我试图掌握将表数据操作为更具视觉吸引力的输出格式.这可能是问题的一部分,因为我想要的可能是用于单独的报告软件.
我有一张看起来像这样的桌子
teacher student ---------------------- teacher1 Bob teacher1 Jim teacher2 Sam teacher3 Bill teacher3 John teacher3 Eric
我想要一个看起来像这样的表：
teacher1 teacher2 teacher3 --------------------------------- Bob Sam Bill Jim null John null null Eric
所以我尝试在变量中填充所有教师名称,然后使用Pivot,但由于我必须选择聚合,所以我只能得到这样的Max或Min学生：
DECLARE @teacherList AS VARCHAR(max)
SELECT @teacherList = Stuff((SELECT DISTINCT',[' + teacher + ']'
FROM myTable
FOR xml path('')),1,'')
DECLARE @dynamic_pivot_query AS VARCHAR(max)
SET @dynamic_pivot_query = 'select' + @teacherList +
'from
(
SELECT [teacher],[student]
FROM [dbo].[myTable]
) as S
Pivot
(
MIN([student])
FOR teacher IN (' + @teacherList + ')
) as P
'
EXEC(@dynamic_pivot_query)
结果是：
teacher1 teacher2 teacher3 --------------------------------- Bob Sam Bill
假设如下：
>教师#及其姓名未知(可变)
>每位教师的学生人数不详,每位教师可能也不同
有没有办法做到这一点？
解决方法
您可以使用row_number来获得所需的结果.
SET @dynamic_pivot_query = 'select ' + @teacherList +
'from
(
SELECT [teacher],[student],row_number() over(partition by teacher order by student) as rn
FROM [dbo].[myTable]
) as S
Pivot
(
MIN([student])
FOR teacher IN (' + @teacherList + ')
) as P
'
更新：
要删除sql注入漏洞,您应该使用引号来正确引用您的字段列表.
SELECT @teacherList = Stuff((SELECT DISTINCT',' + quotename(teacher)
FROM myTable
FOR xml path('')),'')
