Mysql将记录分成两行

Question

我使用以下查询从表中选择记录：

SELECT (@curRank := IF(@prevVal=stu_code, @curRank, @curRank+1)) AS 'index_no', 'ac01' as accNo, ""  as debitamount, amount as creditamount,   
@prevVal:=stu_code 
FROM payment p,(SELECT @curRank :=0, @prevVal:=null) r 

SELECT (@curRank := IF(@prevVal=stu_code, @curRank, @curRank+1)) AS 'index_no', 'ac02' as accNo, amount  as debitamount, "" as creditamount,   
@prevVal:=stu_code 
FROM payment p,(SELECT @curRank :=0, @prevVal:=null) r 

如您所见，唯一的区别是查询是accNo，debitamount和creditamount。但我不能在不同的查询中选择，这是不准确的。那么如何将一条记录拆分为两个具有相同index_no的行，但不同的accNo，debitamount和creditamount？

我想将一条记录分成两行更准确。

感谢。