Question

我有一个产品列表，使用HierarchyId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。仅限少数......我将在下面展示：

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()

使用该查询我获得结果：

它从程序返回的大多数路径都很好，产生

＆＃39;外观＆gt;渲染＆gt;颜色＆gt;白＆＃39;

然而，其中有四个产生了最后两个交换的术语，如

＆＃39;外观＆gt;渲染＆gt;白色＆gt;色＆＃39;

我不能为我的生活，弄清楚为什么条款被交换，为什么只有一些。层次结构看起来正确，并且子项的级别都是正确的。我需要你的帮助......

以下是用于从产品层次结构生成路径的函数，但我不了解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

如果没有ORDER BY子句，则无法确定行顺序。将列Level添加到@NamesTable表。将ORDER BY子句添加到正在连接字符串的SELECT。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

SQL HierarchyId有时会产生错误的路径

1 个答案: