. If no argument is specified, the query output is reset to the standard output.\d), but not error messages.Tip
\qecho.\p or\print\password [username ]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 ]namename. An optional prompt string,text, can be specified. (For multiword prompts, surround the text with single quotes.)\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 ] ]option indicates which option is to be set. The semantics ofvalue vary depending on the selected option. For some options, omittingvalue causes the option to be toggled or unset, as described under the particular option. If no such behavior is mentioned, then omittingvalue just results in the current setting being displayed.\pset without any arguments displays the current status of all printing options.bordervalue 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. InHTML format, this will translate directly into theborder=... 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 asborder = 2. Thelatex andlatex-longtable formats additionally allow a value of 3 to add dividing lines between data rows.columnswrapped 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 variableCOLUMNS, or the detected screen width ifCOLUMNS is not set. In addition, ifcolumns is zero then thewrapped format only affects screen output. Ifcolumns is nonzero then file and pipe output is wrapped to that width as well.expanded (orx)value is specified it must be eitheron oroff, which will enable or disable expanded mode, orauto. Ifvalue 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\pset fieldsep '\t'. The default field separator is'|' (a vertical bar).fieldsep_zerofootervalue is specified it must be eitheron oroff which will enable or disable display of the table footer (the( count). Ifn rows)value is omitted the command toggles footer display on or off.formatunaligned,aligned,wrapped,html,asciidoc,latex (usestabular),latex-longtable, ortroff-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 likealigned 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 thecolumns option. Note thatpsql will not attempt to wrap column header titles; therefore,wrapped format behaves the same asaligned if the total width needed for column headers exceeds the target.html,asciidoc,latex,latex-longtable, andtroff-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 inHTML, but inLaTeX you must have a complete document wrapper.latex-longtable also requires theLaTeXlongtable andbooktabs packages.linestyleascii,old-ascii, orunicode. Unique abbreviations are allowed. (That would mean one letter is enough.) The default setting isascii. This option only affects thealigned andwrapped output formats.ascii style uses plainASCII characters. Newlines in data are shown using a+ symbol in the right-hand margin. When thewrapped 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 plainASCII characters, using the formatting style used inPostgreSQL 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.Tip
\pset. See\a,\C,\f,\H,\t,\T, and\x.\q or\quit\qechotext [ ... ]\echo except that the output will be written to the query output channel, as set by\o.\r or\reset\s [filename ]filename. Iffilename is omitted, the history is written to the standard output (using the pager if appropriate). This command is not available ifpsql was built withoutReadline support.\set [name [value [ ... ] ] ]name tovalue, 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-setpsql variables.Note
\setenvname [value ]name tovalue, or if thevalue is not supplied, unsets the environment variable. Example:testdb=>
\setenv PAGER lesstestdb=>\setenv LESS -imx4F\sf[+]function_descriptionCREATE OR REPLACE FUNCTION command. The definition is printed to the current query output channel, as set by\o.foo(integer, text). The argument types must be given if there is more than one function of the same name.+ 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_nameCREATE OR REPLACE VIEW command. The definition is printed to the current query output channel, as set by\o.+ is appended to the command name, then the output lines are numbered from 1.\t\pset tuples_only and is provided for convenience.\Ttable_optionstable tag inHTML output format. This command is equivalent to\pset tableattr.table_options\timing [on |off ]\unsetnamename.\w or\writefilename\w or\write|commandfilename or pipes it to the shell commandcommand.\watch [seconds ]\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 ]\pset expanded.\z [pattern ]pattern is specified, only tables, views and sequences whose names match the pattern are listed.\dp (“display privileges”).\! [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 ]topic parameter (defaulting tocommands) selects which part ofpsql is explained:commands describespsql's backslash commands;options describes the command-line options that can be passed topsql; andvariables shows help aboutpsql configuration variables.Patterns
\d commands accept apattern 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 namedfoo. 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 namedFOO"BAR (notfoo"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 namedfooFOObar.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 bevisible 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.* 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 withint. But within double quotes,* and? lose these special meanings and are just matched literally..) is interpreted as a schema name pattern followed by an object name pattern. For example,\dt foo*.*bar* displays all tables whose table name includesbar that are in schemas whose schema name starts withfoo. 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.[0-9] to match any digit. All regular expression special characters work as specified inSection 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.,( forR+|)R*( forR|)R?$ is not needed as a regular-expression character since the pattern must match the whole name, unlike the usual interpretation of regular expressions (in other words,$ is automatically appended to your pattern). Write* at the beginning and/or end if you don't wish the pattern to be anchored. Note that within double quotes, all regular expression special characters lose their special meanings and are matched literally. Also, the regular expression special characters are matched literally in operator name patterns (i.e., the argument of\do).
