在SQL Server中創建層次結構

Question

我有以下格式的數據。

表1

e_id e_name e_type 
------------------------- 
1  CBC  2 
2  ABC  3 
3  N2  1 
4  CBC1 3 
5  ABC1 3 
6  N1  1 

表2

N_ID N_Name 
--------------- 
3  N2 
6  N1 

表3

N_ID E_ID 
------------ 
3  1 
3  2 
3  3 
6  4 
6  5 
6  6 

我想建立一個層次結構如下。

e_id e_name  e_type n_id 
------------------------------------ 
6  N1   1  6 
4  - ABC1  3  6 
5  - CBC1  3  6 
3  N2   1  3 
4  - ABC  3  3 
5  - CBC  2  3 

按節點順序（升序），子節點（升序）。

我試着做一些與此類似，

SELECT u.e_id, 
CASE WHEN e_TYPE_ID = 1 THEN u.e_name ELSE ' - ' + u.e_name END e_name, 
e_TYPE_ID, su.n_ID 
FROM table1 u 
INNER JOIN table3 su on u.e_id = su.e_id 
WHERE EXISTS (SELECT N_ID FROM table2 WHERE N_ID = CASE WHEN u.e_TYPE_ID = 1 THEN u.e_id ELSE n_ID END) 
ORDER BY e_TYPE_ID, u.e_name,n_id 

但我不能得到正確的次序，有沒有更好的方式來做到這一點？

Answer 1

如果您使用SQL Server 2008（或2008 R2），我會建議使用層次ID，如Model Your Data Hierarchies With SQL Server 2008所示。

Answer 2

我要把你在正確的道路上，你將需要一個CTE（公共表表達式）來完成這個任務：你爲什麼需要這些麪條

;with EH as 
(
select 1 level, * from Table1 t1 where e_type = 1 
union all 
select level+1, * from EH 
join Table3 t3 on eh.e_id = t3.e_id 
join Table3 t32 on t3.n_id = t32.n_id and t3.e_id 

--FUUUUUUUUUUUUUUUUUUUUU!!!!!!!!!!!!!!1111 

[更新]

無論如何表？你爲什麼不把所有東西放在一張或兩張桌子上？

Answer 3

用途：

WITH summary AS (
    SELECT a.e_id, 
     a.e_name, 
     a.e_type, 
     b.n_id, 
     CASE WHEN e_type = 1 THEN e_type ELSE 2 END AS rank 
    FROM TABLE1 a 
    JOIN TABLE3 b ON b.e_id = a.e_id) 
    SELECT s.e_id, 
      CASE 
      WHEN s.rank > 1 THEN ' - '+ s.e_name 
      ELSE s.e_name 
      END AS e_name, 
      s.e_type, 
      s.n_id 
    FROM summary s 
ORDER BY s.n_id DESC, s.rank, s.e_name 

我使用測試：

WITH table2 AS (
    SELECT 3 AS n_id, 'N2' AS n_name 
    UNION ALL 
    SELECT 6, 'N1'), 
    table1 AS (
    SELECT 1 AS e_id, 'CBC' AS e_name, 2 AS e_type 
    UNION ALL 
    SELECT 2, 'ABC', 3 
    UNION ALL 
    SELECT 3, 'N2', 1 
    UNION ALL 
    SELECT 4, 'CBC1', 3 
    UNION ALL 
    SELECT 5, 'ABC1', 3 
    UNION ALL 
    SELECT 6, 'N1', 1), 
    table3 AS (
    SELECT 3 AS n_id, 1 AS e_id 
    UNION ALL 
    SELECT 3, 2 
    UNION ALL 
    SELECT 3, 3 
    UNION ALL 
    SELECT 6, 4 
    UNION ALL 
    SELECT 6, 5 
    UNION ALL 
    SELECT 6, 6), 
    summary AS (
    SELECT a.e_id, 
      a.e_name, 
      a.e_type, 
      b.n_id, 
      CASE WHEN e_type = 1 THEN e_type ELSE 2 END AS rank 
    FROM TABLE1 a 
    JOIN TABLE3 b ON b.e_id = a.e_id) 
    SELECT s.e_id, 
     CASE 
      WHEN s.rank > 1 THEN ' - '+ s.e_name 
      ELSE s.e_name 
     END AS e_name, 
     s.e_type, 
     s.n_id 
    FROM summary s 
ORDER BY s.n_id DESC, s.rank, s.e_name