PostgreSQL小记-psql和sql命令帮助

PG有详细的相关帮助文档，对于psql和sql相关使用可以直接在psql中调用命令帮助，非常方便

[pg@pg data]$ psql --help

psql is the PostgreSQL interactive terminal.

Usage:

  psql [OPTION]... [DBNAME [USERNAME]]

General options:

  -c, --command=COMMAND    run only single command (SQL or internal) and exit

  -d, --dbname=DBNAME      database name to connect to (default: "pg")

  -f, --file=FILENAME      execute commands from file, then exit

  -l, --list               list available databases, then exit

  -v, --set=, --variable=NAME=VALUE

                           set psql variable NAME to VALUE

                           (e.g., -v ON_ERROR_STOP=1)

  -V, --version            output version information, then exit

  -X, --no-psqlrc          do not read startup file (~/.psqlrc)

  -1 ("one"), --single-transaction

                           execute as a single transaction (if non-interactive)

  -?, --help[=options]     show this help, then exit

      --help=commands      list backslash commands, then exit

      --help=variables     list special variables, then exit

Input and output options:

  -a, --echo-all           echo all input from script

  -b, --echo-errors        echo failed commands

  -e, --echo-queries       echo commands sent to server

  -E, --echo-hidden        display queries that internal commands generate

  -L, --log-file=FILENAME  send session log to file

  -n, --no-readline        disable enhanced command line editing (readline)

  -o, --output=FILENAME    send query results to file (or |pipe)

  -q, --quiet              run quietly (no messages, only query output)

  -s, --single-step        single-step mode (confirm each query)

  -S, --single-line        single-line mode (end of line terminates SQL command)

Output format options:

  -A, --no-align           unaligned table output mode

  -F, --field-separator=STRING

                           field separator for unaligned output (default: "|")

  -H, --html               HTML table output mode

  -P, --pset=VAR[=ARG]     set printing option VAR to ARG (see \pset command)

  -R, --record-separator=STRING

                           record separator for unaligned output (default: newline)

  -t, --tuples-only        print rows only

  -T, --table-attr=TEXT    set HTML table tag attributes (e.g., width, border)

  -x, --expanded           turn on expanded table output

  -z, --field-separator-zero

                           set field separator for unaligned output to zero byte

  -0, --record-separator-zero

                           set record separator for unaligned output to zero byte

Connection options:

  -h, --host=HOSTNAME      database server host or socket directory (default: "local socket")

  -p, --port=PORT          database server port (default: "5432")

  -U, --username=USERNAME  database user name (default: "pg")

  -w, --no-password        never prompt for password

  -W, --password           force password prompt (should happen automatically)

For more information, type "\?" (for internal commands) or "\help" (for SQL

commands) from within psql, or consult the psql section in the PostgreSQL

documentation.

Report bugs to <

[email protected]

>.

[pg@pg data]$

postgres=# \?

General

  \copyright             show PostgreSQL usage and distribution terms

  \crosstabview [COLUMNS] execute query and display results in crosstab

  \errverbose            show most recent error message at maximum verbosity

  \g [FILE] or ;         execute query (and send results to file or |pipe)

  \gexec                 execute query, then execute each value in its result

  \gset [PREFIX]         execute query and store results in psql variables

  \gx [FILE]             as \g, but forces expanded output mode

  \q                     quit psql

  \watch [SEC]           execute query every SEC seconds

Help

  \? [commands]          show help on backslash commands

  \? options             show help on psql command-line options

  \? variables           show help on special variables

  \h [NAME]              help on syntax of SQL commands, * for all commands

Query Buffer

  \e [FILE] [LINE]       edit the query buffer (or file) with external editor

  \ef [FUNCNAME [LINE]]  edit function definition with external editor

  \ev [VIEWNAME [LINE]]  edit view definition with external editor

  \p                     show the contents of the query buffer

  \r                     reset (clear) the query buffer

  \s [FILE]              display history or save it to file

  \w FILE                write query buffer to file

Input/Output

  \copy ...              perform SQL COPY with data stream to the client host

  \echo [STRING]         write string to standard output

  \i FILE                execute commands from file

  \ir FILE               as \i, but relative to location of current script

  \o [FILE]              send all query results to file or |pipe

  \qecho [STRING]        write string to query output stream (see \o)

Conditional

  \if EXPR               begin conditional block

  \elif EXPR             alternative within current conditional block

  \else                  final alternative within current conditional block

  \endif                 end conditional block

Informational

  (options: S = show system objects, + = additional detail)

