Dim drs as List(of datarow) = datatables("本表").Select("合同编号 = '" & e.datarow(“合同编号") & "'")
If drs(0)("_Identify") = e.Datarow("_Identify") Then
e.DataRow("未付本金")=datatables("合同").Compute("Sum(本金)", "[合同编号] = '" & e.datarow("合同编号") & "'")
End if