Advanced Features
Variables
psql provides variable substitution features similar to common Unix command shells. Variables are simply name/value pairs, where the value can be any string of any length. The name must consist of letters (including non-Latin letters), digits, and underscores.
To set a variable, use thepsql meta-command\set. For example,
testdb=>\set foo bar sets the variablefoo to the valuebar. To retrieve the content of the variable, precede the name with a colon, for example:
testdb=>\echo :foobarThis works in both regular SQL commands and meta-commands; there is more detail inSQL Interpolation, below.
If you call\set without a second argument, the variable is set, with an empty string as value. To unset (i.e., delete) a variable, use the command\unset. To show the values of all variables, call\set without any argument.
Note
The arguments of\set are subject to the same substitution rules as with other commands. Thus you can construct interesting references such as\set :foo 'something' and get“soft links” or“variable variables” ofPerl orPHP fame, respectively. Unfortunately (or fortunately?), there is no way to do anything useful with these constructs. On the other hand,\set bar :foo is a perfectly valid way to copy a variable.
A number of these variables are treated specially bypsql. 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 ofpsql. 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.
AUTOCOMMITWhen
on(the default), each SQL command is automatically committed upon successful completion. To postpone commit in this mode, you must enter aBEGINorSTART TRANSACTIONSQL command. Whenoffor unset, SQL commands are not committed until you explicitly issueCOMMITorEND. The autocommit-off mode works by issuing an implicitBEGINfor you, just before any command that is not already in a transaction block and is not itself aBEGINor other transaction-control command, nor a command that cannot be executed inside a transaction block (such asVACUUM).Note
In autocommit-off mode, you must explicitly abandon any failed transaction by entering
ABORTorROLLBACK. Also keep in mind that if you exit the session without committing, your work will be lost.Note
The autocommit-on mode isPostgreSQL'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
psqlrcfile or your~/.psqlrcfile.COMP_KEYWORD_CASEDetermines which letter case to use when completing an SQL key word. If set to
lowerorupper, the completed word will be in lower or upper case, respectively. If set topreserve-lowerorpreserve-upper(the default), the completed word will be in the case of the word already entered, but words being completed without anything entered will be in lower or upper case, respectively.DBNAMEThe 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.
ECHOIf set to
all, all nonempty input lines are printed to standard output as they are read. (This does not apply to lines read interactively.) To select this behavior on program start-up, use the switch-a. If set toqueries,psql prints each query to standard output as it is sent to the server. The switch for this is-e. If set toerrors, then only failed queries are displayed on standard error output. The switch for this is-b. If unset, or if set tonone(or any other value than those above) then no queries are displayed.ECHO_HIDDENWhen this variable is set to
onand a backslash command queries the database, the query is first shown. This feature helps you to studyPostgreSQL internals and provide similar functionality in your own programs. (To select this behavior on program start-up, use the switch-E.) If you set the variable to the valuenoexec, the queries are just shown but are not actually sent to the server and executed.ENCODINGThe current client character set encoding.
FETCH_COUNTIf this variable is set to an integer value > 0, the results of
SELECTqueries are fetched and displayed in groups of that many rows, rather than the default behavior of collecting the entire result set before display. Therefore only a limited amount of memory is used, regardless of the size of the result set. Settings of 100 to 1000 are commonly used when enabling this feature. Keep in mind that when using this feature, a query might fail after having already displayed some rows.Tip
Although you can use any output format with this feature, the default
alignedformat tends to look bad because each group ofFETCH_COUNTrows will be formatted separately, leading to varying column widths across the row groups. The other output formats work better.HISTCONTROLIf this variable is set to
ignorespace, lines which begin with a space are not entered into the history list. If set to a value ofignoredups, lines matching the previous history line are not entered. A value ofignorebothcombines the two options. If unset, or if set tonone(or any other value than those above), all lines read in interactive mode are saved on the history list.Note
This feature was shamelessly plagiarized fromBash.
HISTFILEThe file name that will be used to store the history list. The default value is
~/.psql_history. For example, putting:\set HISTFILE ~/.psql_history- :DBNAME
in
~/.psqlrcwill causepsql to maintain a separate history for each database.Note
This feature was shamelessly plagiarized fromBash.
HISTSIZEThe number of commands to store in the command history. The default value is 500.
Note
This feature was shamelessly plagiarized fromBash.
HOSTThe 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.
IGNOREEOFIf unset, sending anEOF character (usuallyControl+D) to an interactive session ofpsql will terminate the application. If set to a numeric value, that manyEOF characters are ignored before the application terminates. If the variable is set but has no numeric value, the default is 10.
