主题：请教在窗口中如何用In关键字

im dt2 As DataTable
        Dim dr2 As DataRow
        cmd.CommandText = "select gID from {gradeInfo} where gradeName = '" & e.Form.Controls("cbcgInfo").value.trim() & "'"
        dt = cmd.ExecuteReader()
        dr = dt.DataRows(0)
        cmd.CommandText = "select cID from {classInfo} where gID = " & dr("gID")
        dt2 = cmd.ExecuteReader()
        'dr2 = dt2.DataCols
        MessageBox.Show(dt2.DataCols("cID").Tostring)
        Tables("档案信息_studentInfo").Filter = " 班级 in  条件

怎么用IN关键字，如何根据查询的cID的值作条件