主题：代码

Dim num As Integer = 30
Dim tns() As String = {"庆前", "前列"}
For Each tn As String In tns
    Dim dt As DataTable = DataTables(tn)
    Dim q As new QueryBuilder
    q.TableName = "查询_" & tn
    Dim sql As String = ""
    For Each dc As DataCol In dt.DataCols
        If dt.Find(dc.name & " = '" & num & "'") IsNot Nothing Then
            sql &= "," & dc.name
        End If
    Next
    q.SelectString = "Select 一,二,三" & sql & " From {" & dt.Name & "}"
    q.Build
    MainTable = Tables(q.TableName)
Next

请问上述代码查询出来的行数出现了改变怎么办，我是要将含有“30”的列按照原来的顺序列到查询表中。