Get Max Len of each column in dataset

I have the follwoin to count the number of completed rows in an excel spreadsheet:

Code:

---

Dim objDataAdapter3 As New OleDbDataAdapter()
                    objDataAdapter3.SelectCommand = cmdExcel3
                    Dim objDataSet3 As New DataSet
                    objDataAdapter3.Fill(objDataSet3)
                    Dim i As Integer = 0
                    While i <= objDataSet3.Tables(0).Rows.Count - 1
                        If objDataSet3.Tables(0).Rows(i)("CLI").ToString().Trim() = String.Empty Then
                            objDataSet3.Tables(0).Rows.RemoveAt(i)
                        Else
                            i += 1
                        End If
                    End While

---

I would like to return at the same point the largest LEN of each column so that i can validate wether or not they have entered something that is too large for me sql database.

Any ideas?