openGauss每日一练第2天 | 学习心得体会

原创孙希瑞 2022-11-25

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今天的课程主要目标是学习openGauss数据库客户端工具gsql的使用。
gsql是openGass数据库提供在命令行下运行的数据库连接工具，可以通过此工具连接服务器并对其进行操作和维护，除了具备操作数据库的基本功能外，gsql还提供了若干高级特性，便于用户使用。
1.使用gsql命令连接数据库

–使用omm用户连接到本机omm数据库的5432端口，命令中的-r选项提供了对gsql命令的历史版本支持。

su - omm
gsql -r
或
gsql -d omm  -p 5432  -r

root@modb:~#
root@modb:~# su - omm
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type “help” for help.

omm=# \q
omm@modb:~$ gsql -d omm -p 5432 -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type “help” for help.

omm=#

2.在gsql中查看数据库的版本、pg基础版本和版权信息

select version();
show server_version;
 \copyright

omm=# select version(); 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. omm=# show server_version; server_version ----.------------ 9.2.4 (1 row)

omm=# \copyright
GaussDB Kernel Database Management System
Copyright © Huawei Technologies Co., Ltd. 2018. All rights reserved.

omm=#

3.常见元命令的使用

--\l命令，元命令\l的作用是显示openGauss数据库集簇中，目前有哪些数据库。
\l

omm=# \l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privil
eges
—.--------±------±---------±--------±------±-------------
.-----
omm | omm | UTF8 | C | C |
postgres | omm | UTF8 | C | C |
template0 | omm | UTF8 | C | C | =c/omm
+
| | | | | omm=CTc/omm
template1 | omm | UTF8 | C | C | =c/omm
+
| | | | | omm=CTc/omm
(4 rows)

omm=#

--\conninfo命令，元命令\conninfo的作用是在gsql中，显示会话的连接信息。
\conninfo

omm=# \conninfo
You are connected to database “omm” as user “omm” via socket in “/tmp” at port “5432”.
omm=#

--\c[onnect] [DBNAME]命令，元命令\ c[onnect] [DBNAME]的作用是在gsql中，切换连接的数据库postgres。
\c postgres

omm=# \c postgres
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database “postgres” as user “omm”.
omm=#

--\du命令和\dg命令，元命令\dg命令与元命令\du命令的作用类似，都是显示openGauss数据库集簇中，目前有哪些用户和角色。
\du

\dg

--\db命令，元命令\db的作用是显示openGauss数据库集簇中，目前有哪些表空间。
\db

openGauss=#

--\dn命令，元命令\dn的作用是显示当前数据库有哪些数据库模式。
\dn

openGauss=#

--创建表
CREATE TABLE customer_t
(  c_customer_sk             integer,   
 c_customer_id             char(5),    
 c_first_name              char(6),    
 c_last_name               char(8) 
) ;

openGauss=# CREATE TABLE customer_t
openGauss-# ( c_customer_sk integer,
openGauss(# c_customer_id char(5),
openGauss(# c_first_name char(6),
openGauss(# c_last_name char(8)
openGauss(# ) ;
CREATE TABLE
openGauss=#

--插入数据
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES (3769, 5, 'Grace','White');

openGauss=# INSERT INTO customer_t (c_customer_sk, c_customer_iINSERT 0 1_name,c_last_name) VALUES (3769, 5, ‘Grace’,‘White’);
openGauss=#

–\dt命令，命令\dt的作用是显示数据库中所有的表。

\dt

openGauss=# \dt
List of relations
Schema | Name | Type | Owner | Storage

----.----±-----------±------±------±------------------------
–.-------
public | customer_t | table | omm | {orientation=row,compres
sion=no}
(1 row)

openGauss=#

--\d TableName命令，元命令\d TableName的作用是查看某个表的信息。
\d customer_t

openGauss=# \d customer_t

    Table "public.customer_t"
Column     |     Type     | Modifiers

openGauss=#

--\di IndexName命令，查看索引信息，元命令\di IndexName的作用是查看某个索引的信息。
create index idx_customer_id on customer_t(c_customer_id);
\di

openGauss=#

--可以用\pset命令以不同的方法显示表：
\pset border 2

SELECT * FROM customer_t;

\pset border 2openGauss=#
Border style is 2.

openGauss=# select * from customer_t;
±--------------±--------------±-------------±------------+
(1 row)

openGauss=#

--打开扩展表格式模式。
\x

openGauss=# \x
Expanded display is on.
openGauss=#

4.gsql中的事务：测试gsql中的默认事务自动提交功能

--查看gsql中事务是否默认为自动提交
show AUTOCOMMIT;
--测试gsql中事务默认为自动提交功能
create  table customer_new as select * from customer_t;
\q

