递归查询排序

Question

我有一个标准的表，这sotres父，子类别关系...像这样。

id, parent, catName, sort 

而且我用下面的查询来创建一个递归树

;WITH cte AS (
    SELECT 0 AS lvl, id, catName, parent,levels,sort, 
     CAST(id AS VARCHAR(128)) AS path 
    FROM CategoriesMap WHERE parent =0 
    UNION ALL 
    SELECT p.lvl + 1, c.id, c.catName, c.parent,c.levels,c.sort, 
     CAST(p.path + '_' + CAST(c.id AS VARCHAR) AS VARCHAR(128)) 
    FROM CategoriesMap c 
    INNER JOIN cte p ON p.id = c.parent 
) 
SELECT 
    id, 
    catName AS catName, 
    lvl, 
    levels, 
    path, 
    parent, 
    sort 
FROM cte 
ORDER BY path 

，输出是这样的形象：

寻找与价值ASP的行。 NET & CLASSIC ASP，这些是技术的最后一片叶子（孩子）>软件（父母），我想对任何给定父项的最后一个孩子进行排序（最后一位父母）。我可以有一个给定节点的多个父母（最后一个孩子）& 我所关心的是使用“排序”列排序LAST Children（leaf）。

如此基本的“经典Asp”应该在“Asp.Net”之前（最后一列是我的图片中的SORT列）。

我的查询很好，它按照预期返回结果......只有challenege是我想要使用表中的SORT列排序最后的NODE，最后一个节点可以有3或4个我想排序的子元素，全部最后一个节点之上的节点是它的父节点（它们的顺序已经是正确的）。

I want output like this.... Internet > ISP's > CableVision (1) : Verizon (2) as you can see CableVision & Verizon have Sort Value of 1 & then 2, Now lets say we have Shopping > Coupons > Macys(0) : Sears (2), same thing....I want Macys & Sears to be sorted...and its pretty obvious their parents are Shopping > Coupons.

@Richard又名cyberkiwi，将你的代码后，我的分拣分​​类表是很随意的。输出低于

Answer 1

延缓path的计算为一个电平，所以最终结果集具有可用父路径（ppath）：

;WITH cte AS (
    SELECT 0 AS lvl, id, catName, parent,levels,sort, 
     CAST('' AS VARCHAR(128)) AS ppath 
    FROM CategoriesMap WHERE parent =0 
    UNION ALL 
    SELECT p.lvl + 1, c.id, c.catName, c.parent,c.levels,c.sort, 
     CAST(p.ppath + '_' + CAST(p.id AS VARCHAR) AS VARCHAR(128)) 
    FROM CategoriesMap c 
    INNER JOIN cte p ON p.id = c.parent 
) 
SELECT 
    id, 
    catName, 
    lvl, 
    levels, 
    CAST(ppath + '_' + CAST(id AS VARCHAR) AS VARCHAR(128)) AS path, 
    parent, 
    sort 
FROM cte 
ORDER BY 
    CASE WHEN sort IS NULL 
      THEN path 
      ELSE ppath 
    END 
    , sort ; 

不确定为什么上面给出错误。这不会：

ORDER BY 
    CASE WHEN sort IS NULL 
     THEN CAST(ppath + '_' + CAST(id AS VARCHAR) AS VARCHAR(128)) 
     ELSE ppath 
    END 
    , sort ; 

Answer 2

这个SQL Fiddle应该给你你所需要的。 诀窍的确是当你将树叶与树枝混合在一起时。在我的解决方案中，叶子总是出现在树枝之前，叶子内部（即使与树枝相互混合），它们当然按sort列排序。

DDL

create table CategoriesMap(
    id int, parent int, catname varchar(20), sort int); 
insert CategoriesMap select 
    1, 0, 'Activities', null union all select 
    2, 0, 'Property', null union all select 
    3, 2, 'For rent', null union all select 
    4, 2, 'For sale', null union all select 
    12, 0, 'Technology', 3 union all select 
    15, 12, 'Hardware', null union all select 
    21, 12, 'Phones', null union all select 
    22, 15, 'Computers', null union all select 
    18, 12, 'Software', null union all select 
    19, 18, 'Asp.net', 2 union all select 
    20, 18, 'SQL', 3 union all select 
    23, 18, 'Php', 4 union all select 
    24, 18, 'Classic ASP', 1; 

查询

;WITH leaves AS (
    SELECT A.id 
     FROM CategoriesMap A 
LEFT JOIN CategoriesMap B ON A.id=B.parent 
    WHERE B.id is null 
) 
,cte AS (
    SELECT 0 AS lvl, id, catName, parent,sort, 
      CAST(id AS VARCHAR(MAX)) AS path, 
      '/'+CAST(id AS VARCHAR(MAX))+'/' AS hier 
     FROM CategoriesMap 
    WHERE parent =0 
UNION ALL 
    SELECT p.lvl + 1, c.id, c.catName, c.parent,c.sort, 
      p.path + '_' + CAST(c.id AS VARCHAR(MAX)), 
      p.hier + CAST(c.id AS VARCHAR(MAX)) + '/' 
     FROM CategoriesMap c 
     JOIN cte p ON p.id = c.parent 
) 
    SELECT c.id, 
      c.catName, 
      c.lvl, 
      --levels, 
      c.path, 
      --c.hier, 
      c.parent, 
      c.sort 
     FROM cte c 
LEFT JOIN leaves l on l.id=c.id 
    ORDER BY CASE WHEN l.id is null 
       then cast(hier as hierarchyid) 
       else cast(hier as hierarchyid).GetAncestor(1) 
       END, 
      CASE WHEN l.id is null then 0 else 1 end, 
      sort