操作数据库基本用法

一，查询所有字段

select * from employee

二，查询指定字段

select ename from employee

三，给字段加别名

select ename AS 员工姓名 from employee

四，通过条件查询

select * from employee where id = 1

五，添加数据

insert into employee(id,ename,eage) values(default,'张三',18)

六，修改数据

update employee set ename = '李四' where id =1

七，删除数据

delete from employee where id = 1