SQL HierarchyId有时会产生错误的路径

Question

我有一个产品列表，使用HierarchyId进行排序，但对于某些项目，层次结构的完整路径产生了错误的结果。只有几...生病下面表明：

SELECT 
    ProductId 
    ,Name 
    ,FullName 
    ,Hierarchy 
    ,Hierarchy.ToString() as hierarchyString 
    ,editor.ufn_Product_GetFullName(ProductId) as ufnGetFullName 
    ,Hierarchy.GetLevel() as [level] 
FROM Editor.Product 
WHERE ProductId = 378 
    OR Hierarchy.ToString() like '/16/1/1/%' 
    OR Hierarchy.ToString() = '/16/1/' 
    OR Hierarchy.ToString() = '/16/' 
    OR Hierarchy.ToString() = '/' 
ORDER BY Hierarchy.ToString() 

使用该查询我得到的结果是：

大部分从过程返回的路径都很好，生产

'外部>渲染>颜色>白色'

然而其中四个产生最后两个交换PED像

“外观>渲染>白色>颜色”

我不能为我的生活，找出原因的条款进行交换，为什么只有一些。层次结构看起来正确，并且子级项目上的级别都是正确的。我需要你的帮助......

以下是用于从产品层次结构生成路径的功能，但我不明白它是如何成为问题的。

ALTER FUNCTION [Editor].[ufn_Product_GetFullName] (@ID INT) 
RETURNS VARCHAR(8000) 
AS BEGIN 
    -- Create and insert names into temp table 
    DECLARE @NamesTable TABLE (Name varchar(8000)); 

    INSERT @NamesTable (Name) 
     SELECT t1.Name 
     FROM ( SELECT ProductId, Hierarchy, Name 
       FROM Product WITH(NOLOCK) 
       WHERE (ProductId = @ID)) AS t2 
      CROSS JOIN Product AS t1 

     WHERE (t1.Hierarchy = t2.Hierarchy) 
     OR (t1.Hierarchy <> '/') 
     AND (t2.Hierarchy.IsDescendantOf(t1.Hierarchy) = 1) 

     ORDER BY t1.Hierarchy; 

    -- Define name string 
    DECLARE @Name VARCHAR(8000); 

    -- Coalesce names from temp table into one long string 
    SELECT @Name = COALESCE(@Name + ' > ', '') + Name 
    FROM @NamesTable 

    -- Return full string 
    RETURN @Name 
END 

Answer 1

没有ORDER BY条款你不能确定的行的次序。将表Level添加到@NamesTable表。将ORDER BY子句添加到SELECT您正在拼接字符串的位置。这应该有所帮助。

ALTER FUNCTION [Editor].[ufn_Product_GetFullName] (@ID INT) 
RETURNS VARCHAR(8000) 
AS BEGIN 
    -- Create and insert names into temp table 
    DECLARE @NamesTable TABLE (Name varchar(8000), Level int); 

    INSERT @NamesTable (Name, Level) 
     SELECT t1.Name, t1.Hierarchy.getLevel() 
     FROM ( SELECT ProductId, Hierarchy, Name 
       FROM Product WITH(NOLOCK) 
       WHERE (ProductId = @ID)) AS t2 
      CROSS JOIN Product AS t1 

     WHERE (t1.Hierarchy = t2.Hierarchy) 
     OR (t1.Hierarchy <> '/') 
     AND (t2.Hierarchy.IsDescendantOf(t1.Hierarchy) = 1) 

     ORDER BY t1.Hierarchy; 

    -- Define name string 
    DECLARE @Name VARCHAR(8000); 

    -- Coalesce names from temp table into one long string 
    SELECT @Name = COALESCE(@Name + ' > ', '') + Name 
    FROM @NamesTable 
    ORDER BY Level 

    -- Return full string 
    RETURN @Name 
END