管理数据库

1. 创建数据库

mysql> create database db1;
Query OK, 1 row affected (0.01 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| db1                |
| hellodb            |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
6 rows in set (0.00 sec)

mysql> 
mysql> show create database db1;
+----------+-------------------------------------------------------------------------------------------------------------------------------+
| Database | Create Database                                                                                                               |
+----------+-------------------------------------------------------------------------------------------------------------------------------+
| db1      | CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */ |
+----------+-------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)



# 指定字符集创建新数据库
mysql> create database if not exists db2 character set 'utf8mb4';
Query OK, 1 row affected (0.01 sec)

简写
mysql> create database db3 charset=utf8mb4;
Query OK, 1 row affected (0.02 sec)

2. 修改数据库

mysql> alter database db1 character set utf8;
Query OK, 1 row affected, 1 warning (0.02 sec)

mysql> show create database db1;
+----------+----------------------------------------------------------------------------------------------------+
| Database | Create Database                                                                                    |
+----------+----------------------------------------------------------------------------------------------------+
| db1      | CREATE DATABASE `db1` /*!40100 DEFAULT CHARACTER SET utf8mb3 */ /*!80016 DEFAULT ENCRYPTION='N' */ |
+----------+----------------------------------------------------------------------------------------------------+
1 row in set (0.01 sec)

3. 删除数据库

mysql> drop database db1;
Query OK, 0 rows affected (0.17 sec)

4. 查看数据库列表

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| db2                |
| db3                |
| hellodb            |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
7 rows in set (0.00 sec)