sql;">
-- 开窗函数：在结果集的基础上进一步处理(聚合操作)
-- Over函数,添加一个字段显示最大年龄
SELECT *,MAX(StuAge) OVER ( ) MaxStuAge
FROM dbo.Student;
-- Over函数,添加一个字段显示总人数
SELECT *,COUNT(StuID) OVER ( ) StuCount
FROM dbo.Student;
-- Partition By 分组统计数量
-- 根据性别分组后，统计
SELECT COUNT(*) OVER ( PARTITION BY StuSex ),*
FROM dbo.Student;
-- 根据班级分组后，统计、排序
SELECT COUNT(*) OVER ( PARTITION BY Class ORDER BY Height),*
FROM dbo.Student;
-- Over函数,添加一个字段显示平均身高
SELECT *,AVG(Height) OVER ( ) AgeHeight
FROM dbo.Student;
--Row_Rumber()
SELECT ROW_NUMBER() OVER ( ORDER BY StuID DESC ) RowNumber,*
FROM dbo.Student
--Row_Rumber() 实现分页效果
;
WITH T AS ( SELECT ROW_NUMBER() OVER ( ORDER BY StuID DESC ) RowNumber,*
FROM dbo.Student
)
SELECT *
FROM T
WHERE T.RowNumber BETWEEN 1 AND 3;
--Rank() 排名函数,名次相同，跳过
SELECT RANK() OVER ( ORDER BY Height ),*
FROM dbo.Student;
--DENSE_Rank() 排名函数，名次相同不跳过
SELECT DENSE_RANK() OVER ( ORDER BY Height ),*
FROM dbo.Student;
-- NTILE()函数，参数：记录总数/划分区域 = 每个区域数组，把记录序号放进数组 (平均分组)
SELECT NTILE(3) OVER ( ORDER BY StuSex ),*
FROM dbo.Student;
以上所述是小编给大家介绍的sql Server 2012 开窗函数，希望对大家有所帮助，如果大家有任何疑问欢迎给我留言，小编会及时回复大家的！
原文链接：https://www.f2er.com/mssql/62704.html