联级查询 -- id 和 parentid 左外查询
CREATE TABLE #t1 (id VARCHAR(10),name VARCHAR(100)) CREATE TABLE #t2 ( id VARCHAR(10), parentid VARCHAR(10), name VARCHAR(100) ) INSERT INTO #t1 ( id, name ) VALUES('1','asdfad'); INSERT INTO #t1 ( id, name ) VALUES('2','送达方'); INSERT INTO #t1 ( id, name ) VALUES('3','阿飞'); INSERT INTO #t1 ( id, name ) VALUES('4','可考虑'); INSERT INTO #t1 ( id, name ) VALUES('5','发放人'); INSERT INTO #t2 ( id,parentid, name ) VALUES('1','','1ff'); INSERT INTO #t2 ( id,parentid, name ) VALUES('2','','2上等'); INSERT INTO #t2 ( id,parentid, name ) VALUES('3','','3㐇'); INSERT INTO #t2 ( id,parentid, name ) VALUES('4','','4热'); INSERT INTO #t2 ( id,parentid, name ) VALUES('5','1','5发给'); INSERT INTO #t2 ( id,parentid, name ) VALUES('6','1','6是'); INSERT INTO #t2 ( id,parentid, name ) VALUES('7','1','7的'); INSERT INTO #t2 ( id,parentid, name ) VALUES('8','1','8飞'); INSERT INTO #t2 ( id,parentid, name ) VALUES('9','','9人'); INSERT INTO #t2 ( id,parentid, name ) VALUES('0','','10E店宝'); INSERT INTO #t2 ( id,parentid, name ) VALUES('11','5','11去'); INSERT INTO #t2 ( id,parentid, name ) VALUES('12','5','124 就'); INSERT INTO #t2 ( id,parentid, name ) VALUES('13','5','13 你'); INSERT INTO #t2 ( id,parentid, name ) VALUES('14','5','14了'); GO SELECT a.id AS a_id,a.name AS a_name , b.id AS b_id,b.parentid AS b_parentid,b.name AS b_name, c.id AS b_id,c.parentid AS c_parentid,c.name AS c_name FROM #t1 AS a, #t2 AS b LEFT JOIN #t2 AS c ON b.parentid = c.id -- 子记录,使用父id 去关联父记录 WHERE a.id = b.id