select SUBSTRING_INDEX('a,b,c,d',',',1) from xxx union all select SUBSTRING_INDEX(SUBSTRING_INDEX('a,b,c,d',',',2),',',-1) from xxx union all select SUBSTRING_INDEX(SUBSTRING_INDEX('a,b,c,d',',',4),',',-1) from xxx union all select SUBSTRING_INDEX('a,b,c,d',',',-1) from xxx
union all
select SUBSTRING_INDEX(SUBSTRING_INDEX('a,b,c,d',',',2),',',-1) from xxx
union all
select SUBSTRING_INDEX(SUBSTRING_INDEX('a,b,c,d',',',4),',',-1) from xxx
union all
select SUBSTRING_INDEX('a,b,c,d',',',-1) from xxx
用SUBSTRING_INDEX一条条的拆吧,1楼的办法。