openGauss每日一练第三天

openGauss 每日一练第三天

本文出处：https://www.modb.pro/db/193083

学习目标

学习 openGauss 创建数据库、修改数据库属性和删除数据库

课后作业

1.分别创建名为 tpcc1 和 tpcc2 的数据库

SQL文本：

create database tpcc1;

create database tpcc2;

\l

omm=# create database tpcc1;

CREATE DATABASE

omm=# create database tpcc2;

CREATE DATABASE

omm=# omm=# \l

List of databases

Name | Owner | Encoding | Collate | Ctype | Access privileges

-----------+-------+----------+-------------+-------------+-------------------

omm | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

postgres | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

template0 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +

| | | | | omm=CTc/omm

template1 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +

| | | | | omm=CTc/omm

tpcc1 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

tpcc2 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

(6 rows)

omm=#

2.将 tpcc1 数据库重命名为 tpcc10

SQL文本：

alter database tpcc1 rename to tpcc10;

omm=# alter database tpcc1 rename to tpcc10;

ALTER DATABASE

omm=#

3.分别使用\l 和\l+两个元命令查看数据库信息

SQL文本：

\l

\l+

omm=# \l

List of databases

Name | Owner | Encoding | Collate | Ctype | Access privileges

-----------+-------+----------+-------------+-------------+-------------------

omm | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

postgres | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

template0 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +

| | | | | omm=CTc/omm

template1 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +

| | | | | omm=CTc/omm

tpcc10 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

tpcc2 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 |

(6 rows)

omm=# \l+

List of databases

Name | Owner | Encoding | Collate | Ctype | Access privileges | Size | Tablespace | Description

-----------+-------+----------+-------------+-------------+-------------------+-------+------------+--------------------------------------------

omm | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 11 MB | pg_default |

postgres | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 41 MB | pg_default | default administrative connection database

template0 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +| 10 MB | pg_default | default template for new databases

| | | | | omm=CTc/omm | | |

template1 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/omm +| 10 MB | pg_default | unmodifiable empty database

| | | | | omm=CTc/omm | | |

tpcc10 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 10 MB | pg_default |

tpcc2 | omm | UTF8 | en_US.UTF-8 | en_US.UTF-8 | | 10 MB | pg_default |

(6 rows)

omm=#

4.在数据库 tpcc2 中创建 customer 表，字段自定义

SQL文本：

\c tpcc2

create table customer_t

(c_customer_sk integer,

c_customer_id char(5),

c_first_name char(6),

c_last_name char(8)

) ;

\d

tpcc2=# \c tpcc2

Non-SSL connection (SSL connection is recommended when requiring high-security)

You are now connected to database "tpcc2" as user "omm".

tpcc2=# create table customer_t

tpcc2-# (c_customer_sk integer,

tpcc2(# c_customer_id char(5),

tpcc2(# c_first_name char(6),

tpcc2(# c_last_name char(8)

tpcc2(# ) ;

CREATE TABLE

tpcc2=# \d

List of relations

Schema | Name | Type | Owner | Storage

---------+------------+-------+-------+----------------------------------

schema2 | customer_t | table | omm | {orientation=row,compression=no}

(1 row)

tpcc2=#

5.删除新创建的数据库

SQL文本：

\c omm

drop database tpcc2;

drop database tpcc10;

tpcc2=# \c omm

Non-SSL connection (SSL connection is recommended when requiring high-security)

You are now connected to database "omm" as user "omm".

omm=# drop database tpcc2;

DROP DATABASE

omm=# drop database tpcc10;

DROP DATABASE

omm=#

6.退出 gsql 程序

SQL文本：

\q

omm=# \q

[omm@modb ~]$