Note
This feature was shamelessly plagiarized fromBash.
LASTOIDThe value of the last affected OID, as returned from an
INSERTor\lo_importcommand. This variable is only guaranteed to be valid until after the result of the nextSQL command has been displayed.ON_ERROR_ROLLBACKWhen set to
on, if a statement in a transaction block generates an error, the error is ignored and the transaction continues. When set tointeractive, such errors are only ignored in interactive sessions, and not when reading script files. When unset or set tooff, a statement in a transaction block that generates an error aborts the entire transaction. The error rollback mode works by issuing an implicitSAVEPOINTfor you, just before each command that is in a transaction block, and then rolling back to the savepoint if the command fails.ON_ERROR_STOPBy default, command processing continues after an error. When this variable is set to
on, processing will instead stop immediately. In interactive mode,psql will return to the command prompt; otherwise,psql will exit, returning error code 3 to distinguish this case from fatal error conditions, which are reported using error code 1. In either case, any currently running scripts (the top-level script, if any, and any other scripts which it may have in invoked) will be terminated immediately. If the top-level command string contained multiple SQL commands, processing will stop with the current command.PORTThe 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.
PROMPT1PROMPT2PROMPT3These specify what the promptspsql issues should look like. SeePrompting below.
QUIETSetting this variable to
onis equivalent to the command line option-q. It is probably not too useful in interactive mode.SHOW_CONTEXTThis variable can be set to the values
never,errors, oralwaysto control whetherCONTEXTfields are displayed in messages from the server. The default iserrors(meaning that context will be shown in error messages, but not in notice or warning messages). This setting has no effect whenVERBOSITYis set toterse. (See also\errverbose, for use when you want a verbose version of the error you just got.)SINGLELINESetting this variable to
onis equivalent to the command line option-S.SINGLESTEPSetting this variable to
onis equivalent to the command line option-s.USERThe 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.
VERBOSITYThis variable can be set to the values
default,verbose, orterseto control the verbosity of error reports. (See also\errverbose, for use when you want a verbose version of the error you just got.)
SQL Interpolation
A key feature ofpsql variables is that you can substitute (“interpolate”) them into regularSQL 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 ( would query the table 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: Variable interpolation will not be performed within quotedSQL literals and identifiers. Therefore, a construction such as 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: (Note that this still won't work if Since colons can legally appear in SQL commands, an apparent attempt at interpolation (that is, The colon syntax for variables is standardSQL for embedded query languages, such asECPG. The colon syntaxes for array slices and type casts arePostgreSQL 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 apsql extension.:). For example,testdb=>
\set foo 'my_table'testdb=>SELECT * FROM :foo;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.testdb=>
\set foo 'my_table'testdb=>SELECT * FROM :"foo";':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).testdb=>
\set content `cat my_file.txt`testdb=>INSERT INTO my_table VALUES (:'content');my_file.txt contains NUL bytes.psql does not support embedded NUL bytes in variable values.):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.
Prompting
The promptspsql issues can be customized to your preference. The three variables The value of the selected prompt variable is printed literally, except where a percent sign ( The full host name (with domain name) of the database server, or The host name of the database server, truncated at the first dot, or The port number at which the database server is listening. The database session user name. (The expansion of this value might change during a database session as the result of the command The name of the current database. Like If the session user is a database superuser, then a The process ID of the backend currently connected to. In prompt 1 normally Transaction status: an empty string when not in a transaction block, or The line number inside the current statement, starting from The character with the indicated octal code is substituted. The value of thepsql variable The output of 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 ofReadline to work properly, these non-printing control characters must be designated as invisible by surrounding them with results in a boldfaced ( To insert a percent sign into your prompt, write This feature was shamelessly plagiarized fromtcsh.PROMPT1,PROMPT2, andPROMPT3 contain strings and special escape sequences that describe the appearance of the prompt. Prompt 1 is the normal prompt that is issued whenpsql 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 anSQLCOPY FROM STDIN command and you need to type in a row value on the terminal.%) is encountered. Depending on the next character, certain other text is substituted instead. Defined substitutions are:%M[local] if the connection is over a Unix domain socket, or[local:, if the Unix domain socket is not at the compiled in default location./dir/name]%m[local] if the connection is over a Unix domain socket.