TSimpleDataSet的问题 ,在线待 (100分)

Delphi6里的TSQLClientDataSet有Option和UpdateMode属性,但在
Delphi7里的TSimpleDataSet去没有,所以在commandtext:
select A.*,B.MC002 from INVMB AS A LEFT JOIN INVMC AS B ON B.MC001=A.MB001
更新时总是出错,说找不到MC002,在Delphi6里设UpdateMode为upWhereChange可解决此问题,
declare @P1 int
set @P1=2
exec sp_prepexec @P1 output, N'@P1 char(10),@P2 char(10)', N'update "INVMB" set
"MB003" = @P1
where
"MB003" = @P2
', 'BBB
请问
Delphi7里的TSimpleDataSet如何做,Delphi7里的TSimpleDataSet的更新语句会是:
declare @P1 int
set @P1=NULL
exec sp_prepexec @P1 output, N'@P1 char(10),@P2 char(10),@P3 char(10),@P4 char(10)', N'update "INVMB" set
"MB003" = @P1
where
"MB001" = @P2 and
"MB002" = @P3 and
"MB003" = @P4 and
"MC002" is null
', 'b

,所以出错