openGauss gsql 常用元命令 二
\df 查看当前数据库函数信息
openGauss=# \df
********* QUERY **********
SELECT n.nspname as "Schema",
p.proname as "Name",
pg_catalog.pg_get_function_result(p.oid) as "Result data type",
pg_catalog.pg_get_function_arguments(p.oid) as "Argument data types",
CASE
WHEN p.proisagg THEN 'agg'
WHEN p.proiswindow THEN 'window'
WHEN p.prorettype = 'pg_catalog.trigger'::pg_catalog.regtype THEN 'trigger'
ELSE 'normal'
END as "Type" ,
fencedmode as "fencedmode"
,
propackage as "propackage"
,
prokind as "prokind"
FROM pg_catalog.pg_proc p
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
WHERE pg_catalog.pg_function_is_visible(p.oid)
AND n.nspname <> 'pg_catalog'
AND n.nspname <> 'db4ai'
AND n.nspname <> 'information_schema'
ORDER BY 1, 2, 4;
**************************
List of functions
Schema | Name | Result data type | Argument data types | Type | fencedmode | propackage | prokind
--------+-----------+------------------+--------------------------------------------------+--------+------------+------------+---------
public | fuc_worth | numeric | price numeric, amount integer, OUT worth numeric | normal | f | f | f
(1 row)
\dx 查看已安装的扩展程序信息
openGauss=# \dx
********* QUERY **********
SELECT e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description"
FROM pg_catalog.pg_extension e LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'::pg_catalog.regclass
ORDER BY 1;
**************************
List of installed extensions
Name | Version | Schema | Description
-----------------+---------+------------+--------------------------------------------------
dist_fdw | 1.0 | pg_catalog | foreign-data wrapper for distfs access
file_fdw | 1.0 | pg_catalog | foreign-data wrapper for flat file access
hdfs_fdw | 1.0 | pg_catalog | foreign-data wrapper for flat file access
hstore | 1.1 | pg_catalog | data type for storing sets of (key, value) pairs
log_fdw | 1.0 | pg_catalog | Foreign Data Wrapper for accessing logging data
mot_fdw | 1.0 | pg_catalog | foreign-data wrapper for MOT access
plpgsql | 1.0 | pg_catalog | PL/pgSQL procedural language
security_plugin | 1.0 | pg_catalog | provides security functionality
(8 rows)
\x 语法 \x[on|off|auto] 设置语句的输出模式，模式为行的方式输出，执行 \x on 切换为以列的方式来显示
openGauss=# \x
Expanded display is on.
openGauss=# \dx
********* QUERY **********
SELECT e.extname AS "Name", e.extversion AS "Version", n.nspname AS "Schema", c.description AS "Description"
FROM pg_catalog.pg_extension e LEFT JOIN pg_catalog.pg_namespace n ON n.oid = e.extnamespace LEFT JOIN pg_catalog.pg_description c ON c.objoid = e.oid AND c.classoid = 'pg_catalog.pg_extension'::pg_catalog.regclass
ORDER BY 1;
**************************
List of installed extensions
-[ RECORD 1 ]-------------------------------------------------
Name | dist_fdw
Version | 1.0
Schema | pg_catalog
Description | foreign-data wrapper for distfs access
-[ RECORD 2 ]-------------------------------------------------
Name | file_fdw
Version | 1.0
Schema | pg_catalog
Description | foreign-data wrapper for flat file access
-[ RECORD 3 ]-------------------------------------------------
\timing 语法 \timing [on|off] 控制显示 SQL 的执行时间，默认为 off, on 为显示 SQL 语句的执行时间
openGauss=# select * from test;
id
----
1
(1 row)
openGauss=# \timing on
Timing is on.
openGauss=# select * from test;
id
----
1
(1 row)
Time: 0.352 ms
\h 用于获取 SQL 语句的帮助，例如 \h merge
openGauss=# \h merge
Command: MERGE
Description: insert, update, or delete rows of a table based upon source data
Syntax:
MERGE [/*+ plan_hint */] INTO table_name [ [ AS ] alias ]
USING { { table_name | view_name } | subquery } [ [ AS ] alias ]
ON ( condition )
[
WHEN MATCHED THEN
UPDATE SET { column_name = { expression | DEFAULT } |
( column_name [, ...] ) = ( { expression | DEFAULT } [, ...] ) } [, ...]
[ WHERE condition ]
]
[
WHEN NOT MATCHED THEN
INSERT { DEFAULT VALUES |
[ ( column_name [, ...] ) ] VALUES ( { expression | DEFAULT } [, ...] ) [, ...] [ WHERE condition ] }
];
? 获取 gsql 的元命令的帮助
openGauss=# \?
General
\copyright show openGauss usage and distribution terms
\g [FILE] or ; execute query (and send results to file or |pipe)
\h(\help) [NAME] help on syntax of SQL commands, * for all commands
\parallel [on [num]|off] toggle status of execute (currently off)
\q quit gsql
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
\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
\i+ FILE KEY execute commands from encrypted file
\ir FILE as \i, but relative to location of current script
\ir+ FILE KEY 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)
! os_command 用于执行操作系统命令，同 oracle 的 ！，mysql 的 system
openGauss-# \! pwd
/home/omm
openGauss-# \! ls
1.sh create_db_tables.sql test.sql
\o filename 用于重定向输出到文件，注意这个不是简单的将屏幕的内容输出到文本，而是将 SQL 语句正确执行的结果输出到文本
openGauss-# \o test.out
openGauss-# select * from test;
WARNING: Session unused timeout.
FATAL: terminating connection due to administrator command
could not send data to server: Broken pipe
The connection to the server was lost. Attempting reset: Succeeded.
openGauss=# select * from test;
openGauss=# \! cat test.out
id
----
1
(1 row)
openGauss=# select * from pg_tables;
openGauss=# \! cat test.out
id
----
1
(1 row)
schemaname | tablename | tableowner | tablespace | hasindexes | hasrules | hastriggers | tablecreator | created | last_ddl_time
--------------------+-------------------------------+------------+------------+------------+----------+-------------+--------------+-------------------------------+-------------------------------
pg_catalog | pg_statistic | omm | | t | f | f | | |
\i file.sql
\conninfo 显示 gsql 中显示会话的连接信息
\c[onnect] [DBNAME] 切换数据库
openGauss=# \conninfo
You are connected to database "postgres" as user "omm" via socket in "/opt/huawei/tmp" at port "15400".
openGauss=# \c mydb
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "mydb" as user "omm".
mydb=# \conninfo
You are connected to database "mydb" as user "omm" via socket in "/opt/huawei/tmp" at port "15400".
\echo [string] 打印字符串
mydb=# \echo Hello World!
Hello World!
\q 退出 gsql