PostgreSQL数据库自带的命令行工具--psql
文章目录
- PostgreSQL自带的命令行工具--psql
- 使用psql连接数据库
- psql帮助内容
- \copyright 发布条款
- \h SQL命令的帮助
- \? 元命令帮助
- psql元命令实际执行SQL
- 部分中文说明
- 其他说明
- 总结
- 参考
【免责声明】文章仅供学习交流，观点代表个人，与任何公司无关。
编辑|SQL和数据库技术(ID:SQLplusDB)
PostgreSQL自带的命令行工具–psql
和Oracle的sqlplus、MySQL自带命令行类似。psql是PostgreSQL自带的命令行工具，功能全面，是PostgreSQL数据库最重要的命令行工具之一。
通过psql工具可以和PostgreSQL数据库服务器进行SQL命令行交互。它是一个灵活、高效和功能强大的工具，用于管理和查询数据库。
另外，psql工具也提供了大量强大的元命令（以反斜杠“\”开头的命令）。
使用psql连接数据库
--连接数据库
shell> psql -h <主机名> -p <端口号> -U <用户名> <数据库名>
例：
ubuntu@pg-vm:~$ psql -U postgres -d postgres -h localhost
Password for user postgres:
psql (12.12 (Ubuntu 12.12-0ubuntu0.20.04.1))
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Type "help" for help.
postgres=#
psql帮助内容
通过在psql命令行键入help可以获得使用帮助的内容。
例：
postgres=# help
You are using psql, the command-line interface to PostgreSQL.
Type: \copyright for distribution terms
\h for help with SQL commands
\? for help with psql commands
\g or terminate with semicolon to execute query
\q to quit
\copyright 发布条款
postgres=# \copyright
PostgreSQL Database Management System
(formerly known as Postgres, then as Postgres95)
Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
Portions Copyright (c) 1994, The Regents of the University of California
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose, without fee, and without a written agreement
is hereby granted, provided that the above copyright notice and this
paragraph and the following two paragraphs appear in all copies.
IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATIONS TO
PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
\h SQL命令的帮助
\h获取所有的SQL命令。
postgres=# \h
Available help:
ABORT CREATE FOREIGN DATA WRAPPER DROP ROUTINE
ALTER AGGREGATE CREATE FOREIGN TABLE DROP RULE
ALTER COLLATION CREATE FUNCTION DROP SCHEMA
ALTER CONVERSION CREATE GROUP DROP SEQUENCE
ALTER DATABASE CREATE INDEX DROP SERVER
ALTER DEFAULT PRIVILEGES CREATE LANGUAGE DROP STATISTICS
ALTER DOMAIN CREATE MATERIALIZED VIEW DROP SUBSCRIPTION
ALTER EVENT TRIGGER CREATE OPERATOR DROP TABLE
ALTER EXTENSION CREATE OPERATOR CLASS DROP TABLESPACE
ALTER FOREIGN DATA WRAPPER CREATE OPERATOR FAMILY DROP TEXT SEARCH CONFIGURATION
ALTER FOREIGN TABLE CREATE POLICY DROP TEXT SEARCH DICTIONARY
ALTER FUNCTION CREATE PROCEDURE DROP TEXT SEARCH PARSER
ALTER GROUP CREATE PUBLICATION DROP TEXT SEARCH TEMPLATE
ALTER INDEX CREATE ROLE DROP TRANSFORM
ALTER LANGUAGE CREATE RULE DROP TRIGGER
ALTER LARGE OBJECT CREATE SCHEMA DROP TYPE
ALTER MATERIALIZED VIEW CREATE SEQUENCE DROP USER
ALTER OPERATOR CREATE SERVER DROP USER MAPPING
ALTER OPERATOR CLASS CREATE STATISTICS DROP VIEW
ALTER OPERATOR FAMILY CREATE SUBSCRIPTION END
ALTER POLICY CREATE TABLE EXECUTE
ALTER PROCEDURE CREATE TABLE AS EXPLAIN
ALTER PUBLICATION CREATE TABLESPACE FETCH
ALTER ROLE CREATE TEXT SEARCH CONFIGURATION GRANT
ALTER ROUTINE CREATE TEXT SEARCH DICTIONARY IMPORT FOREIGN SCHEMA
ALTER RULE CREATE TEXT SEARCH PARSER INSERT
ALTER SCHEMA CREATE TEXT SEARCH TEMPLATE LISTEN
ALTER SEQUENCE CREATE TRANSFORM LOAD
ALTER LANGUAGE CREATE RULE DROP TRIGGER
ALTER LARGE OBJECT CREATE SCHEMA DROP TYPE
