1，创建表 

mysql> create table student(
    -> id int primary key,
    -> name varchar(20) not null,
    -> grade float
    -> );

插入记录

mysql> insert into student values(1,'monkey',98.5);
Query OK, 1 row affected (0.01 sec)

一次性插入多条记录

mysql> insert into student values(2,'bob',95.5),(3,'john',90.0),(4,'smith',88.5
);
Query OK, 3 rows affected (0.01 sec)
Records: 3  Duplicates: 0  Warnings: 0

部分数据插入

mysql> insert into student values(5,'jone',null);
Query OK, 1 row affected (0.01 sec)

修改值

mysql> update student set
    -> grade = grade+ 0.5 where grade > 90;
Query OK, 2 rows affected (0.01 sec)
Rows matched: 2  Changed: 2  Warnings: 0

创建用户，授予权限

mysql> create user test1@'localhost' identified by '123';
Query OK, 0 rows affected (0.02 sec)
mysql> grant select on db_system.student to test1@'localhost';
Query OK, 0 rows affected (0.01 sec)

查询权限

删除用户

mysql> drop user test1@'localhost';
Query OK, 0 rows affected (0.01 sec)