sqlserver 模糊查询,连表,聚合函数,分组

 use StudentManageDB
 go
 select StudentName,StudentAddress from Students
 where StudentAddress like '天津%'

 select StudentName,StudentAddress from Students
 where StudentName like '%小%'

 select * from ScoreList
 where CSharp between 80 and 90

 select StudentName,StudentAddress,Birthday from Students
 where Birthday between '1987-01-01' and '1988-01-01'

 select StudentName,StudentAddress,age from Students
 where Age in(21,22,23)

 select StudentName,StudentAddress,age from Students
 where StudentName in('王小虎','贺小张')

 select SUM(CSharp) as C#总成绩 from ScoreList

 select 总人数=COUNT(*) from Students 

 select MAX(Csharp) as C#最高分 ,MIN(CSharp) as C#最低分,AVG(CSharp) as C#最低分 from ScoreList

 select Students.StudentId,C#成绩=CSharp,StudentName,ClassName
 from ScoreList
 inner join Students on  Students.StudentId=ScoreList.StudentId
 inner join StudentClass on Students.ClassId=StudentClass.ClassId
  where CSharp >80

 select  Students.StudentId,StudentName,Gender ,C#成绩=CSharp from Students
 left outer join ScoreList on Students.StudentId=ScoreList.StudentId
 where Gender='男'

 select  Students.StudentId,StudentName,Gender ,C#成绩=CSharp from ScoreList
 left outer join Students on Students.StudentId=ScoreList.StudentId
 where Gender='男'

 select 班级=StudentClass.ClassName,人数=COUNT(*),C#最高分=Max(CSharp),DB最高分=MAX(SQLServerDB),
 AVG(CSharp) as C#平均分,AVG(SQLServerDB) as DB平均分
 from Students
 inner Join StudentClass on Students.ClassId =StudentClass.ClassId
 inner join ScoreList on ScoreList.StudentId=Students.StudentId
 group by ClassName
 having AVG(CSharp)>=70 and AVG(SQLServerDB)>=70

 select * from ScoreList
 select StudentId from ScoreList group by StudentId  having COUNT(*)>1

 select * from ScoreList
 where StudentId in(select StudentId from ScoreList group by StudentId  having COUNT(*)>1)
 order by StudentId

 select * from ScoreList
 where (select COUNT(*) from ScoreList s where s.StudentId=ScoreList.StudentId)>1
 order by StudentId