ALTER MATERIALIZED VIEW CREATE SEQUENCE DROP USER
ALTER OPERATOR CREATE SERVER DROP USER MAPPING
ALTER OPERATOR CLASS CREATE STATISTICS DROP VIEW
ALTER OPERATOR FAMILY CREATE SUBSCRIPTION END
ALTER POLICY CREATE TABLE EXECUTE
ALTER PROCEDURE CREATE TABLE AS EXPLAIN
ALTER PUBLICATION CREATE TABLESPACE FETCH
ALTER ROLE CREATE TEXT SEARCH CONFIGURATION GRANT
ALTER ROUTINE CREATE TEXT SEARCH DICTIONARY IMPORT FOREIGN SCHEMA
ALTER RULE CREATE TEXT SEARCH PARSER INSERT
ALTER SCHEMA CREATE TEXT SEARCH TEMPLATE LISTEN
ALTER SEQUENCE CREATE TRANSFORM LOAD
ALTER SERVER CREATE TRIGGER LOCK
ALTER STATISTICS CREATE TYPE MOVE
ALTER SUBSCRIPTION CREATE USER NOTIFY
ALTER SYSTEM CREATE USER MAPPING PREPARE
ALTER TABLE CREATE VIEW PREPARE TRANSACTION
ALTER TABLESPACE DEALLOCATE REASSIGN OWNED
ALTER TEXT SEARCH CONFIGURATION DECLARE REFRESH MATERIALIZED VIEW
ALTER TEXT SEARCH DICTIONARY DELETE REINDEX
ALTER TEXT SEARCH PARSER DISCARD RELEASE SAVEPOINT
ALTER TEXT SEARCH TEMPLATE DO RESET
ALTER TRIGGER DROP ACCESS METHOD REVOKE
ALTER TYPE DROP AGGREGATE ROLLBACK
ALTER USER DROP CAST ROLLBACK PREPARED
ALTER USER MAPPING DROP COLLATION ROLLBACK TO SAVEPOINT
ALTER VIEW DROP CONVERSION SAVEPOINT
ALTER STATISTICS CREATE TYPE MOVE
ALTER SUBSCRIPTION CREATE USER NOTIFY
ALTER SYSTEM CREATE USER MAPPING PREPARE
ALTER TABLE CREATE VIEW PREPARE TRANSACTION
ALTER TABLESPACE DEALLOCATE REASSIGN OWNED
ALTER TEXT SEARCH CONFIGURATION DECLARE REFRESH MATERIALIZED VIEW
ALTER TEXT SEARCH DICTIONARY DELETE REINDEX
ALTER TEXT SEARCH PARSER DISCARD RELEASE SAVEPOINT
ALTER TEXT SEARCH TEMPLATE DO RESET
ALTER TRIGGER DROP ACCESS METHOD REVOKE
ALTER TYPE DROP AGGREGATE ROLLBACK
ALTER USER DROP CAST ROLLBACK PREPARED
ALTER USER MAPPING DROP COLLATION ROLLBACK TO SAVEPOINT
ALTER VIEW DROP CONVERSION SAVEPOINT
ANALYZE DROP DATABASE SECURITY LABEL
BEGIN DROP DOMAIN SELECT
CALL DROP EVENT TRIGGER SELECT INTO
CHECKPOINT DROP EXTENSION SET
CLOSE DROP FOREIGN DATA WRAPPER SET CONSTRAINTS
CLUSTER DROP FOREIGN TABLE SET ROLE
COMMENT DROP FUNCTION SET SESSION AUTHORIZATION
COMMIT DROP GROUP SET TRANSACTION
COMMIT PREPARED DROP INDEX SHOW
COPY DROP LANGUAGE START TRANSACTION
CREATE ACCESS METHOD DROP MATERIALIZED VIEW TABLE
CREATE AGGREGATE DROP OPERATOR TRUNCATE
CREATE CAST DROP OPERATOR CLASS UNLISTEN
CREATE COLLATION DROP OPERATOR FAMILY UPDATE
CREATE CONVERSION DROP OWNED VACUUM
CREATE DATABASE DROP POLICY VALUES
CREATE DOMAIN DROP PROCEDURE WITH
CREATE EVENT TRIGGER DROP PUBLICATION
CREATE EXTENSION DROP ROLE
可以通过 \n + <SQL命令>获得SQL命令的帮助。
例：
postgres=# \h create database
Command: CREATE DATABASE
Description: create a new database
Syntax:
CREATE DATABASE name
[ [ WITH ] [ OWNER [=] user_name ]
[ TEMPLATE [=] template ]
[ ENCODING [=] encoding ]
[ LC_COLLATE [=] lc_collate ]
[ LC_CTYPE [=] lc_ctype ]
[ TABLESPACE [=] tablespace_name ]
[ ALLOW_CONNECTIONS [=] allowconn ]
[ CONNECTION LIMIT [=] connlimit ]
[ IS_TEMPLATE [=] istemplate ] ]
URL: https://www.postgresql.org/docs/12/sql-createdatabase.html
? 元命令帮助
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)
\gdesc describe result of query, without executing it
\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
\? 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
\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
\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[anptw][S+] [PATRN] list [only agg/normal/procedures/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
\dP[itn+] [PATTERN] list [only index/table] partitioned relations [n=nested]
\drds [PATRN1 [PATRN2]] list per-database role settings
\dRp[+] [PATTERN] list replication publications
\dRs[+] [PATTERN] list replication subscriptions
\ds[S+] [PATTERN] list sequences
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
(border|columns|csv_fieldsep|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
例1：列出所有的数据库
postgres=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+---------+---------+-----------------------
postgres | postgres | UTF8 | C.UTF-8 | C.UTF-8 |
template0 | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
(3 rows)
例2：列出所有的 schema
postgres=# \dn
List of schemas
Name | Owner
--------+----------
public | postgres
(1 row)
例3：列出所有的数据库用户和角色
postgres=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
postgres=# \dg
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------+-----------
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS | {}
psql元命令实际执行SQL
可以通过使用“\set ECHO_HIDDEN on |off"命令来显示元命令实际执行SQL。
例：
postgres-# \set ECHO_HIDDEN on
postgres-# \l
********* QUERY **********
SELECT d.datname as "Name",
pg_catalog.pg_get_userbyid(d.datdba) as "Owner",
pg_catalog.pg_encoding_to_char(d.encoding) as "Encoding",
d.datcollate as "Collate",
d.datctype as "Ctype",
pg_catalog.array_to_string(d.datacl, E'\n') AS "Access privileges"
FROM pg_catalog.pg_database d
ORDER BY 1;
**************************
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+----------+----------+---------+---------+-----------------------
postgres | postgres | UTF8 | C.UTF-8 | C.UTF-8 |
template0 | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | C.UTF-8 | C.UTF-8 | =c/postgres +
| | | | | postgres=CTc/postgres
(3 rows)
部分中文说明
| 命令 | 说明 |
|---|---|
| \h | help \h create table |
| \d tb_name | 查看表(视图，索引，序列)结构 |
| \du | 查看用户列表 |
| \dt | 查询数据库所有表（非系统表） |
| \dS | 列出系统表和索引 |
| \di index_name | 只查看指定索引 |
| \df | 列出函数 |
| \dv | 只显示视图 |
| \ds | 只显示序列 |
| \dn | 列出所有的schema |
| \db | 显示所有的表空间 |
| \dg | 列出数据库的所有角色或用户 |
| \dp或者\z | 查看表的分配权限 |
| \c [db_name] [user_name] | 切换某用户到指定数据库 |
| \timing on/off | 显示执行sql的时间 |
| \encoding encode_type | 设置客户端编码 |
| \pset [option [value] ] | 输出格式设置 |
| \l | 显示所有数据库列表 |
| \q | 命令退出psql |
| \o filename | 文本输出执行结果 |
| \I filename | 用于执行存储在外部文件的sql语句或命令 |
| \x | 数据按列展示，类似mysql的\G |
其他说明
+：对比显示更加详细的信息，例如：\du+ \dt+ \d+
?/* ：查询匹配通配符，例如：\d tb?
pgsql -E :可以显示命令执行的对应的SQL语句
\pset边框设置
\pset boder 0 :不带任何边框
\pset boder 1 :输出内容有边框
\pset boder 2 :带边框
\pset设置文本输出格式
\pset format unaligned （默认分隔符｜）
\pset filesep ‘分隔符’ (例如：\t)
自动补全：连续单击两次tab键
执行外部命令：在psql提示符下，使用“!”命令执行外部命令。例如，“! ls”将列出当前目录中的所有文件。
总结
在本文中介绍了PostgreSQL数据库自带的命令行工具–psql的主要特点和使用方法。
参考
http://www.postgres.cn/docs/12/app-psql.html
https://www.postgresql.org/docs/14/app-psql.html