13.基础-sql-dml- 更新和删除-爱代码爱编程
修改数据
-- 修改id为1的数据,将name修改为itheima
update employee set name ='itheima' where id = '1';
-- 修改id为1的数据,将name修改为小昭,gender修改为女
update employee set name ='小昭' ,gender = '女 'where id = '1';
-- 将所有的员工入职日期修改为2008-01-01
update employee set entrydate ='2008-01-01' ;
删除数据
-- 修改id为1的数据,将name修改为itheima
update employee set name ='itheima' where id = '1';
-- 修改id为1的数据,将name修改为小昭,gender修改为女
update employee set name ='小昭' ,gender = '女 'where id = '1';
-- 将所有的员工入职日期修改为2008-01-01
update employee set entrydate ='2008-01-01' ;
update employee set workno =4 where name = '哈哈哈';
-- 删除gender为女的员工
delete from employee where gender = '女';
-- 删除所有员工
delete from employee ;