Question

是否可以透视表而无需汇总或汇总空值？

例如我有类似的查询

apiController.post(path,params) { response -> // Logic }}

导致

select 
    PERS_AREA_NAME,
    EMP_FIRST_NAME + ' ' + EMP_LAST_NAME as 'CHIEF COUNSEL',
    NULL AS 'APPROVER'
from 
    dbo.IES_HR_EMPLOYEES
where 
    JOB_NAME like '%Chf Cnsl%'  

UNION ALL  

select 
    PERS_AREA_NAME,
    NULL,
    EMP_FIRST_NAME + ' ' + EMP_LAST_NAME
from 
    dbo.IES_HR_EMPLOYEES
where
    JOB_NAME like '%Dep Sec%'
order by 
    1

是否可以汇总空值？

PERS_AREA_NAME CHIEF_COUNSEL APPROVER
-----------------------------------------
one            Bob Jones     Null
one            Fred Smith    Null
one            Null          Mary Smith
two            John Doe      Null
two            Null          Will Jones
two            Null          Fred Stevens

Answer 1

不是执行两个查询的全部UNION，而是使用ROW_NUMBER（）作为JOIN条件进行FULL OUTER JOIN。

Answer 2

对于您而言，我认为最好的方法是忘记多个子查询，而只是使用一种聚合形式：

select pers_area_name,
       max(chief_counsel) as chief_counsel,
       max(approver) as approver
from (select PERS_AREA_NAME, (EMP_FIRST_NAME + ' ' + EMP_LAST_NAME) as name,
             (CASE WHEN JOB_NAME like '%Chf Cnsl%' THEN name END) as chief_counsel,
             (CASE WHEN JOB_NAME like '%Dep Sec%' THEN name END) as approver,
             ROW_NUMBER() OVER (PARTITION BY (CASE WHEN JOB_NAME like '%Chf Cnsl%' THEN 1 ELSE 2 END)
                                ORDER BY (SELECT NULL)
                               ) as seqnum
      from dbo.IES_HR_EMPLOYEES e cross apply
           (values (EMP_FIRST_NAME + ' ' + EMP_LAST_NAME)) v(name)
      where JOB_NAME like '%Chf Cnsl%' OR JOB_NAME like '%Dep Sec%'
    ) e
group by PERS_AREA_NAME, seqnum;
order by 1;

其背后的想法比查询更简单。基本上，它只是在单个子查询中跟踪首席顾问和批准者。关键思想是row_number()（按职务）。这样，聚合就可以为结果集中的每一行选取值。

这确实假设一个人（雇员表中的行）没有包含“ Chf Cnsl”和“ Dep Sec”的职位。

SQL Server透视表而不进行汇总

2 个答案: