概述
本文档记录openGauss 3.0.0数据库每日一练第11天课程作业，掌握创建数据库、删除数据库、重新命名数据库、查看数据库的信息。
课程练习
创建表空间enmtbs和数据库musicdb
omm@local:/opt/huawei/tmp [postgres]=#CREATE TABLESPACE enmtbs1 RELATIVE LOCATION 'tablespace/enmtbs1';
CREATE TABLESPACE
omm@local:/opt/huawei/tmp [postgres]=#CREATE DATABASE musicdb11 WITH TABLESPACE = enmtbs1;
CREATE DATABASE
查看数据库集簇中有哪些数据库
omm@local:/opt/huawei/tmp [postgres]=#SELECT datname FROM pg_database;
datname
-----------
template1
zsdba
template0
music_db
music_db1
music_db2
postgres
musicdb10
musicdb6
musicdb7
newdb1
newdb2
newdb3
newdb4
musicdb11
(15 rows)
omm@local:/opt/huawei/tmp [postgres]=#\l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+-------+-----------+---------+-------+-------------------
music_db | omm | SQL_ASCII | C | C |
music_db1 | omm | SQL_ASCII | C | C |
music_db2 | omm | SQL_ASCII | C | C |
musicdb10 | omm | SQL_ASCII | C | C |
musicdb11 | omm | SQL_ASCII | C | C |
musicdb6 | omm | SQL_ASCII | C | C |
musicdb7 | omm | SQL_ASCII | C | C |
newdb1 | omm | SQL_ASCII | C | C |
newdb2 | omm | SQL_ASCII | C | C |
newdb3 | omm | SQL_ASCII | C | C |
newdb4 | omm | SQL_ASCII | C | C |
postgres | omm | SQL_ASCII | C | C |
template0 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
zsdba | omm | SQL_ASCII | C | C |
(15 rows)
查看数据库默认的表空间信息
omm@local:/opt/huawei/tmp [postgres]=#select datname,dattablespace from pg_database where datname='musicdb11';
datname | dattablespace
-----------+---------------
musicdb11 | 24584
(1 row)
omm@local:/opt/huawei/tmp [postgres]=#select oid,spcname from pg_tablespace where oid=24584;
oid | spcname
-------+---------
24584 | enmtbs1
(1 row)
omm@local:/opt/huawei/tmp [postgres]=#select spcname
openGauss-# from pg_tablespace
openGauss-# where oid=( select dattablespace
openGauss(# from pg_database
openGauss(# where datname='musicdb11' );
spcname
---------
enmtbs1
(1 row)
查看数据库下有哪些模式
omm@local:/opt/huawei/tmp [postgres]=#\c musicdb11
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "musicdb11" as user "omm".
omm@local:/opt/huawei/tmp [musicdb11]=#\dn+
List of schemas
Name | Owner | Access privileges | Description | WithBlockChain
-----------------+-------+-------------------+----------------------------------+----------------
blockchain | omm | | blockchain schema | f
cstore | omm | | reserved schema for DELTA tables | f
db4ai | omm | omm=UC/omm +| db4ai schema | f
| | =U/omm | |
dbe_perf | omm | | dbe_perf schema | f
dbe_pldebugger | omm | omm=UC/omm +| dbe_pldebugger schema | f
| | =U/omm | |
dbe_pldeveloper | omm | omm=UC/omm +| dbe_pldeveloper schema | f
| | =U/omm | |
pkg_service | omm | | pkg_service schema | f
public | omm | omm=UC/omm +| standard public schema | f
| | =U/omm | |
snapshot | omm | | snapshot schema | f
sqladvisor | omm | omm=UC/omm +| sqladvisor schema | f
| | =U/omm | |
(10 rows)
omm@local:/opt/huawei/tmp [musicdb11]=#SELECT catalog_name, schema_name, schema_owner FROM information_schema.schemata;
catalog_name | schema_name | schema_owner
--------------+--------------------+--------------
musicdb11 | pg_toast | omm
musicdb11 | cstore | omm
musicdb11 | pkg_service | omm
musicdb11 | dbe_perf | omm
musicdb11 | snapshot | omm
musicdb11 | blockchain | omm
musicdb11 | pg_catalog | omm
musicdb11 | public | omm
musicdb11 | sqladvisor | omm
musicdb11 | dbe_pldebugger | omm
musicdb11 | dbe_pldeveloper | omm
musicdb11 | information_schema | omm
musicdb11 | db4ai | omm
(13 rows)
查询当前连接的数据库下有哪些表
omm@local:/opt/huawei/tmp [musicdb11]=#with my_tables(table_catalog, table_schema, table_name, table_type) as
musicdb11-# ( select table_catalog, table_schema, table_name, table_type
musicdb11(# from information_schema.tables
musicdb11(# where table_schema not in ('pg_catalog', 'information_schema','dbe_perf')
musicdb11(# )
musicdb11-#
musicdb11-# select * from my_tables;
table_catalog | table_schema | table_name | table_type
---------------+-----------------+------------+------------
musicdb11 | db4ai | snapshot | BASE TABLE
musicdb11 | dbe_pldeveloper | gs_errors | BASE TABLE
musicdb11 | dbe_pldeveloper | gs_source | BASE TABLE
musicdb11 | public | day11 | BASE TABLE
(4 rows)
更改数据库默认的表空间
omm@local:/opt/huawei/tmp [musicdb11]=#CREATE TABLESPACE app_ts2 RELATIVE LOCATION 'tablespace/app_ts2';
CREATE TABLESPACE
omm@local:/opt/huawei/tmp [musicdb11]=#ALTER DATABASE musicdb11 SET TABLESPACE app_ts2;
ERROR: cannot change the tablespace of the currently open database
omm@local:/opt/huawei/tmp [musicdb11]=#\c postgres
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "postgres" as user "omm".
