LINQ to SQL 中返回单条记录

DataContext dc = new DataContext(connectionString);
        Table<Product> table = dc.GetTable<Product>();

        //价格大于5的记录条数
        int m = table.Count<Product>(p => p.UnitPrice > 5);
        //最大价格
        decimal pmax = table.Max<Product>(p => p.UnitPrice);
        //最小价格
        decimal pmin = table.Min<Product>(p => p.UnitPrice);
        //得到Id=5的产品
        Product product = table.Single<Product>(p => p.ProductID == 5);