1.查看当前数据库下有哪些模式
--进入数据库omm，创建表空间、测试数据库
su - omm
gsql -r
drop DATABASE IF EXISTS musicdb;
CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
--执行下面的SQL语句，创建用户user1：
CREATE USER user1 IDENTIFIED BY 'Mygstest@1234';
--授予user1数据库系统的SYSADMIN权限：
ALTER USER user1 SYSADMIN;
--查看数据库下有哪些模式：
\dn
--除了可以用gsql的元命令\dn来查看数据库有哪些模式，还可以执行下面的SQL语句，查看某个数据库下有哪些模式：
SELECT catalog_name, schema_name, schema_owner FROM information_schema.schemata;
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=# drop DATABASE IF EXISTS musicdb;
NOTICE: database "musicdb" does not exist, skipping
DROP DATABASE
omm=# CREATE TABLESPACE music_tbs RELATIVE LOCATION 'tablespace/test_ts1';
CREATE TABLESPACE
omm=# CREATE DATABASE musicdb WITH TABLESPACE = music_tbs;
CREATE DATABASE
omm=# CREATE USER user1 IDENTIFIED BY 'Mygstest@1234';
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# ALTER USER user1 SYSADMIN;
ALTER ROLE
omm=# \q
omm@modb:~$ gsql -d musicdb -U user1 -p 5432 -W Mygstest@1234 -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.
musicdb=> \dn
List of schemas
Name | Owner
-----------------+-------
blockchain | omm
cstore | omm
db4ai | omm
dbe_perf | omm
dbe_pldebugger | omm
dbe_pldeveloper | omm
pkg_service | omm
public | omm
snapshot | omm
sqladvisor | omm
musicdb=> (10 rows)
musicdb=> SELECT catalog_name, schema_name, schema_owner FROM information_schema.schemata;
catalog_name | schema_name | schema_owner
--------------+--------------------+--------------
musicdb | pg_toast | omm
musicdb | cstore | omm
musicdb | pkg_service | omm
musicdb | dbe_perf | omm
musicdb | snapshot | omm
musicdb | blockchain | omm
musicdb | pg_catalog | omm
musicdb | public | omm
musicdb | sqladvisor | omm
musicdb | dbe_pldebugger | omm
musicdb | dbe_pldeveloper | omm
musicdb | information_schema | omm
musicdb | db4ai | omm
(13 rows)
musicdb=>
2.然后为数据库musicdb创建4个模式，名称自定义
--用户user1在数据库musicdb中，创建了4个模式：
create schema myschm1 AUTHORIZATION user1;
create schema myschm2 AUTHORIZATION user1;
create schema myschm3 AUTHORIZATION user1;
create schema myschm4 AUTHORIZATION user1;
musicdb=> create schema myschm1 AUTHORIZATION user1;
CREATE SCHEMA
musicdb=> create schema myschm2 AUTHORIZATION user1;
CREATE SCHEMA
musicdb=> create schema myschm3 AUTHORIZATION user1;
CREATE SCHEMA
musicdb=> create schema myschm4 AUTHORIZATION user1;
CREATE SCHEMA
musicdb=> \dn
List of schemas
Name | Owner
-----------------+-------
blockchain | omm
cstore | omm
db4ai | omm
dbe_perf | omm
dbe_pldebugger | omm
dbe_pldeveloper | omm
myschm1 | user1
myschm2 | user1
myschm3 | user1
myschm4 | user1
pkg_service | omm
public | omm
snapshot | omm
sqladvisor | omm
(14 rows)
musicdb=> SELECT catalog_name,schema_name,schema_owner FROM information_schema.schemata;
catalog_name | schema_name | schema_owner
--------------+--------------------+--------------
musicdb | pg_toast | omm
musicdb | cstore | omm
musicdb | pkg_service | omm
musicdb | dbe_perf | omm
musicdb | snapshot | omm
musicdb | blockchain | omm
musicdb | pg_catalog | omm
musicdb | public | omm
musicdb | sqladvisor | omm
musicdb | dbe_pldebugger | omm
musicdb | dbe_pldeveloper | omm
musicdb | information_schema | omm
musicdb | myschm2 | user1
musicdb | myschm3 | user1
musicdb | myschm4 | user1
musicdb | db4ai | omm
musicdb | myschm1 | user1
(17 rows)
musicdb=>
3.在数据库musicdb的不同的模式下创建同名的表
--在不同模式下，创建相同的表
create table myschm1.mytest1(product_id INTEGER,product_name Char(20),category Char(30));
create table myschm2.mytest2(product_id INTEGER,product_name Char(20),category Char(30));
create table myschm3.mytest3(product_id INTEGER,product_name Char(20),category Char(30));
create table myschm4.mytest4(product_id INTEGER,product_name Char(20),category Char(30));
--执行下面的SQL语句，往4个模式中的表分别插入一条数据：
--在同一个数据库下，可以直接使用SchemaName.TableName来指定一个表，可以省略数据库名。
musicdb=> insert into myschm1.mytest1 values(1501,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1701,'wait interface','Books'),(1801,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm2.mytest2 values(1502,'olympus camera','electrncs'),(1602,'lamaze','toys'),(1702,'wait interface','Books'),(1802,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm3.mytest3 values(1503,'olympus camera','electrncs'),(1603,'lamaze','toys'),(1703,'wait interface','Books'),(1803,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm4.mytest4 values(1504,'olympus camera','electrncs'),(1604,'lamaze','toys'),(1704,'wait interface','Books'),(1804,'harry potter','toys');
