How to get databse value in combobox of datagridview.

I have 10 columns in datagridview out of which last 3 columns(caste,prof,degree) are combobox. My task is if database have value for these 3 fields,it should display in combobox of grid else empty combobox should be added for user to select value.Code to add combobox column is below.Can any1 please help me.

Dim con As OdbcConnection = New OdbcConnection
        sql = "Select Description from Category where Catgry = 1"
        con.ConnectionString = connstring
        If con.State = ConnectionState.Open Then con.Close()
        con.Open()
        Dim da As OdbcDataAdapter = New OdbcDataAdapter(sql, con)
        da.Fill(ds, "Caste")
 
        With col_Caste
            .Name = "Caste"
            .HeaderText = "Caste"
            .DataSource = ds.Tables("Caste")
            .DisplayMember = "Description"
            .ReadOnly = False
        End With
 
        dgvUserDetails.Columns.Add(col_Caste)