--SELECT 列名称 FROM 表名称 WHERE 列 运算符 值
--select *from Student where sage<=19 and ssex!=‘M‘
--select *from Student where sage<=19 or ssex!=‘M‘
--SELECT * FROM Student WHERE (ssex=‘M‘ OR sage<20)AND sdept=‘CS‘
--SELECT  FROM Orders ORDER BY Company
--select *from Student order by sage
--SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber
--select *from Student order by sage,ssex  //正序排名
--select *from Student order by sage desc //逆序排名
--INSERT INTO table_name (列1, 列2,...) VALUES (值1, 值2,....)
--insert into Student(sno,sname,sage,ssex,sdept) values(95005,‘大猫‘,28,‘M‘,‘AV‘)  插入
--Update 语句用于修改表中的数据。
--update Student set sname=‘小孩‘ where sage<=18 //更新一列
--UPDATE Person SET Address = ‘Zhongshan 23‘, City = ‘Nanjing‘
--WHERE LastName = ‘Wilson‘
--update Student set sname=‘操蛋‘,ssex=‘F‘ where ssex=‘M‘  

sql 语句