/*
多行注释
*/
–数据的增删改查四个操作

use MySchool2
–查询所有数据 单行注释 --（两个减号）
select * from grade
–删除年级编号为2的信息
delete from Grade where GradeId =2
–插入一条语句
INSERT INTO Student
(StudentNo, LoginPwd, StudentName, Sex, GradeId, Phone, Address, BornDate, Email)
VALUES (‘A129’, ‘123456’, ‘张三’, ‘男’, 1, ‘139’, ‘bdqn’, ‘2001-02-12’, ‘zhagnsan@126.com’)
–更新:修改
UPDATE Grade SET GradeName=‘A119’