–它有一个参数，用来指定桶数，例如
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SELECT ntile(2) OVER (ORDER BY B.SCORE DESC) AS GROUPID ,A.NAME, ISNULL(B.SCORE,0) SCORE, a.Id
FROM dbo.student AS a LEFT JOIN dbo.ScoreTB AS b ON a.Id = b.stuid AND scorename = ‘语文’
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–PARTITION BY 类似于向排名函数应用一个group by，分组后对每一个组单独排名
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–统计各个学科的排名依次为：
SELECT RANK() OVER (PARTITION BY b.scorename ORDER BY B.SCORE DESC) AS ROWNUMBER,b.scorename,
b.score, A.NAME, a.Id FROM dbo.student AS a INNER JOIN dbo.ScoreTB AS b ON a.Id = b.stuid ORDER BY SCORENAME
2. TOP 新用法
DECLARE @num INT = 101
SELECT TOP (@num) * FROM Student ORDER BY Id –必须用括号括起来
SELECT TOP (@num) percent * FROM Student ORDER BY Id –只接受float并且1-100之间的数，如果传入其他则会报错
3. group by all 字段 / group by 字段
前者有点像left join ,right join的感觉，两者的主要区别体现在有where条件被过滤的聚合函数，会重新抓取出来放入查询的数据表中，只是聚合函数会根据返回值的类型用默认值0或者NULL来代替聚合函数的返回值。
当然从效率上来说，后者优于前者，就像inner join 优于left join一样
4. count(*)/count(0) 与 count(字段)
如果查询出来的字段中没有NULL值，那么俩种查询条件无任何区别，如果有NULL，后者统计出来的记录则是 总记录数 – NULL记录数
从性能上来说，前者高于后者，因为后者会逐行扫描字段中是否有NULL值，有NULL则不加以统计，减少了逻辑读的开销，从而性能达到提升
5. top n With ties 的用法
详见 http://www.cnblogs.com/skynet/archive/2010/03/29/1700055.html
举个例子
select top 1 with ties * from student order by score desc
等价于
select * from student where score=(select top 1 score from student order by score desc)
6. Apply运算符
View Code
–准备数据
CREATE TABLE [dbo].[Student](
[Id] [int] NULL,
[Name] [varchar](50) NULL
)
go
INSERT INTO dbo.Student VALUES (1, ‘张三’)
INSERT INTO dbo.Student VALUES (2, ‘李斯’)
INSERT INTO dbo.Student VALUES (3, ‘王五’)
INSERT INTO dbo.Student VALUES (4, ‘神人’)
