openGauss每日一练第6天

今天学习openGauss创建模式、修改模式属性和删除模式
1.创建模式
–创建名为ds的模式

CREATE SCHEMA ds;

omm=# create schema ds;
omm=# CREATE SCHEMA

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–查看ds模式信息, owner为omm

\dn+ ds;

omm=# \dn+ ds;
List of schemas
Name | Owner | Access privileges | Description
------±------±------------------±------------
ds | omm | |
(1 row)

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2.在ds中建表
create table ds.t1(id int, name char(30));
insert into ds.t1 values(1 ,‘xxxx’);
select * from ds.t1;

omm=# create table ds.t1(id int,name char(30));
CREATE TABLE
omm=# insert into ds.t1 values(1,‘xxxx’);
INSERT 0 1
omm=# select * from ds.t1;
id | name
----±-------------------------------
1 | xxxx
(1 row)

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–查看表信息

\d+ ds.t1;

omm=# \d+ ds.t1;
Table “ds.t1”
Column | Type | Modifiers | Storage | Stats target | Description
--------±--------------±----------±---------±-------------±------------
id | integer | | plain | |
name | character(30) | | extended | |
Has OIDs: no
Options: orientation=row, compression=no

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3.修改模式信息
–重命名模式为ds_new

ALTER SCHEMA ds RENAME TO ds_new;
select * from ds_new.t1;

omm=# alter schema ds rename to ds_new;
ALTER SCHEMA
omm=# \dn
List of schemas
Name | Owner
-------------±------
cstore | omm
dbe_perf | omm
ds_new | omm
pkg_service | omm
public | omm
snapshot | omm
(6 rows)




omm=# select * from ds_new.t1;
id | name
----±-------------------------------
1 | xxxx
(1 row)
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–创建用户jack

CREATE USER jack PASSWORD ‘abcd@123’;

omm=# create user jack password ‘abcd@123’;
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE

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–将ds_new的所有者修改为jack

ALTER SCHEMA ds_new OWNER TO jack;

omm=# alter schema ds_new owner to jack;
ALTER SCHEMA


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–查看ds_new模式信息

\dn+ ds_new;

omm=# \dn+ ds_new
List of schemas
Name | Owner | Access privileges | Description
--------±------±------------------±------------
ds_new | jack | |
(1 row)

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4.删除模式
DROP SCHEMA ds_new;
–当schema非空时，如果要删除一个schema及其包含的所有对象，需要使用CASCADE关键字

DROP SCHEMA ds_new CASCADE;
DROP USER jack;

omm=# drop schema ds_new cascade;
NOTICE: drop cascades to table ds_new.t1
DROP SCHEMA
omm=# drop user jack;
omm=# DROP ROLE

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课后作业
1.创建一个名为tpcds的模式

omm=# create schema tpcds;
CREATE SCHEMA

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2.创建一个用户tim, 并将tpcds的owner修改为tim，且修改owner前后分别使用\dn+查看模式信息

omm=# create user tim password ‘abcd.1234’;
NOTICE: The encrypted password contains MD5 ciphertext, which is not secure.
CREATE ROLE
omm=# alter schema tpcds owner to tim;
ALTER SCHEMA
omm=# \dn+ tpcds;
List of schemas
Name | Owner | Access privileges | Description
-------±------±------------------±------------
tpcds | tim | |
(1 row)

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3.重命名tpcds为tpcds1

omm=# alter schema tpcds rename to tpcds1;
ALTER SCHEMA

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4.在模式tpcds1中建表customer、插入记录和查询记录

omm=# create table tpcds1.customer(id int,name varchar(30));
CREATE TABLE
omm=# insert into tpcds1.customer values(1,‘abcd’);
INSERT 0 1
omm=# select * from tpcds1.customer;
id | name
----±-----
1 | abcd
(1 row)

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5.删除模式tpcds1

omm=# drop table tpcds1.customer;
DROP TABLE
omm=# drop schema tpcds1;
DROP SCHEMA
omm=# drop user tim;
DROP ROLE

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