MySQL、PostgreSQL递归查询父节点(SQL语句实现)

PostgreSQL

• 表结构

id	pid	name
1	2	徒孙
2	3	徒弟
3	0	师傅

• SQL语句

WITH RECURSIVE r AS (
 
       SELECT * FROM tbl_test WHERE id= 1
     union   ALL
 
       SELECT t.* FROM tbl_test t, r WHERE t.id = r.pid
       )
SELECT * FROM r ORDER BY id

• 结果
  

MySQL

• SQL语句

SELECT * FROM ( 
                SELECT T2.id,T2.name,T2.pid
                    FROM (  
                        SELECT  
                                @r AS _id,  
                                (SELECT @r := pid FROM tbl_test WHERE id = _id) AS pid,  
                                 @l := @l + 1 AS lvl  
                        FROM  
                                (SELECT @r := 1, @l := 0) vars,  
                                tbl_test h  
                        WHERE @r != 0) T1  
                    JOIN tbl_test T2  
                    ON T1._id = T2.id 
                ) X

• 结果