Question

我有此输入表：

+-------------+--------------+-------+
| ProjectName | ProjectOwner | Col2  |
+-------------+--------------+-------+
| A           | Sara         | Sara  |
| B           | Jack         | Maria |
| B           | Jack         | Jack  |
| C           | Laura        | May   |
| C           | Laura        | Laura |
| D           | Paul         | Jack  |
| E           | May          | May   |
| E           | May          | May   |
+-------------+--------------+-------+

我想分别检查每个项目然后排除

如果项目所有者的名字在col2中，并且其他人与他同在，则删除重复的Jack Jack行，

a。例如，在Project B中，杰克的名字在Col2中，并且他正在与Maria一起工作，因此请删除Jack Jack

b。还要在项目C中删除Laura Laura
如果项目所有者仅自己在项目内部工作，则保留该项目，例如Project A和Project E
如果项目所有者的col2中没有他的名字，则排除项目D之类的项目
删除重复的项目，例如Project E

输出表：

+-------------+--------------+-------+
| ProjectName | ProjectOwner | Col2  |
+-------------+--------------+-------+
| A           | Sara         | Sara  |
| B           | Jack         | Maria |
| C           | Laura        | May   |
| E           | May          | May   | 
+-------------+--------------+-------+

我尝试了这个here，但结果没有向我显示Project A和E

Answer 1

请尝试以下代码：

select distinct  *
from mytable m
where (ProjectOwner!=Col2 or not exists(select 1 from mytable m1 where m1.ProjectName=m.ProjectName and  m1.ProjectOwner=m.ProjectOwner and m.Col2!=m1.Col2) )
and ProjectName in (select ProjectName from mytable where ProjectOwner=Col2 )

Demo

Answer 2

使用EXISTS和ROW_NUMBER()函数：

select top (1) with ties *
from table t
where exists (select 1 
              from table t1 
              where t1.ProjectName = t.ProjectName and 
                    t1.Col2 = t.ProjectOwner
             )
order by dense_rank() over (partition by ProjectName 
                            order by (case when t.ProjectOwner = Col2 
                                           then 1 else 0 
                                       end)
                           );

Answer 3

通过使用 GROUPING 和 COUNT 聚合，您可以通过此嵌套SQL获得所需的结果：

select ProjectName, ProjectOwner, Col2
  from
(  
   select ProjectName, ProjectOwner, Col2,
          count(1) over ( partition by ProjectName ) cnt
     from mytable
    group by ProjectName, ProjectOwner, Col2
) q
 where ( q.cnt = 1 or ProjectOwner != col2 )
   and ProjectOwner in ( select col2 from mytable );

SQL Fiddle Demo

如何根据SQL中的条件过滤出某些行

3 个答案: