mysql语句

//创建表：CREATE TABLE tbl_user(user_name VARCHAR(20),    age INT,    signup_date DATE    );//向表中插入一条记录insert into tbl_user values("zhangsan",28,"2017-07-22");insert into tbl_user values("lisi",30,"2017-07-22");//查看表中数据select * from tbl_user; //查看表中的某些字段select user_name,age from tbl_user;//使用where条件对查询结果进行过滤select * from tbl_user where user_name = "zhangsan";//使用多个查询条件查询结果select * from tbl_user where user_name = "zhangsan" and age = 28;//对字段进行更新update tbl_user set age = 38 where user_name = "zhangsan";//删除记录delete from tbl_user where user_name = "zhangsan";//在表中添加一个字段alter table tbl_user add email varchar(50);//在表中删除一个字段alter table tbl_user drop email;//重命名指定的列名(重命名字段名称)alter table tbl_user change age user_age int;//修改列的类型定义alter table tbl_user change user_age tinyint(1) not null;//重命名表名alter table tbl_user rename user_tbl;//删除表drop table user_tbl;