主题：请老师验证下学生的代码是否正确

Dim cmd As New SQLCommand
Dim dt As DataTable
Dim sCols() As String = {"日期", "销售金额", "付款渠道"}
Dim dCols() As String = {"日期", "收入", "收入渠道"}
cmd.C
cmd.CommandText = "SELECT * From {销售订单}"
dt = cmd.ExecuteReader()
For Each dr As DataRow In dt.DataRows
    Dim fdr As DataRow = DataTables("账面明细").Find("日期 = '" & dr("日期") & "'")
    If fdr IsNot Nothing Then
        If fdr("项目") = "门市收入"
            fdr("收入") = DataTables("销售订单").Compute("Sum(销售金额)", "日期 = '" & dr("日期") & "'")
        Else
            Dim nr As DataRow = DataTables("账面明细").AddNew()
            For i As Integer =0 To sCols.Length -1
                nr(dCols(i)) = dr(sCols(i))
            Next
            nr("项目") = "门市收入"
        End If
    End If
Next

最后代码改为这样，无效！