MySQL基本操作{记录1}{查看,选择,创建,修改,删除}
1,启动MySQL
终端输入
mysql -u root -p
然后输入密码,启动成功
Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 12 Server version: 8.0.28-0ubuntu0.20.04.3 (Ubuntu) Copyright (c) 2000, 2022, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql>
2,基本操作
2.1查看MySQL下的所有数据库
SHOW DATABASES;
2.2选择要操作的数据库:use 数据库名;
比如我们要使用数据库work
use work;
mysql> use work; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed
此后我们的所有操作都针对work
2.3创建数据库:使用create命令
CREATE DATABASE 数据库名;
例如我们要创建一个名为work的数据库
CREATE DATABASE work;
如果work数据库不存在则创建,如果存在则不会创建
work已存在,显示如下信息
mysql> CREATE DATABASE work; ERROR 1007 (HY000): Can't create database 'work'; database exists
2.4查看某个数据库 使用LIKE从句,他用于匹配指定的数据库名称
SHOW DATABASES LIKE '数据库名';
例如我们要查看数据库work
SHOW DATABASES LIKE 'work';
mysql> SHOW DATABASES LIKE 'work'; +-----------------+ | Database (work) | +-----------------+ | work | +-----------------+ 1 row in set (0.00 sec)
2.4查看某数据库的信息(定义声明)
SHOW CREATE DATABASE 数据库名;
查看work的信息(定义声明)
SHOW CREATE DATABASE work;
mysql> SHOW CREATE DATABASE work; +----------+--------------------------------------------------------------------------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------------------------------------------------------------------------+ | work | CREATE DATABASE `work` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */ | +----------+--------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)
2.5修改数据库
ALTER DATABASE 数据库名
终端下:
mysql> ALTER DATABASE 数据库名 -> DEFAULT CHARACTER SET 字符集名 -> DEFAULT COLLATE 校对规则名;
对work数据库进行修改
查看:
SHOW CREATE DATABASE work; +----------+--------------------------------------------------------------------------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------------------------------------------------------------------------+ | work | CREATE DATABASE `work` /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */ | +----------+--------------------------------------------------------------------------------------------------------------------------------+
修改:
mysql> ALTER DATABASE work -> DEFAULT CHARACTER SET gb2312 -> DEFAULT COLLATE gb2312_chinese_ci; Query OK, 1 row affected (0.02 sec)
再次查看:修改成功
mysql> SHOW CREATE DATABASE work; +----------+----------------------------------------------------------------------------------------------------+ | Database | Create Database | +----------+----------------------------------------------------------------------------------------------------+ | work | CREATE DATABASE `work` /*!40100 DEFAULT CHARACTER SET gb2312 */ /*!80016 DEFAULT ENCRYPTION='N' */ | +----------+----------------------------------------------------------------------------------------------------+
2.6删除数据库,使用DORP命令(谨慎使用)不能删除MySQL安装时自己创建的数据库
命令格式:
DROP DATABASE 数据库名;
例:删除work_tb1
DROP DATABASE work_tb1;
mysql> DROP DATABASE work_tb1; Query OK, 0 rows affected (0.02 sec)