主题：请问错误:不存在名称为"sqlcmd"的datatable?

Dim sqltable As DataTable = DataTables("sqltable")
Dim dlg As New OpenFileDialog
dlg.Filter = "Accese文件|*.mdb"
dlg.MultiSelect = True

If dlg.ShowDialog = DialogResult.Ok Then
    For Each File As String In dlg.FileNames
        '遍历所选的Access文件名
        If Connections.Contains("newsql") Then     '判断是否存在某一数据源
            Connections.Delete("newsql")   '如果有就删除
        End If
        Connections.Add("newsql","Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & file & ";Persist Security Info=False")   '把选择的Access文件新建一个数据源      '
        Dim  conn As Connection = Connections("newsql")    '定义数据源
        Dim lst As List(Of String)
        lst = conn.GetTableNames  '所有表
        For Each nm As String In lst
            Dim cmd As new SQLCommand
            cmd.ConnectionName = "newsql"
            cmd.CommandText = "select * from {" & nm & "} where 1=2"
            Dim tb As DataTable = cmd.ExecuteReader
            Dim mColCount As Integer = tb.dataCols.count()
            Dim dr As DataRow = sqltable.addnew()
            dr("Fullmdbname") = file
            dr("mdbname") = FileSys.GetName(file)
            dr("cnname") = conn.name
            dr("tablename") = nm
            dr("ColCount") = mColCount
        Next
    Next
End If