[Table]
public class Документ{}
[Table]
public class ДетальнаЧасть{}
 

DataGridView.DataSource = bindingsource1;
bindingsource1.DataSource = DataContext.ДетальнаЧастьs

db.TableDtls.DeleteOnSubmit(item);

        internal void CheckSchetDtl()
        {

            foreach (DSPlatSchetDtlRow row in SchetDtl.Rows)
            {
                switch (row.RowState)
                {
                    case DataRowState.Added:
                    case DataRowState.Modified:
                        row.ClearErrors();

                        if (row.Isrsh_numNull())
                            row.SetColumnError(SchetDtl.numColumn, "Нет номера счёта!");

partial void UpdateOrder(Order instance)
{
    if ((instance.ShipVia ==  3 ) && (instance.Freight <  10 ))
    {
        string ErrorMessage = "Federal Shipping " +
            "does not deliver for less than 10. " +
            "You must use a different shipper.";
        throw new System.Exception(ErrorMessage);
    }
}