Sql server 递归查询SQL Server未按预期工作

提前谢谢你的帮助。我对MSSQLSDB还是很陌生，但我想知道为什么下面对MSSQL的递归查询没有返回我期望的值。我已经做了我的研究，在底部是我提出的代码。假设我有下表

CategoryID    ParentID    SomeName
1             0           hmm
2             0           err
3             0           woo
4             3           ppp
5             4           ttt

我希望下面的查询返回3 4 5。我基本上是想根据我在递归查询中传递的类别id，在其下方获得类别id的继承权列表。谢谢你的帮助

GO
WITH RecursiveQuery (CategoryID)
AS
(
-- Anchor member definition
    SELECT a.CategoryID 
    FROM [SomeDB].[dbo].[SomeTable] AS a
    WHERE a.ParentID = CategoryID 
    UNION ALL
-- Recursive member definition
    SELECT b.CategoryID
    FROM [SomeDB].[dbo].[SomeTable] AS b
    INNER JOIN RecursiveQuery AS d
        ON d.CategoryID = b.ParentID
)
-- Statement that executes the CTE
SELECT o.CategoryID
FROM [SomeDB].[dbo].[SomeTable] AS o
INNER JOIN RecursiveQuery AS d
    ON d.CategoryID = 3
GO

---

如果要从特定根目录创建树，请执行以下操作：

DECLARE @rootCatID int = 3

;WITH LessonsTree (CatID)
AS
(
    SELECT a.CategoryID
    FROM [EducationDatabase].[dbo].[LessonCategory] AS a
    WHERE a.CategoryID = @rootCatID ---<<<

    UNION ALL

    SELECT b.CategoryID
    FROM LessonsTree as t
    INNER JOIN [EducationDatabase].[dbo].[LessonCategory] AS b
        ON b.ParentID = t.CatID
)
SELECT o.*
FROM LessonsTree t
INNER JOIN [EducationDatabase].[dbo].[LessonCategory] AS o
    ON o.CategoryID = t.CatID

---

如果要从特定根目录创建树，请执行以下操作：

DECLARE @rootCatID int = 3

;WITH LessonsTree (CatID)
AS
(
    SELECT a.CategoryID
    FROM [EducationDatabase].[dbo].[LessonCategory] AS a
    WHERE a.CategoryID = @rootCatID ---<<<

    UNION ALL

    SELECT b.CategoryID
    FROM LessonsTree as t
    INNER JOIN [EducationDatabase].[dbo].[LessonCategory] AS b
        ON b.ParentID = t.CatID
)
SELECT o.*
FROM LessonsTree t
INNER JOIN [EducationDatabase].[dbo].[LessonCategory] AS o
    ON o.CategoryID = t.CatID

---

如评论中所述，主播不受限制。最简单的解决方案是在锚中添加准则

with RecursiveQuery (theID)
AS
(
    SELECT a.ParentID --root id=parentid to include it and to prevent an extra trip to LessonCategory afterwards
    FROM  [LessonCategory] AS a
    WHERE a.ParentID = 3 --restriction here
    UNION ALL
    SELECT b.CategoryID
    FROM [LessonCategory] AS b
    INNER JOIN RecursiveQuery AS d
        ON d.theID = b.ParentID
)
SELECT* from RecursiveQuery

另一种选择是让递归查询是通用的，不受限制的锚，并让它保留rootid。然后cte上的查询可以限制rootid。第一个选项可能更好，第二个选项主要适用于创建某种根视图的情况

with RecursiveQuery 
AS
(
    SELECT a.ParentID theID, a.ParentID RootID
    FROM  [LessonCategory] AS a    
    UNION ALL
    SELECT b.CategoryID, d.RootID
    FROM [LessonCategory] AS b
    INNER JOIN RecursiveQuery AS d
        ON d.theID = b.ParentID
)
SELECT theID from RecursiveQuery where RootID = 3

---

如评论中所述，主播不受限制。最简单的解决方案是在锚中添加准则

with RecursiveQuery (theID)
AS
(
    SELECT a.ParentID --root id=parentid to include it and to prevent an extra trip to LessonCategory afterwards
    FROM  [LessonCategory] AS a
    WHERE a.ParentID = 3 --restriction here
    UNION ALL
    SELECT b.CategoryID
    FROM [LessonCategory] AS b
    INNER JOIN RecursiveQuery AS d
        ON d.theID = b.ParentID
)
SELECT* from RecursiveQuery

另一种选择是让递归查询是通用的，不受限制的锚，并让它保留rootid。然后cte上的查询可以限制rootid。第一个选项可能更好，第二个选项主要适用于创建某种根视图的情况

with RecursiveQuery 
AS
(
    SELECT a.ParentID theID, a.ParentID RootID
    FROM  [LessonCategory] AS a    
    UNION ALL
    SELECT b.CategoryID, d.RootID
    FROM [LessonCategory] AS b
    INNER JOIN RecursiveQuery AS d
        ON d.theID = b.ParentID
)
SELECT theID from RecursiveQuery where RootID = 3

---

其中a.ParentID=0，其中b.ParentID=d.thei，我猜最终的选择可能来自递归查询。d、 ID不会产生横切值3，它将是所有ID的列表。所以filter=3将给您一条记录。正如@IvanStarostin所说，您的锚定成员定义没有锚定到记录。锚点应该是一条作为起点的记录。好的，谢谢，我认为锚点是终止条件好的，我的错误将尝试一下…其中a.ParentID=0，其中b.ParentID=d。我猜最终选择可能来自递归查询。d、 ID不会产生横切值3，它将是所有ID的列表。所以filter=3将给您一条记录。正如@IvanStarostin所说，您的锚定成员定义没有锚定到记录。锚应该是一条记录，作为你的起点。好的，谢谢我认为锚是终止条件好的，我的错误会尝试一下…@debonaire如果是，你应该把它标记为答案。谢谢，现在就可以了。你能批准对变量名的编辑吗much@debonaire如果答案是，你应该把它标记为答案。谢谢，现在就可以了。你能批准变量名的编辑吗非常感谢你的建议。我会考虑到这一点。干杯非常感谢你的建议。我会考虑到这一点。干杯