自參照表

Question

我有一個自引用表，像這樣的內容：

Self-referencing parent table 
ID ParentID Name 
--------------------- 
1    John 
2 1   Mike 
3 2   Erin 
4 1   Janie 
5    Eric 
6 5   Peter 

樹的層次結構應該是這樣的

• 約翰
  • 邁克
    • Erin
  • 珍妮
• 埃裏克
  • 彼得

和存儲父表的，看起來像這樣的樹葉子表：

ID Sales 
3 100 
3 100 
4 200 
4 200 
6 300 
6 300 
6 300 

我試圖將總和從葉節點上傳到層次結構，因此它將返回爲。 。

ID Name Sum 
1 John 800 
2 Mike 200 
3 Erin 200 
4 Janie 400 
5 Eric 900 
6 Peter 900 

任何想法如何在SQL 2008中實現這一點？提前致謝。

Answer 1

編輯所有聚集移出CTE的

WITH 
    tree AS 
(
    SELECT 
    id    AS root_id, 
    name    AS root_name, 
    id    AS leaf_id 
    FROM 
    yourTreeTable 

    UNION ALL 

    SELECT 
    tree.root_id  AS root_id, 
    tree.name   AS root_name, 
    yourTreeTable.id AS leaf_id 
    FROM 
    tree 
    INNER JOIN 
    yourTreeTable 
     ON tree.leaf_id = yourTreeTable.ParentID 
) 
SELECT 
    tree.root_id, 
    tree.root_name, 
    COALESCE(SUM(yourScoresTable.score), 0) AS total 
FROM 
    tree 
LEFT JOIN 
    yourScoresTable 
    ON yourScoresTable.ID = tree.leafID 
GROUP BY 
    tree.root_id, 
    tree.root_name 

Answer 2

這就是：

讓我們supose這個模式：

​create table #parent (
ID int, 
ParentID int, 
Name varchar(50)); 

create table #child (
ID int, 
Sales int); 

查詢是自我解釋說：

WITH 
    tree AS 
(
    SELECT 
    id as id_parent, 
    id as id 
    FROM 
    #parent 
    UNION ALL 
    SELECT 
    tree.id_parent as id_parent, 
    #parent.id AS id 
    FROM 
    tree 
    INNER JOIN 
    #parent  
     ON tree.id = #parent.ParentID 
) 
SELECT 
    #parent.id, 
    #parent.name, 
    COALESCE(SUM(#child.Sales), 0) AS total 
FROM 
    #parent 
LEFT JOIN 
    tree 
    ON #parent.ID = tree.id_parent 
LEFT JOIN 
    #child on tree.id = #child.id 
GROUP BY 
    #parent.id, 
    #parent.name 

CTE返回每個員工（#parent）的「葉子」列表，然後查詢爲此「葉子」的所有銷售額進行彙總。 You can test it running。

EDITED

查詢是固定的。