Question

给出以下递归查询：

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

我可以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department / item关系表中匹配的节点（在任何级别）。这些节点可能是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。

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，您只能在DepartmentItemRelationship表中添加具有匹配项的子节点。最后只获得至少有孩子的节点。

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)

Answer 2

如果我理解正确，您希望所有节点都高于叶级别一级？

您实际上并不需要递归查询。您所需要的只是首先找到叶子节点，然后选择所有父节点。

WITH LeafNodeParents AS
(
    SELECT DISTINCT ParentId
    FROM StoreDepartment
    WHERE DepartmentId NOT IN
    (
        SELECT DISTINCT ParentId FROM StoreDepartment
    )
)
SELECT d.DepartmentId, d.Name, d.IsInactive, d.IsSpecial, d.ParentId
FROM LeafNodeParents p
INNER JOIN StoreDepartment d
    ON d.DepartmentId = p.ParentId

唯一不会告诉你的是关卡。我不确定你需要多么糟糕。如果不这样做，这应该比递归版本更好;如果你这样做，看起来Jose的查询就可以了（通过快速浏览判断）。

递归查询 - 仅选择叶节点表示活动数据的节点

2 个答案: