openGauss每日一练 | 3.1 openGauss创建、修改、删除数据库

课后作业

1.分别创建名为tpcc1和tpcc2的数据库

omm=# create database tpcc1;
CREATE DATABASE
omm=# create database tpcc2;
CREATE DATABASE

\l

2.将tpcc1数据库重命名为tpcc10

alter database tpcc1 rename to tpcc10;
\l

3.分别使用\l和\l+两个元命令查看数据库信息

\l+所查询信息要比\l的要更加详细，多出了Size、TableSpace、Description列。

omm=# \l+
                                                               List of databases
   Name    | Owner | Encoding |   Collate   |    Ctype    | Access privileges | Size  | Tablespace |                Description                 
-----------+-------+----------+-------------+-------------+-------------------+-------+------------+--------------------------------------------
 music2    | omm   | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                   | 10 MB | pg_default | 
 omm       | omm   | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                   | 10 MB | pg_default | 
 postgres  | omm   | UTF8     | en_US.UTF-8 | en_US.UTF-8 |                   | 10 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 | 
(7 rows)

omm=# \l
                              List of databases
   Name    | Owner | Encoding |   Collate   |    Ctype    | Access privileges 
-----------+-------+----------+-------------+-------------+-------------------
 music2    | omm   | UTF8     | en_US.UTF-8 | en_US.UTF-8 | 
 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 | 
(7 rows)

4.在数据库tpcc2中创建customer表，字段自定义

先用\c tpcc2命令切换到tpcc2库，然后用create命令创建库

omm=# \c tpcc2
Non-SSL connection (SSL connection is recommended when requiring high-security)
You are now connected to database "tpcc2" as user "omm".
tpcc2=# 
tpcc2=# create table customer(id int, name varchar(20));
CREATE TABLE

5.删除新创建的数据库

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;
omm=# DROP DATABASE
      
omm=# drop database tpcc10;
DROP DATABASE

6.退出gsql程序

omm=# \q
omm@modb:~$