Actually I can't solve by myself, about DSum function as like codes

**DSum(" [H2ExPSATotal] ","SummaryH2ExPSA") AS TotalMTD,**

So for clear my problem I post complete code, while I hope anyone maybe can help me, why my codes

DSum(" [H2ExPSATotal] ","SummaryH2ExPSA") AS TotalMTD,

not work as my expectation, I would like result the TotalMTD, add day per day, as per previus example posted, I read at other microsoft article, this problem should be put on Total : Expression, now actually I put to Total : Group By., because while I put Total : Expression , come error or conflict with codes :

[b]WHERE ((([Calc Shift 1-109].DateShift1)=[Calc Shift 2-109]![DateShift2] And ([Calc Shift 1-109].DateShift1)=[Calc Shift 3-109]![DateShift3]));

Last time I hope while I posted the complete SQL code, the reader can get complete information for my problem

But I thank very much for your response, because I can't find solver at any textbook as your give solution and tutorial, again, thank you very much

Thank