T-SQL - 如何简化使用重复语句的查询

Question

我有一个查询，我试图简化，使用重复的代码... eek。我是一个SQL初学者（感觉我应该在出现之前把它放在那里！）。

基本上，模式有一个由3个组共享的数据池，我们称之为Parent，Child和GrandChild。父母可以有一个以上的孩子，孩子可以有一个以上的孙子。他们的数据存储在数据表中，并使用其ownerID进行链接。

这种模式不幸地使得向后查找数据变得困难。我想找到标签“Check me”的所有数据，其中dataText是'blahblah'。这要求我找到所有符合此标准的所有OwnerIds，然后从Data表中向后搜索，所有有这个guid的孙子，然后是所有孩子那个guid的GrandChildId等等。一旦我拥有所有ParentIds，我必须钻退缩。

无论如何，特别是我有兴趣删除重复的代码：

Select ParentId, DataFloat, DataText
  From [ Demo ] .Data
 Where ParentId In
      --get the data associated with the parents and union it with the children
       ((Select Guid
           from [ Demo ] .Parent
          where Guid In
                (Select Guid
                   From [ Demo ] .Parent
                  where Guid In
                        (Select ParentId
                           From [ Demo ] .Child
                          Where Guid In
                                (Select ChildId
                                   From [ Demo ] .GrandChild
                                  where Guid In
                                        (Select ParentId
                                           From [ Demo ] .Data
                                           Left join [ Demo ] .DataColumns as dc
                                             on [ Demo ].Data.DatumColumnId =
                                                dc.DatumColumnId
                                           Left join [ Demo ] .UserLabels as ul
                                             on dc.UserLabelId = ul.UserLabelId
                                            And ul.Label = N'Check me'
                                            And ul.Label is not null
                                          where DataText = N'blahblah')))))

        Union All
        --get the data associated with the children and union it with the grandchildren
        (Select Guid
           From [ Demo ] . [ Child ]
          Where SampleId In
                (Select Guid
                   From [ Demo ] .Parent
                  where Guid In
                        (Select ParentId
                           From [ Demo ] .Child
                          Where Guid In
                                (Select ChildId
                                   From [ Demo ] .GrandChild
                                  where Guid In
                                        (Select OwnerId
                                           From [ Demo ] .Data
                                           Left join [ Demo ] .DataColumns as dc
                                             on [ Demo ].Data.DatumColumnId =
                                                dc.DatumColumnId
                                           Left join [ Demo ] .UserLabels as ul
                                             on dc.UserLabelId = ul.UserLabelId
                                            And ul.Label = N'Check me'
                                            And ul.Label is not null
                                          where DataText = N'blahblah')))))

        Union all
        --get the data associated with the grandchildren
        (Select Guid
           From [ Demo ] . [ GrandChild ]
          Where ChildId IN
                (Select Guid
                   From [ Demo ] . [ Child ]
                  Where ParentId IN
                        (Select Guid
                           From [ Demo ] .Parent
                          where Guid In
                                (Select ParentId
                                   From [ Demo ] .Child
                                  Where Guid In
                                        (Select ChildId
                                           From [ Demo ] .GrandChild
                                          where Guid In
                                                (Select OwnerId
                                                   From [ Demo ] .Data
                                                   Left join [ Demo ] .DataColumns as dc
                                                     on [ Demo ]
                                                 .Data.DatumColumnId =
                                                        dc.DatumColumnId
                                                   Left join [ Demo ] .UserLabels as ul
                                                     on dc.UserLabelId =
                                                        ul.UserLabelId
                                                    And ul.Label = N'blahblah'
                                                    And ul.Label is not null
                                                  where DataText = N'blahblah')))))))

我尝试过子查询但没有成功。任何使这更容易的提示都会很棒。

由于