查看当前数据库版本
[postgres@192 ~]$ psql --version
psql (PostgreSQL) 14.6
[postgres@192 ~]$ psql
psql (14.6)
Type "help" for help.
[postgres@192 ~]$ pg_ctl -V
pg_ctl (PostgreSQL) 14.6
postgres=# show server_version;
server_version
----------------
14.6
(1 row)
postgres=# select version();
version
---------------------------------------------------------------------------------------------------------
PostgreSQL 14.6 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-44), 64-bit
(1 row)
postgres=# show server_version_num;
server_version_num
--------------------
140006
(1 row)
帮助信息
[postgres@192 ~]$ psql --help
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 显示发行条款
\h 显示 SQL 命令的说明
\? 显示 pgsql 命令的说明
\g 或者以分号(;)结尾以执行查询
\q 退出
postgres=# \copyright
PostgreSQL Database Management System
(formerly known as Postgres, then as Postgres95)
Portions Copyright (c) 1996-2021, 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.
postgres=# \h
Available help:
ABORT ALTER SYSTEM CREATE FOREIGN DATA WRAPPER CREATE USER MAPPING DROP ROUTINE PREPARE
ALTER AGGREGATE ALTER TABLE CREATE FOREIGN TABLE CREATE VIEW DROP RULE PREPARE TRANSACTION
ALTER COLLATION ALTER TABLESPACE CREATE FUNCTION DEALLOCATE DROP SCHEMA REASSIGN OWNED
ALTER CONVERSION ALTER TEXT SEARCH CONFIGURATION CREATE GROUP DECLARE DROP SEQUENCE REFRESH MATERIALIZED VIEW
ALTER DATABASE ALTER TEXT SEARCH DICTIONARY CREATE INDEX DELETE DROP SERVER REINDEX
ALTER DEFAULT PRIVILEGES ALTER TEXT SEARCH PARSER CREATE LANGUAGE DISCARD DROP STATISTICS RELEASE SAVEPOINT
ALTER DOMAIN ALTER TEXT SEARCH TEMPLATE CREATE MATERIALIZED VIEW DO DROP SUBSCRIPTION RESET
ALTER EVENT TRIGGER ALTER TRIGGER CREATE OPERATOR DROP ACCESS METHOD DROP TABLE REVOKE
ALTER EXTENSION ALTER TYPE CREATE OPERATOR CLASS DROP AGGREGATE DROP TABLESPACE ROLLBACK
ALTER FOREIGN DATA WRAPPER ALTER USER CREATE OPERATOR FAMILY DROP CAST DROP TEXT SEARCH CONFIGURATION ROLLBACK PREPARED
ALTER FOREIGN TABLE ALTER USER MAPPING CREATE POLICY DROP COLLATION DROP TEXT SEARCH DICTIONARY ROLLBACK TO SAVEPOINT
ALTER FUNCTION ALTER VIEW CREATE PROCEDURE DROP CONVERSION DROP TEXT SEARCH PARSER SAVEPOINT
ALTER GROUP ANALYZE CREATE PUBLICATION DROP DATABASE DROP TEXT SEARCH TEMPLATE SECURITY LABEL
ALTER INDEX BEGIN CREATE ROLE DROP DOMAIN DROP TRANSFORM SELECT
ALTER LANGUAGE CALL CREATE RULE DROP EVENT TRIGGER DROP TRIGGER SELECT INTO
ALTER LARGE OBJECT CHECKPOINT CREATE SCHEMA DROP EXTENSION DROP TYPE SET
ALTER MATERIALIZED VIEW CLOSE CREATE SEQUENCE DROP FOREIGN DATA WRAPPER DROP USER SET CONSTRAINTS
ALTER OPERATOR CLUSTER CREATE SERVER DROP FOREIGN TABLE DROP USER MAPPING SET ROLE
ALTER OPERATOR CLASS COMMENT CREATE STATISTICS DROP FUNCTION DROP VIEW SET SESSION AUTHORIZATION
ALTER OPERATOR FAMILY COMMIT CREATE SUBSCRIPTION DROP GROUP END SET TRANSACTION
ALTER POLICY COMMIT PREPARED CREATE TABLE DROP INDEX EXECUTE SHOW
ALTER PROCEDURE COPY CREATE TABLE AS DROP LANGUAGE EXPLAIN START TRANSACTION
ALTER PUBLICATION CREATE ACCESS METHOD CREATE TABLESPACE DROP MATERIALIZED VIEW FETCH TABLE
ALTER ROLE CREATE AGGREGATE CREATE TEXT SEARCH CONFIGURATION DROP OPERATOR GRANT TRUNCATE