omm@local:/opt/huawei/tmp [postgres]=#ALTER DATABASE musicdb11 SET TABLESPACE app_ts2;
ALTER DATABASE
omm@local:/opt/huawei/tmp [postgres]=#select spcname
openGauss-# from pg_tablespace
openGauss-# where oid=( select dattablespace
openGauss(# from pg_database
openGauss(# where datname='musicdb11' );
spcname
---------
app_ts2
(1 row)
重新命名数据库
omm@local:/opt/huawei/tmp [postgres]=#ALTER DATABASE musicdb11 RENAME TO musicdb112;
ALTER DATABASE
omm@local:/opt/huawei/tmp [postgres]=#\l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
------------+-------+-----------+---------+-------+-------------------
music_db | omm | SQL_ASCII | C | C |
music_db1 | omm | SQL_ASCII | C | C |
music_db2 | omm | SQL_ASCII | C | C |
musicdb10 | omm | SQL_ASCII | C | C |
musicdb112 | omm | SQL_ASCII | C | C |
musicdb6 | omm | SQL_ASCII | C | C |
musicdb7 | omm | SQL_ASCII | C | C |
newdb1 | omm | SQL_ASCII | C | C |
newdb2 | omm | SQL_ASCII | C | C |
newdb3 | omm | SQL_ASCII | C | C |
newdb4 | omm | SQL_ASCII | C | C |
postgres | omm | SQL_ASCII | C | C |
template0 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
zsdba | omm | SQL_ASCII | C | C |
(15 rows)
修改数据库的默认用户
omm@local:/opt/huawei/tmp [postgres]=#CREATE USER user11 IDENTIFIED BY 'zs@123456';
CREATE ROLE
omm@local:/opt/huawei/tmp [postgres]=#ALTER USER user11 SYSADMIN;
ALTER ROLE
omm@local:/opt/huawei/tmp [postgres]=#ALTER DATABASE musicdb112 OWNER to user11;
ALTER DATABASE
omm@local:/opt/huawei/tmp [postgres]=#\l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
------------+--------+-----------+---------+-------+-------------------
music_db | omm | SQL_ASCII | C | C |
music_db1 | omm | SQL_ASCII | C | C |
music_db2 | omm | SQL_ASCII | C | C |
musicdb10 | omm | SQL_ASCII | C | C |
musicdb112 | user11 | SQL_ASCII | C | C | <===============
musicdb6 | omm | SQL_ASCII | C | C |
musicdb7 | omm | SQL_ASCII | C | C |
newdb1 | omm | SQL_ASCII | C | C |
newdb2 | omm | SQL_ASCII | C | C |
newdb3 | omm | SQL_ASCII | C | C |
newdb4 | omm | SQL_ASCII | C | C |
postgres | omm | SQL_ASCII | C | C |
template0 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
zsdba | omm | SQL_ASCII | C | C |
(15 rows)
删除数据库
omm@local:/opt/huawei/tmp [postgres]=#DROP DATABASE musicdb112;
DROP DATABASE
omm@local:/opt/huawei/tmp [postgres]=#\l
List of databases
Name | Owner | Encoding | Collate | Ctype | Access privileges
-----------+-------+-----------+---------+-------+-------------------
music_db | omm | SQL_ASCII | C | C |
music_db1 | omm | SQL_ASCII | C | C |
music_db2 | omm | SQL_ASCII | C | C |
musicdb10 | omm | SQL_ASCII | C | C |
musicdb6 | omm | SQL_ASCII | C | C |
musicdb7 | omm | SQL_ASCII | C | C |
newdb1 | omm | SQL_ASCII | C | C |
newdb2 | omm | SQL_ASCII | C | C |
newdb3 | omm | SQL_ASCII | C | C |
newdb4 | omm | SQL_ASCII | C | C |
postgres | omm | SQL_ASCII | C | C |
template0 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
template1 | omm | SQL_ASCII | C | C | =c/omm +
| | | | | omm=CTc/omm
zsdba | omm | SQL_ASCII | C | C |
(14 rows)
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