Sql 选择父子表的映射表
Sql 选择父子表的映射表,sql,database,sql-server-2008,recursive-query,Sql,Database,Sql Server 2008,Recursive Query,我有一个带有父子关系的类别表,看起来像这样: 表名: TBL类别 列: catID catFatherID-此列与catID有关系 我需要的是用以下方式为每个类别选择它的整个家庭孩子(包括它自己): 原始表行: | catID | catFatherID | = = = = = = = = = = = = | 1 | null | | 2 | 1 | | 3 | 1 | | 4 | 2 |
我有一个带有父子关系的类别表,看起来像这样:
表名: TBL类别
列:
catID
catFatherID-此列与catID有关系
我需要的是用以下方式为每个类别选择它的整个家庭孩子(包括它自己):
原始表行:
| catID | catFatherID |
= = = = = = = = = = = =
| 1 | null |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 4 |
我想要的:| Category ID | Family Category ID |
= = = = = = = = = = = = = = = = = =
| 1 | 1 | (Yes, I want it to include itself in the return family members)
| 1 | 2 |
| 1 | 3 |
| 1 | 4 |
| 1 | 5 |
| 1 | 6 |
| 2 | 2 |
| 2 | 4 |
| 2 | 6 |
| 3 | 3 |
| 3 | 5 |
| 4 | 4 |
| 4 | 6 |
| 5 | 5 |
| 6 | 6 |
问我是否解释得不够。您应该在CTE中使用递归SQL
with families(id, parent_id) as (
select * from tblCategories where id = __initial_id__
union all
select t.* from tblCategories as t inner join families as f on t.catFatherID = f.id
)
select * from families
请参见A将是解决此问题的最佳匹配。诀窍是在执行CTE时保留根
ID
SQL语句
测试脚本
您应该保留parentId并在最终结果中选择它。在其当前形式中,这不会返回OP要求的内容。
;WITH q AS (
SELECT root = catID, catID, catFatherID
FROM tblCategories
UNION ALL
SELECT q.root, c.catID, c.catFatherID
FROM q
INNER JOIN tblCategories c ON c.catFatherID = q.catID
)
SELECT root, catID
FROM q
ORDER BY
root, catID
;WITH tblCategories (catID, catFatherID) AS (
SELECT 1, NULL
UNION ALL SELECT 2, 1
UNION ALL SELECT 3, 1
UNION ALL SELECT 4, 2
UNION ALL SELECT 5, 3
UNION ALL SELECT 6, 4
)
, q AS (
SELECT root = catID, catID, catFatherID
FROM tblCategories
UNION ALL
SELECT q.root, c.catID, c.catFatherID
FROM q
INNER JOIN tblCategories c ON c.catFatherID = q.catID
)
SELECT root, catID
FROM q
ORDER BY
root, catID
WITH n(catId, catFatherId) AS
(SELECT catId, catFatherId
FROM tblCategories
UNION ALL
SELECT n1.catId, n1.catFatherId
FROM tblCategories as n1, n
WHERE n.catId = n1.catFatherId)
SELECT * FROM n