sql server 2005 with如何实现递归

Posted 2023-04-11

用SQL SERVER做递归子节点时，从网上发现很多《SQL2005使用with关键字解决递归父子关系》这样的文章，我从SQL帮助找到WITH用法，发现有点难理解，麻烦大家讲解下with的用法，下面是copy下来的语法：[ WITH <common_table_expression> [ ,...n ] ] <common_table_expression>::= expression_name [ ( column_name [ ,...n ] ) ] AS ( CTE_query_definition )

参考技术A 比如有张表,结构如下:Example(ID int,ParentID int)取其某个ID为父节点的树结构的SQL如下：WITH Example_Table(ID,ParentID)AS( --取根节点放入临时表 SELECT ID,ParentID FROM Example WHERE ID = @ID --根据已取到的数据递归取其字节点的数据 UNION ALL SELECT ID,ParentID FROM Example A INNER JOIN Example_Table B ON A.ParentID = B.ID)SELECT * FROM Example_Table 参考技术B 。。。不会

SQL SERVER 之 WITH AS 递归

WITH    Category_Tree
          AS ( SELECT   Code
               FROM     SubjectDB.Supplier.SupplierCategory
               WHERE    Code LIKE \'0101%\'
             )

SELECT  *
FROM    SubjectDB.Supplier.SupplierCategory
WHERE   Code IN ( SELECT    *
                      FROM      Category_Tree ) 

查询结果：