很多時候,我們在同一個表裏存儲具有相同屬性,但有層次關係的數據,比下我做項目中的黨機關的級別(黨委--總支--支部--小組)或省市的級聯。
這個時候,就要用到Sql server的WITH All_Branch AS 子句裏,它利用了臨時表來進行操作的。不多講,看語句
WITH All_Branch AS(SELECT id,name FROM party_category WHERE id= " + branchID + " UNION ALL SELECT a.id,a.name FROM party_category AS a,All_Branch AS b WHERE a.parent_id = b.id ) SELECT * FROM All_Branch