Network_buildingEntities context = new Network_buildingEntities();
            var emp =
            from em in context.Employees
                    select em;
            var sk =
                from skl in context.Skills
                 where skl.Router_setup == "+"
                 select skl;
            Bids Bid = new Bids();
            Bid.BidID = 3;
            Bid.BuildID = 2;
            Bid.TechID = 3; //сюда подставить новое значение
            Bid.Status_of_operations = "InProgress";
            Bid.Dates = DateTime.Today;
            context.Bids.Add(Bid);
            context.SaveChanges();
            this.bidsTableAdapter.Fill(this.network_buildingDataSet.Bids);

private void button3_Click(object sender, EventArgs e)
        {
            Network_buildingEntities context = new Network_buildingEntities();
            foreach (var em in context.Employees)
            {
                foreach (var sk in context.Skills)
                {
                    if (em.TechID == sk.SkilliD && sk.Router_setup == "+")
                    {
                        Bids Bid = new Bids();
                        Bid.BidID = 3;
                        Bid.BuildID = 2;
                        Bid.TechID = em.TechID;
                        Bid.Status_of_operations = "InProgress";
                        Bid.Dates = DateTime.Today;
                        context.Bids.Add(Bid);
                    }
                }
            }         
            context.SaveChanges();
            this.bidsTableAdapter.Fill(this.network_buildingDataSet.Bids);
        }