ALTER ROUTINE CREATE CAST CREATE TEXT SEARCH DICTIONARY DROP OPERATOR CLASS IMPORT FOREIGN SCHEMA UNLISTEN
ALTER RULE CREATE COLLATION CREATE TEXT SEARCH PARSER DROP OPERATOR FAMILY INSERT UPDATE
ALTER SCHEMA CREATE CONVERSION CREATE TEXT SEARCH TEMPLATE DROP OWNED LISTEN VACUUM
ALTER SEQUENCE CREATE DATABASE CREATE TRANSFORM DROP POLICY LOAD VALUES
ALTER SERVER CREATE DOMAIN CREATE TRIGGER DROP PROCEDURE LOCK WITH
ALTER STATISTICS CREATE EVENT TRIGGER CREATE TYPE DROP PUBLICATION MOVE
ALTER SUBSCRIPTION CREATE EXTENSION CREATE USER DROP ROLE NOTIFY
显示 SQL脚本
postgres-# \h select
Command: SELECT
Description: retrieve rows from a table or view
Syntax:
[ WITH [ RECURSIVE ] with_query [, ...] ]
SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ]
[ * | expression [ [ AS ] output_name ] [, ...] ]
[ FROM from_item [, ...] ]
[ WHERE condition ]
[ GROUP BY [ ALL | DISTINCT ] grouping_element [, ...] ]
[ HAVING condition ]
[ WINDOW window_name AS ( window_definition ) [, ...] ]
[ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] select ]
[ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ]
[ LIMIT { count | ALL } ]
[ OFFSET start [ ROW | ROWS ] ]
[ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } { ONLY | WITH TIES } ]
[ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ]
where from_item can be one of:
[ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
[ TABLESAMPLE sampling_method ( argument [, ...] ) [ REPEATABLE ( seed ) ] ]
[ LATERAL ] ( select ) [ AS ] alias [ ( column_alias [, ...] ) ]
with_query_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
[ LATERAL ] function_name ( [ argument [, ...] ] )
[ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
[ LATERAL ] function_name ( [ argument [, ...] ] ) [ AS ] alias ( column_definition [, ...] )
[ LATERAL ] function_name ( [ argument [, ...] ] ) AS ( column_definition [, ...] )
[ LATERAL ] ROWS FROM( function_name ( [ argument [, ...] ] ) [ AS ( column_definition [, ...] ) ] [, ...] )
[ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ]
from_item join_type from_item { ON join_condition | USING ( join_column [, ...] ) [ AS join_using_alias ] }
from_item NATURAL join_type from_item
from_item CROSS JOIN from_item
and grouping_element can be one of:
( )
expression
( expression [, ...] )
ROLLUP ( { expression | ( expression [, ...] ) } [, ...] )
CUBE ( { expression | ( expression [, ...] ) } [, ...] )
GROUPING SETS ( grouping_element [, ...] )
and with_query is:
with_query_name [ ( column_name [, ...] ) ] AS [ [ NOT ] MATERIALIZED ] ( select | values | insert | update | delete )
[ SEARCH { BREADTH | DEPTH } FIRST BY column_name [, ...] SET search_seq_col_name ]
[ CYCLE column_name [, ...] SET cycle_mark_col_name [ TO cycle_mark_value DEFAULT cycle_mark_default ] USING cycle_path_col_name ]
TABLE [ ONLY ] table_name [ * ]
当前连接信息
-- 列出当前数据库的连接信息
postgres=# \connect
You are now connected to database "postgres" as user "postgres".
-- 列出当前数据库和连接的详细信息
postgres-# \conninfo
You are connected to database "postgres" as user "postgres" via socket in "/tmp" at port "5432".
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