--重新登录后看到之前创建的表customer_new：
gsql -d postgres  -p 5432  -r
\dt

openGauss=# show AUTOCOMMIT;
-[ RECORD 1 ]–
autocommit | on

openGauss=#
openGauss=# create table customer_new as select * from customer_t;
INSERT 0 1
openGauss=# \q
omm@modb:~$ gsql -r
gsql ((openGauss 3.0.0 build 02c14696) compiled at 2022-04-01 18:12:00 commit 0 last mr )
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type “help” for help.

omm=# \dt
List of relations
Schema | Name | Type | Owner | Storage
--------±-------------±------±------±---------------------------------
public | customer_new | table | omm | {orientation=row,compression=no}
public | customer_t | table | omm | {orientation=row,compression=no}
(2 rows)

omm=#

5.gsql中的事务：测试gsql中的事务手动提交功能

-–测试gsql手动提交
#Opengauss默认执行完一条语句后，立即提交。可以关闭自动提交功能：
#注意：此处设置ATUOCOMMIT必须用大写！

\set AUTOCOMMIT off
   --插入一些数据
INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES    
(6885, 1, 'Joes', 'Hunter'),    
(4321, 2, 'Lily','Carter'),    
(9527, 3, 'James', 'Cook'),
(9500, 4, 'Lucy', 'Baker');
  --查看表中数据
select * from customer_t;
--执行回滚
ROLLBACK;
    --检查是否回滚成功
SELECT * FROM customer_t;

omm=# \set AUTOCOMMIT off omm=# INSERT INTO customer_t (c_customer_sk, c_customer_id, c_first_name,c_last_name) VALUES omm-# (6885, 1, 'Joes', 'Hunter'), omm-# (4321, 2, 'Lily','Carter'), omm-# (9527, 3, 'James', 'Cook'), omm-# (9500, 4, 'Lucy', 'Baker'); INSERT 0 4 omm=# select *

