Dim s As String = e.Form.Controls("年月").text '选择月份
For Each v As String() In DataTables("表A1").GetValues("年份|月份", "月份='" & s & "'")
Dim drx As DataRow = DataTables("表B1").Find("月份 = '" & s & "'")
If drx IsNot Nothing Then '如果找到的话
Else
Dim dr As DataRow = DataTables("表B1").AddNew()
dr("年份") = v(0)
dr("月份") = v(1)
End If