INSERT 0 4
musicdb=>
musicdb=> create table myschm1.mytest1(product_id INTEGER,product_name Char(20),category Char(30));
CREATE TABLE
musicdb=> create table myschm2.mytest2(product_id INTEGER,product_name Char(20),category Char(30));
CREATE TABLE
musicdb=> create table myschm3.mytest3(product_id INTEGER,product_name Char(20),category Char(30));
CREATE TABLE
musicdb=> create table myschm4.mytest4(product_id INTEGER,product_name Char(20),category Char(30));
CREATE TABLE
musicdb=> insert into myschm1.mytest1 values(1501,'olympus camera','electrncs'),(1601,'lamaze','toys'),(1701,'wait interface','Books'),(1801,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm2.mytest2 values(1502,'olympus camera','electrncs'),(1602,'lamaze','toys'),(1702,'wait interface','Books'),(1802,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm3.mytest3 values(1503,'olympus camera','electrncs'),(1603,'lamaze','toys'),(1703,'wait interface','Books'),(1803,'harry potter','toys');
INSERT 0 4
musicdb=> insert into myschm4.mytest4 values(1504,'olympus camera','electrncs'),(1604,'lamaze','toys'),(1704,'wait interface','Books'),(1804,'harry potter','toys');
INSERT 0 4
musicdb=>
4.访问musicdb数据库下不同模式的同名表
--访问musicdb数据库下其他模式的表，需要指定模式名前缀：
select * from myschm1.mytest1;
select * from myschm2.mytest2;
select * from myschm3.mytest3;
select * from myschm4.mytest4;
musicdb=> select * from myschm1.mytest1;
product_id | product_name | category
------------+----------------------+--------------------------------
1501 | olympus camera | electrncs
1601 | lamaze | toys
1701 | wait interface | Books
1801 | harry potter | toys
(4 rows)
musicdb=> select * from myschm2.mytest2;
product_id | product_name | category
------------+----------------------+--------------------------------
1502 | olympus camera | electrncs
1602 | lamaze | toys
1702 | wait interface | Books
1802 | harry potter | toys
(4 rows)
musicdb=> select * from myschm3.mytest3;
product_id | product_name | category
------------+----------------------+--------------------------------
1503 | olympus camera | electrncs
1603 | lamaze | toys
1703 | wait interface | Books
1803 | harry potter | toys
(4 rows)
musicdb=> select * from myschm4.mytest4;
product_id | product_name | category
------------+----------------------+--------------------------------
1504 | olympus camera | electrncs
1604 | lamaze | toys
1704 | wait interface | Books
1804 | harry potter | toys
(4 rows)
musicdb=>
5.实验理解：模式是在数据库层面，用户是在实例层面
--登录musicdb数据库，查看用户和模式
gsql -d musicdb -U user1 -p 5432 -W Mygstest@1234 -r
\du
\dn
\q
--登录omm数据库，查看用户和模式
gsql -r
\du
\dn
\q
omm@modb:~$ gsql -d musicdb -U user1 -p 5432 -W Mygstest@1234 -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.
musicdb=> \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------------------------------------------------------------+-----------
gaussdb | Sysadmin | {}
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
user1 | Sysadmin | {}
musicdb=> \dn
List of schemas
Name | Owner
-----------------+-------
blockchain | omm
cstore | omm
db4ai | omm
dbe_perf | omm
dbe_pldebugger | omm
dbe_pldeveloper | omm
myschm1 | user1
myschm2 | user1
myschm3 | user1
myschm4 | user1
pkg_service | omm
public | omm
snapshot | omm
sqladvisor | omm
(14 rows)
musicdb=> \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=# \du
List of roles
Role name | Attributes | Member of
-----------+------------------------------------------------------------------------------------------------------------------+-----------
omm | Sysadmin, Create role, Create DB, Replication, Administer audit, Monitoradmin, Operatoradmin, Policyadmin, UseFT | {}
user1 | Sysadmin | {}
gaussdb | Sysadmin | {}
omm=# \dn
List of schemas
Name | Owner
-----------------+-------
blockchain | omm
cstore | omm
db4ai | omm
dbe_perf | omm
dbe_pldebugger | omm
dbe_pldeveloper | omm
pkg_service | omm
public | omm
snapshot | omm
sqladvisor | omm
user1 | user1
(11 rows)
omm=# \q
omm@modb:~$
最后修改时间：2022-12-03 16:29:40
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