%>%nSET SESSION AUTHORIZATION.)%/%~%/, but the output is~ (tilde) if the database is your default database.%##, otherwise a>. (The expansion of this value might change during a database session as the result of the commandSET SESSION AUTHORIZATION.)%p%R=, but^ if in single-line mode, or! if the session is disconnected from the database (which can happen if\connect fails). In prompt 2%R is replaced by a character that depends on whypsql expects more input:- if the command simply wasn't terminated yet, but* if there is an unfinished/* ... */ comment, a single quote if there is an unfinished quoted string, a double quote if there is an unfinished quoted identifier, a dollar sign if there is an unfinished dollar-quoted string, or( if there is an unmatched left parenthesis. In prompt 3%R doesn't produce anything.%x* when in a transaction block, or! when in a failed transaction block, or? when the transaction state is indeterminate (for example, because there is no connection).%l1.%digits%:name:name. See the sectionVariables for details.%`command`command, similar to ordinary“back-tick” substitution.%[ ...%]%[ and%]. Multiple pairs of these can occur within the prompt. For example:testdb=> \set PROMPT1 '%[%033[1;33;40m%]%n@%/%R%[%033[0m%]%# '
1;) yellow-on-black (33;40) prompt on VT100-compatible, color-capable terminals.%%. The default prompts are'%/%R%# ' for prompts 1 and 2, and'>> ' for prompt 3.Note
Command-Line Editing
psql supports theReadline library for convenient line editing and retrieval. The command history is automatically saved whenpsql exits and is reloaded whenpsql starts up. Tab-completion is also supported, although the completion logic makes no claim to be anSQL parser. The queries generated by tab-completion can also interfere with other SQL commands, e.g., (This is not apsql but aReadline feature. Read its documentation for further details.)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:$if psqlset disable-completion on$endif
Environment
COLUMNSIf
\pset columnsis zero, controls the width for thewrappedformat and width for determining if wide output requires the pager or should be switched to the vertical format in expanded auto mode.PAGERIf the query results do not fit on the screen, they are piped through this command. Typical values are
moreorless. The default is platform-dependent. Use of the pager can be disabled by settingPAGERto empty, or by using pager-related options of the\psetcommand.PGDATABASEPGHOSTPGPORTPGUSERDefault connection parameters (seeSection 32.14).
PSQL_EDITOREDITORVISUALEditor used by the
\e,\ef, and\evcommands. These variables are examined in the order listed; the first that is set is used.The built-in default editors are
vion Unix systems andnotepad.exeon Windows systems.PSQL_EDITOR_LINENUMBER_ARGWhen
\e,\ef, or\evis used with a line number argument, this variable specifies the command-line argument used to pass the starting line number to the user's editor. For editors such asEmacs orvi, this is a plus sign. Include a trailing space in the value of the variable if there needs to be space between the option name and the line number. Examples:PSQL_EDITOR_LINENUMBER_ARG='+'PSQL_EDITOR_LINENUMBER_ARG='--line '
The default is
+on Unix systems (corresponding to the default editorvi, and useful for many other common editors); but there is no default on Windows systems.PSQL_HISTORYAlternative location for the command history file. Tilde (
~) expansion is performed.PSQLRCAlternative location of the user's
.psqlrcfile. Tilde (~) expansion is performed.SHELLCommand executed by the
\!command.TMPDIRDirectory for storing temporary files. The default is
/tmp.
This utility, like most otherPostgreSQL utilities, also uses the environment variables supported bylibpq (seeSection 32.14).
Files
psqlrcand~/.psqlrcUnless it is passed an
-Xoption,psql attempts to read and execute commands from the system-wide startup file (psqlrc) and then the user's personal startup file (~/.psqlrc), after connecting to the database but before accepting normal commands. These files can be used to set up the client and/or the server to taste, typically with\setandSETcommands.The system-wide startup file is named
psqlrcand is sought in the installation's“system configuration” directory, which is most reliably identified by runningpg_config --sysconfdir. By default this directory will be../etc/relative to the directory containing thePostgreSQL executables. The name of this directory can be set explicitly via thePGSYSCONFDIRenvironment variable.The user's personal startup file is named
.psqlrcand is sought in the invoking user's home directory. On Windows, which lacks such a concept, the personal startup file is named%APPDATA%\postgresql\psqlrc.conf. The location of the user's startup file can be set explicitly via thePSQLRCenvironment variable.Both the system-wide startup file and the user's personal startup file can be madepsql-version-specific by appending a dash and thePostgreSQL major or minor release number to the file name, for example
~/.psqlrc-9.2or~/.psqlrc-9.2.5. The most specific version-matching file will be read in preference to a non-version-specific file..psql_historyThe command-line history is stored in the file
~/.psql_history, or%APPDATA%\postgresql\psql_historyon Windows.The location of the history file can be set explicitly via the
PSQL_HISTORYenvironment variable.