omm=#

6.gsql相关的帮助

--连接数据库时，可以使用如下命令获取帮助信息。
gsql --help

--\h获取和SQL语法有关的帮助信息
\h

--\? 获取和元命令有关的帮助信息
 \？

omm-# \h

Available help:
ABORT BEGIN CREATE TABLESPACE DROP TEXT SEARCH CONFIGURATION
ALTER APP WORKLOAD GROUP CALL CREATE TEXT SEARCH CONFIGURATION DROP TEXT SEARCH DICTIONARY
ALTER APP WORKLOAD GROUP MAPPING CHECKPOINT CREATE TEXT SEARCH DICTIONARY DROP TRIGGER
ALTER AUDIT POLICY CLEAN CONNECTION CREATE TRIGGER DROP TYPE
ALTER DATA SOURCE CLOSE CREATE TYPE DROP USER
ALTER DATABASE CLUSTER CREATE USER DROP VIEW
ALTER DEFAULT PRIVILEGES COMMENT CREATE VIEW DROP WEAK PASSWORD DICTIONARY
ALTER DIRECTORY COMMIT CREATE WEAK PASSWORD DICTIONARY DROP WORKLOAD GROUP
ALTER EXTENSION COMMIT PREPARED CREATE WORKLOAD GROUP END
ALTER GLOBAL CONFIGURATION CREATE AUDIT POLICY DELETE FETCH
ALTER GROUP CREATE BARRIER DO GRANT
ALTER INDEX CREATE CLIENT MASTER KEY DROP APP WORKLOAD GROUP INSERT
ALTER MASKING POLICY CREATE DATA SOURCE DROP AUDIT POLICY MERGE
ALTER MATERIALIZED VIEW CREATE DATABASE DROP CLIENT MASTER KEY MOVE
ALTER NODE CREATE DIRECTORY DROP COLUMN ENCRYPTION KEY PREDICT BY
ALTER NODE GROUP CREATE EXTENSION DROP DATA SOURCE PREPARE
ALTER OPERATOR CREATE FOREIGN TABLE DROP DATABASE PREPARE TRANSACTION
ALTER PACKAGE CREATE FUNCTION DROP DIRECTORY PUBLISH SNAPSHOT
–More-- ALTER FOREIGN TABLE COPY CURSOR EXECUTE
ALTER FOREIGN TABLE FOR HDFS CREATE APP WORKLOAD GROUP DEALLOCATE EXECUTE DIRECT
ALTER FUNCTION CREATE APP WORKLOAD GROUP MAPPING DECLARE EXPLAIN
ALTER LARGE OBJECT CREATE COLUMN ENCRYPTION KEY DROP APP WORKLOAD GROUP MAPPING LOCK
ALTER PUBLICATION CREATE GROUP DROP EXTENSION PURGE
ALTER RESOURCE LABEL CREATE INDEX DROP FOREIGN TABLE PURGE SNAPSHOT
ALTER RESOURCE POOL CREATE LANGUAGE DROP FUNCTION REASSIGN OWNED
ALTER ROLE CREATE MASKING POLICY DROP GLOBAL CONFIGURATION REFRESH MATERIALIZED VIEW
ALTER ROW LEVEL SECURITY POLICY CREATE MATERIALIZED VIEW DROP GROUP REINDEX
ALTER SCHEMA CREATE MODEL DROP INDEX RESET
ALTER SEQUENCE CREATE NODE DROP MASKING POLICY REVOKE
ALTER SERVER CREATE NODE GROUP DROP MATERIALIZED VIEW ROLLBACK
ALTER SESSION CREATE OPERATOR DROP MODEL ROLLBACK PREPARED
ALTER SUBSCRIPTION CREATE PACKAGE DROP NODE SAMPLE SNAPSHOT
ALTER SYNONYM CREATE PACKAGE BODY DROP NODE GROUP SAVEPOINT
ALTER SYSTEM KILL SESSION CREATE PROCEDURE DROP OPERATOR SELECT
ALTER SYSTEM SET CREATE PUBLICATION DROP OWNED SELECT INTO
ALTER TABLE CREATE RESOURCE LABEL DROP PACKAGE SET
ALTER TABLE PARTITION CREATE RESOURCE POOL DROP PACKAGE BODY SET CONSTRAINTS
ALTER TABLE SUBPARTITION CREATE ROLE DROP PROCEDURE SET ROLE
ALTER TABLESPACE CREATE ROW LEVEL SECURITY POLICY DROP PUBLICATION SET SESSION AUTHORIZATION
ALTER TEXT SEARCH CONFIGURATION CREATE SCHEMA DROP RESOURCE LABEL SET TRANSACTION
ALTER TYPE CREATE SNAPSHOT AS DROP ROW LEVEL SECURITY POLICY TIMECAPSULE TABLE
ALTER USER CREATE SNAPSHOT FROM DROP SCHEMA TRUNCATE
ALTER VIEW CREATE SUBSCRIPTION DROP SEQUENCE UPDATE
–More-- ALTER TEXT SEARCH DICTIONARY CREATE SEQUENCE DROP RESOURCE POOL SHOW
ALTER TRIGGER CREATE SERVER DROP ROLE START TRANSACTION
ALTER WORKLOAD GROUP CREATE SYNONYM DROP SERVER VACUUM
ANALYSE CREATE TABLE DROP SUBSCRIPTION VALUES
ANALYZE CREATE TABLE AS DROP SYNONYM
ANONYMOUS BLOCK CREATE TABLE PARTITION DROP TABLE
ARCHIVE SNAPSHOT CREATE TABLE SUBPARTITION DROP TABLESPACE
omm-# ?
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
\qecho [STRING] write string to query output stream (see \o)
–More-- \ir+ FILE KEY as \i+, but relative to location of current script
\o [FILE] send all query results to file or |pipe

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
\db[+] [PATTERN] list tablespaces
\dc[S+] [PATTERN] list conversions
\dC[+] [PATTERN] list casts
\dd[S] [PATTERN] show object descriptions not displayed elsewhere
\ddp [PATTERN] list default privileges
\dD[S+] [PATTERN] list domains
\ded[+] [PATTERN] list data sources
\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[+] [PATTERN] list roles
\di[S+] [PATTERN] list indexes
\dl list large objects, same as \lo_list
–More-- \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
\ds[S+] [PATTERN] list sequences
\dt[S+] [PATTERN] list tables
\dT[S+] [PATTERN] list data types
\du[+] [PATTERN] list roles
\dv[S+] [PATTERN] list views
\dE[S+] [PATTERN] list foreign tables
\dx[+] [PATTERN] list extensions
\l[+] list all databases
\sf[+] FUNCNAME show a function’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
Variables
–More-- numericlocale|recordsep|recordsep_zero|tuples_only|title|tableattr|pager|
feedback})
\t [on|off] show only rows (currently off)
\T [STRING] set HTML

tag attributes, or unset if none
\x [on|off|auto] toggle expanded output (currently off)

Connection
\c[onnect] [DBNAME|- USER|- HOST|- PORT|-]
connect to new database (currently “omm”)
\encoding [ENCODING] show or set client encoding
\conninfo display information about current connection

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

\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 := {format|border|expanded|fieldsep|fieldsep_zero|footer|null|
\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
omm-# gsql --help

opengauss opengauss每日一练

最后修改时间：2022-11-29 21:03:06

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openGauss每日一练第2天 | 学习心得体会

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