sql - 两种不同情况下不同操作的sql表函数

Question

我想编写一个函数来查看客户在不向卖家付款的情况下花费了多少时间。我的问题是我有点困惑，因为这是已经编程的功能：

ALTER function [dbo].[bal_cli](@date date, @diff1 int,@diff2 int) returns @table1
table 
(
  solde float,
  cpt char(20)
)as

begin

insert into @table1(solde,cpt)
SELECT         SUM(a.ECRDEBIT-a.ECRCREDIT) AS solde,a.CPTCODE
  FROM            dbo.ECRITURES AS a , dbo.ECRITURES AS b
  WHERE      (a.JORID = '7' or a.JORID = '10' or a.JORID = '22' or a.JORID = '15' or a.JORID = '16' or a.JORID ='5' or a.JORID = '38' or a.JORID = '45' or a.JORID = '12' or a.JORID = '17' or a.JORID = '44' or a.JORID = '18' or a.JORID = '8' or a.JORID = '9') AND (a.ECRISMARQUE <> 'O') AND (a.CPTCODE LIKE '3421%') and 
                           ( DATEDIFF(day, a.ECRDATEEFFET, @date) >= @diff1 and  DATEDIFF(day, a.ECRDATEEFFET, @date) < @diff2) and (YEAR(a.ECRDATEEFFET) = YEAR(@date)) 

  GROUP BY a.CPTCODE

return;
end;

我的问题是我只想让 JORID 用 ECRDATEEFFET 但用 ECRLIBELLE 计算差异注释。