Notes
psql works best with servers of the same or an older major version. Backslash commands are particularly likely to fail if the server is of a newer version thanpsql itself. However, backslash commands of the
\dfamily should work with servers of versions back to 7.4, though not necessarily with servers newer thanpsql itself. The general functionality of running SQL commands and displaying query results should also work with servers of a newer major version, but this cannot be guaranteed in all cases.If you want to usepsql to connect to several servers of different major versions, it is recommended that you use the newest version ofpsql. Alternatively, you can keep around a copy ofpsql from each major version and be sure to use the version that matches the respective server. But in practice, this additional complication should not be necessary.
BeforePostgreSQL 9.6, the
-coption implied-X(--no-psqlrc); this is no longer the case.BeforePostgreSQL 8.4,psql allowed the first argument of a single-letter backslash command to start directly after the command, without intervening whitespace. Now, some whitespace is required.
Notes for Windows Users
psql is built as a“console application”. Since the Windows console windows use a different encoding than the rest of the system, you must take special care when using 8-bit characters withinpsql. Ifpsql detects a problematic console code page, it will warn you at startup. To change the console code page, two things are necessary:
Set the code page by entering
cmd.exe /c chcp 1252. (1252 is a code page that is appropriate for German; replace it with your value.) If you are using Cygwin, you can put this command in/etc/profile.Set the console font to
Lucida Console, because the raster font does not work with the ANSI code page.
Examples
The first example shows how to spread a command over several lines of input. Notice the changing prompt:
testdb=>CREATE TABLE my_table (testdb(>first integer not null default 0,testdb(>second text)testdb->;CREATE TABLE
Now look at the table definition again:
testdb=>\d my_table Table "my_table" Attribute | Type | Modifier-----------+---------+-------------------- first | integer | not null default 0 second | text |Now we change the prompt to something more interesting:
testdb=>\set PROMPT1 '%n@%m %~%R%# 'peter@localhost testdb=>Let's assume you have filled the table with data and want to take a look at it:
peter@localhost testdb=> SELECT * FROM my_table; first | second-------+-------- 1 | one 2 | two 3 | three 4 | four(4 rows)
You can display tables in different ways by using the\pset command:
peter@localhost testdb=>\pset border 2Border style is 2.peter@localhost testdb=>SELECT * FROM my_table;+-------+--------+| first | second |+-------+--------+| 1 | one || 2 | two || 3 | three || 4 | four |+-------+--------+(4 rows)peter@localhost testdb=>\pset border 0Border style is 0.peter@localhost testdb=>SELECT * FROM my_table;first second----- ------ 1 one 2 two 3 three 4 four(4 rows)peter@localhost testdb=>\pset border 1Border style is 1.peter@localhost testdb=>\pset format unalignedOutput format is unaligned.peter@localhost testdb=>\pset fieldsep ","Field separator is ",".peter@localhost testdb=>\pset tuples_onlyShowing only tuples.peter@localhost testdb=>SELECT second, first FROM my_table;one,1two,2three,3four,4
Alternatively, use the short commands:
peter@localhost testdb=>\a \t \xOutput format is aligned.Tuples only is off.Expanded display is on.peter@localhost testdb=>SELECT * FROM my_table;-[ RECORD 1 ]-first | 1second | one-[ RECORD 2 ]-first | 2second | two-[ RECORD 3 ]-first | 3second | three-[ RECORD 4 ]-first | 4second | four
When suitable, query results can be shown in a crosstab representation with the\crosstabview command:
testdb=>SELECT first, second, first > 2 AS gt2 FROM my_table;first | second | gt2 -------+--------+----- 1 | one | f 2 | two | f 3 | three | t 4 | four | t(4 rows)testdb=>\crosstabview first secondfirst | one | two | three | four -------+-----+-----+-------+------ 1 | f | | | 2 | | f | | 3 | | | t | 4 | | | | t(4 rows)
This second example shows a multiplication table with rows sorted in reverse numerical order and columns with an independent, ascending numerical order.
testdb=>SELECT t1.first as "A", t2.first+100 AS "B", t1.first*(t2.first+100) as "AxB",testdb(>row_number() over(order by t2.first) AS ordtestdb(>FROM my_table t1 CROSS JOIN my_table t2 ORDER BY 1 DESCtestdb(>\crosstabview "A" "B" "AxB" ordA | 101 | 102 | 103 | 104 ---+-----+-----+-----+----- 4 | 404 | 408 | 412 | 416 3 | 303 | 306 | 309 | 312 2 | 202 | 204 | 206 | 208 1 | 101 | 102 | 103 | 104(4 rows)