  \d[S+]                 list tables, views, and sequences

  \d[S+]  NAME           describe table, view, sequence, or index

  \da[S]  [PATTERN]      list aggregates

  \dA[+]  [PATTERN]      list access methods

  \db[+]  [PATTERN]      list tablespaces

  \dc[S+] [PATTERN]      list conversions

  \dC[+]  [PATTERN]      list casts

  \dd[S]  [PATTERN]      show object descriptions not displayed elsewhere

  \dD[S+] [PATTERN]      list domains

  \ddp    [PATTERN]      list default privileges

  \dE[S+] [PATTERN]      list foreign tables

  \det[+] [PATTERN]      list foreign tables

  \des[+] [PATTERN]      list foreign servers

  \deu[+] [PATTERN]      list user mappings

  \dew[+] [PATTERN]      list foreign-data wrappers

  \df[antw][S+] [PATRN]  list [only agg/normal/trigger/window] functions

  \dF[+]  [PATTERN]      list text search configurations

  \dFd[+] [PATTERN]      list text search dictionaries

  \dFp[+] [PATTERN]      list text search parsers

  \dFt[+] [PATTERN]      list text search templates

  \dg[S+] [PATTERN]      list roles

  \di[S+] [PATTERN]      list indexes

  \dl                    list large objects, same as \lo_list

  \dL[S+] [PATTERN]      list procedural languages

  \dm[S+] [PATTERN]      list materialized views

  \dn[S+] [PATTERN]      list schemas

  \do[S]  [PATTERN]      list operators

  \dO[S+] [PATTERN]      list collations

  \dp     [PATTERN]      list table, view, and sequence access privileges

  \drds [PATRN1 [PATRN2]] list per-database role settings

  \dRp[+] [PATTERN]      list replication publications

  \dRs[+] [PATTERN]      list replication subscriptions

  \ds[S+] [PATTERN]      list sequences

  \dt[S+] [PATTERN]      list tables

  \dT[S+] [PATTERN]      list data types

  \du[S+] [PATTERN]      list roles

  \dv[S+] [PATTERN]      list views

  \dx[+]  [PATTERN]      list extensions

  \dy     [PATTERN]      list event triggers

  \l[+]   [PATTERN]      list databases

  \sf[+]  FUNCNAME       show a function's definition

  \sv[+]  VIEWNAME       show a view's definition

  \z      [PATTERN]      same as \dp

Formatting

  \a                     toggle between unaligned and aligned output mode

  \C [STRING]            set table title, or unset if none

  \f [STRING]            show or set field separator for unaligned query output

  \H                     toggle HTML output mode (currently off)

  \pset [NAME [VALUE]]   set table output option

                         (NAME := {border|columns|expanded|fieldsep|fieldsep_zero|

                         footer|format|linestyle|null|numericlocale|pager|

                         pager_min_lines|recordsep|recordsep_zero|tableattr|title|

                         tuples_only|unicode_border_linestyle|

                         unicode_column_linestyle|unicode_header_linestyle})

  \t [on|off]            show only rows (currently off)

  \T [STRING]            set HTML <table> tag attributes, or unset if none

  \x [on|off|auto]       toggle expanded output (currently off)

Connection

  \c[onnect] {[DBNAME|- USER|- HOST|- PORT|-] | conninfo}

                         connect to new database (currently "postgres")

  \conninfo              display information about current connection

  \encoding [ENCODING]   show or set client encoding

  \password [USERNAME]   securely change the password for a user

Operating System

  \cd [DIR]              change the current working directory

  \setenv NAME [VALUE]   set or unset environment variable

  \timing [on|off]       toggle timing of commands (currently off)

  \! [COMMAND]           execute command in shell or start interactive shell

Variables

  \prompt [TEXT] NAME    prompt user to set internal variable

  \set [NAME [VALUE]]    set internal variable, or list all if no parameters

  \unset NAME            unset (delete) internal variable

Large Objects

  \lo_export LOBOID FILE

  \lo_import FILE [COMMENT]

  \lo_list

  \lo_unlink LOBOID      large object operations

postgres=#

以上的帮助信息非常方便有效，对于以下的事例，直接查看帮助信息就可以理解

1)

$ psql -h 192.168.6.12 -p 5432 -d  postgres -U pg -t -c "select * from test"

Password for user pg:

  1

  2

$ psql -h 192.168.6.12 -p 5432 -d  postgres -U pg  -L session

$ ls

logfile  record  session

2)

postgres=# \h alter user

Command:     ALTER USER

Description: change a database role

Syntax:

ALTER USER role_specification [ WITH ] option [ ... ]

where option can be:

      SUPERUSER | NOSUPERUSER

    | CREATEDB | NOCREATEDB

    | CREATEROLE | NOCREATEROLE

    | INHERIT | NOINHERIT

    | LOGIN | NOLOGIN

    | REPLICATION | NOREPLICATION

    | BYPASSRLS | NOBYPASSRLS

    | CONNECTION LIMIT connlimit

    | [ ENCRYPTED ] PASSWORD 'password'

    | VALID UNTIL 'timestamp'

ALTER USER name RENAME TO new_name

ALTER USER { role_specification | ALL } [ IN DATABASE database_name ] SET configuration_parameter { TO | = } { value | DEFAULT }

ALTER USER { role_specification | ALL } [ IN DATABASE database_name ] SET configuration_parameter FROM CURRENT

ALTER USER { role_specification | ALL } [ IN DATABASE database_name ] RESET configuration_parameter

ALTER USER { role_specification | ALL } [ IN DATABASE database_name ] RESET ALL

where role_specification can be:

    role_name

  | CURRENT_USER

  | SESSION_USER

postgres=# alter user pg with password 'pg'

postgres=# \o record

postgres=# select * from test;

postgres=# insert into test values (10);

postgres=# \! ls

postgres=# \! vi record