递归查询 - 仅选择叶节点表示活动数据的节点

Question

给定以下递归查询:

WITH DepartmentHierarchy (DepartmentID, Name, IsInactive, IsSpecial, ParentId, HierarchyLevel) AS
(
   -- Base case
   SELECT
      DepartmentId,
      Name,
      IsInactive,
      IsSpecial,
      ParentId,
      1 as HierarchyLevel
   FROM StoreDepartment
   WHERE ParentId IS NULL

   UNION ALL

   -- Recursive step
   SELECT
      d.DepartmentId,
       d.Name,
      d.IsInactive,
      d.IsSpecial,
      d.ParentId,
      dh.HierarchyLevel + 1 AS HierarchyLevel
   FROM StoreDepartment d
      INNER JOIN DepartmentHierarchy dh ON
         d.ParentId = dh.DepartmentId
) SELECT * FROM DepartmentHierarchy 

我能够选择看起来像这样的数据:

DepartmentId, Name, IsInactive, IsSpecial, ParentId, HeirarchyLevel
1, Store, 0, 0, NULL, 1
2, Main Department 1, 0, 1, 2
3, Main Department 2, 0, 1, 2
4, Sub For Main 1, 0, 2, 3

此外,假设存在DepartmentId和ItemId的表(例如:DepartmentItemRelationship).部门层次结构中的叶节点与此处的项目配对.

我希望我的递归查询只返回在其下面至少有一个叶子节点并且在部门/项目关系表中匹配的节点(在任何级别).这些节点可能会降低6或7级,所以我不确定如何修改我的查询以确保包含这些节点.

谢谢,凯尔

Answer 1

您可以创建一个跟踪层次结构的路径列。然后，您只能添加在 DepartmentItemRelationship 表中具有匹配项的子节点。最后只获取至少有一个子节点的节点。

尝试这样的事情：

    WITH DepartmentHierarchy (DepartmentID, Name, IsInactive, IsSpecial, ParentId, HierarchyLevel) AS
(
   -- Base case
   SELECT
      '/'+cast( DepartmentId as varchar(max)) as [path]
      DepartmentId,
      Name,
      IsInactive,
      IsSpecial,
      ParentId,
      1 as HierarchyLevel
   FROM StoreDepartment
   WHERE ParentId IS NULL

   UNION ALL

   -- Recursive step
   SELECT
      dh.[path] +'/'+ cast( d.DepartmentId as varchar(max)) as [path]
      d.DepartmentId,
      d.Name,
      d.IsInactive,
      d.IsSpecial,
      d.ParentId,
      dh.HierarchyLevel + 1 AS HierarchyLevel
   FROM StoreDepartment d
      INNER JOIN DepartmentHierarchy dh ON
         d.ParentId = dh.DepartmentId
   where exists ( select top 1 1 
                  from DepartmentItemRelationship di
                  where di.DepartmentId = d.DepartmentId )
) 
SELECT * 
FROM DepartmentHierarchy dh
where exists ( select top 1 1 
               from DepartmentHierarchy 
               where charindex('/'+dh.DepartmentID+'/',[path]) > 0)