mysql 的列转行

mysql 的列转行想找个函数，但是没有找到

目前是通过有条件的笛卡尔积完成的。

DROP IF EXISTS TABLE pyb_tmp_160315_2


CREATE TABLE pyb_tmp_160315_2 (
 id INT,
 NAME VARCHAR(200)


) ;


INSERT INTO pyb_tmp_160315_2
VALUES(1,'a'),(2,'a,b'),(3,'a,b,c'),(4,'b'),(5,'d,e')
;




SELECT *
FROM pyb_tmp_160315_2
WHERE 1=1
;





SET @max_num:=0;


SELECT  
      t0.id,      
      SUBSTRING_INDEX(SUBSTRING_INDEX( REPLACE(REPLACE(t0.name,'[',''),']','') ,',',t1.row_name_num),',',-1) AS name2
FROM (
SELECT LENGTH(wu.name)-LENGTH( REPLACE(wu.name,',',''))+1 AS name_num,
      wu.*
FROM pyb_tmp_160315_2 wu
WHERE 1=1
     ) t0
JOIN 
(     SELECT t0.max_num_1 AS row_name_num
FROM (
SELECT @max_num:=@max_num+1 max_num_1
  FROM pyb_tmp_160315_2 
    ) t0
WHERE 1=1
AND max_num_1 <= ( SELECT MAX(LENGTH(wui.name)-LENGTH( REPLACE(wui.name,',',''))+1) AS row_department_num FROM pyb_tmp_160315_2 wui )
) t1
ON t1.row_name_num<=t0.name_num
;