Hy, I need a help on this, I have a datagridview with several columns, but what I´m trying to do is sum km2 column based on date. I´m using the following code:

Code:
    Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Me.CadastroSeqTableAdapter.Fill(Me.Db01DataSet.CadastroSeq)

	Dim con As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\db01.mdb")
        Dim ds As New DataSet
        Dim da As OleDb.OleDbDataAdapter
        Dim sql As String

        sql = "SELECT Data, Sum(Km2_FF) FROM CadastroSeq GROUP BY Data"
        da = New OleDbDataAdapter(sql, con)

        Dim dt As New DataTable("CadastroSeq")

        da.Fill(dt)
        CadastroSeqDataGridView.DataSource = dt

    End Sub
The query is grouping by DATE (data), this OK, but the km2_FF values not, is not showing anything. Do you guys have a different solution or to fix this one?
To be more clearer, this datagridview has different values of km2_FF for the same date, I want to display the total of km2_FF for each day.
Thanks.