管理之前先进入对应的数据库进行操作
mysql> use zx_mysql;
Database changed
mysql>
MySQL中,各个表代表着项目的子模块,比如用户表,用户状态表,公共信息表等,表的创建与删除只能通过管理员用户进行。
创建表:CREATE TABLE
SQL命令:
CREATE TABLE
mysql> CREATE TABLE users(
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`vname` varchar(20) DEFAULT NULL COMMENT '用户名',
`vpwd` varchar(50) DEFAULT NULL COMMENT '用户密码',
`add_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
PRIMARY KEY (`id`)
)ENGINE=InnoDB;
Query OK, 0 rows affected
mysql>
表字段说明
`vname` :字段名
varchar(20) :字段类型,长度
DEFAULT NULL :默认值,NULL
COMMENT '用户名' :注释
ENGINE=InnoDB :该表的存储引擎为InnoDB引擎
AUTO_INCREMENT=3 :可以添加指定自动递增的值,当前从3开始自动递增,默认从1开始自动递增。
查看表:SHOW TABLES
SQL命令:
SHOW TABLES;
mysql> SHOW TABLES;
+---------------------------+
| Tables_in_zx_mysql |
+---------------------------+
| users |
+---------------------------+
1 rows in set
查看表字段:SHOW COLUMNS FROM
SQL命令:
SHOW COLUMNS FROM <tablename>
或:
DESC <tablename>;
mysql> SHOW COLUMNS FROM zusers;
+-----------+-------------------+------+------+---------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-----------------+------+------+---------------------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| vname | varchar(20) | YES | | NULL | |
| vpwd | varchar(50) | YES | | NULL | |
| add_time | timestamp | NO | | CURRENT_TIMESTAMP | |
+-----------+-------------------+------+------+---------------------+----------------+
4 rows in set
字段信息:
Field :字段名
Type :字段类型
Null :是否允许空值
Key :键值
Default :默认值
Extra :其他信息,auto_increment自动递增
查询所有数据表:SHOW TABES
SQL命令:
SHOW TABES;
mysql> SHOW TABLES;
+-----------------------+
| Tables_in_zx_mysql |
+-----------------------+
| users |
+-----------------------+
1 row in set
修改表名字:RENAME
SQL命令:
ALTER TABLE <tablename> RENAME <new tablename>;
mysql> ALTER TABLE users RENAME zx_users;
Query OK, 0 rows affected
mysql> show tables;
+--------------------+
| Tables_in_zx_mysql |
+--------------------+
| zx_users |
+--------------------+
1 row in set
mysql>
删除表:DROP TABLE
SQL命令:
DROP TABLE <tablename>;
mysql> DROP TABLE zx_users;
Query OK, 0 rows affected
mysql>