public void Show() { var list = new ProductList(); var products = list.GetProductList(); Product product789 = products.FirstOrDefault(p => p.ProductID == 789); Console.WriteLine("Product 789 exists: {0}", product789 != null); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Select_Anonymous_Types_3 点标记"); //Product Info:p.ProductName, p.Category, Price = p.UnitPrice var result = products.Select(t => new { t.ProductName, t.Category, Price = t.UnitPrice }); Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("OrderByDescending_SImple_2 点标记"); //First numbers less than 6: var result = products.OrderByDescending(x => x.UnitsInStock); Print(result); }
public void Show() { var list = new ProductList(); var products = list.GetProductList(); Product product12 = ( from p in products where p.ProductID == 12 select p) .First(); Console.Write(product12.ProductID); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("GroupBy_Simple_3 点标记"); //n % 5 var result = products.GroupBy(g => g.Category).Select(g => new { Category = g.Key, products = g }); Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Select_Simple2 点标记"); //Product Names: var result = products.Select(t => new { t.ProductID, t.ProductName }); Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("OrderBy_SImple_3 点标记"); //p.ProductName var result = products.OrderBy(x => x.ProductName).ToList(); Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("ThenByDescending_SImple 点标记"); //Sorted digits: var result = products.OrderBy(x => x.Category).ThenByDescending(x => x.UnitPrice); Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Distinct_2 点标记"); //Numbers < 5: var result = products.Select(x => x.Category).Distinct(); Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Distinct_2 查询表达式"); //Numbers < 5: var result = (from t in products select t.Category).Distinct(); Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Select_Simple2 查询表达式"); //Product Names: var result = from t in products select new { t.ProductID, t.ProductName }; Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("Select_Anonymous_Types_3 查询表达式"); //Product Info: var result = from t in products select new { t.ProductName, t.Category, Price = t.UnitPrice }; Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("OrderByDescending_SImple_2 查询表达式"); //First 3 numbers: var result = from c in products orderby c.UnitsInStock descending select c; Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("OrderBy_SImple_3 查询表达式"); //First 3 numbers: var result = (from c in products orderby c.ProductName select c).ToList(); Print(result); }
public void Show() { var list = new ProductList(); var products = list.GetProductList(); var categoryCounts = from p in products group p by p.Category into g select new { Category = g.Key, ProductCount = g.Count() }; foreach (var item in categoryCounts) { Console.WriteLine(item); } }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("GroupBy_Simple_3 查询表达式"); //n % 5 var result = from w in products group w by w.Category into g select new { Category = g.Key, Products = g }; Print(result); }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var list = new ProductList(); var products = list.GetProductList(); Console.WriteLine(); Console.WriteLine("ThenByDescending_SImple 查询表达式"); //Sorted digits: var result = from c in products orderby c.Category, c.UnitPrice descending select c; Print(result); }
/// <summary> /// 点标记 /// </summary> public void Show() { var productList = new ProductList(); var soldOutProducts = productList.GetProductList(); Console.WriteLine(); Console.WriteLine("Where_Simple3 点标记"); //In-stock products that cost more than 3.00 var result = soldOutProducts.Where(t => t.UnitsInStock > 0 && t.UnitPrice > 3.0M); foreach (var item in result) { Console.WriteLine($"{ item.ProductName} is in stock and costs more than 3.00.!"); } }
/// <summary> /// 点标记 /// </summary> public void Show() { var productList = new ProductList(); var soldOutProducts = productList.GetProductList(); Console.WriteLine(); //找出products中UnitsInStock == 0 Console.WriteLine("Where_Simple2 点标记"); //找出products中UnitsInStock == 0 var result = soldOutProducts.Where(t => t.UnitsInStock == 0); foreach (var item in result) { Console.WriteLine($"{ item.ProductName} is sold out!"); } }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var productList = new ProductList(); var soldOutProducts = productList.GetProductList(); Console.WriteLine(); Console.WriteLine("Where_Simple2 查询表达式"); //找出products中UnitsInStock == 0 var result = from t in soldOutProducts where t.UnitsInStock == 0 select t; foreach (var item in result) { Console.WriteLine($"{ item.ProductName} is sold out!"); } }
/// <summary> /// 查询表达式 /// </summary> /// <param name="x"></param> public void Show(int x) { var productList = new ProductList(); var soldOutProducts = productList.GetProductList(); Console.WriteLine(); Console.WriteLine("Where_Simple3 查询表达式"); //In-stock products that cost more than 3.00 var result = from t in soldOutProducts where t.UnitsInStock > 0 && t.UnitPrice > 3.0M select t; foreach (var item in result) { Console.WriteLine($"{ item.ProductName} is in stock and costs more than 3.00.!"); } }
/// <summary> /// 点标记 /// </summary> public void Show() { var list = new ProductList(); var products = list.GetProductList(); var customers = list.GetCustomerList(); var productFirstChars = from p in products select p.ProductName[0]; var customerFirstChars = from c in customers select c.CompanyName[0]; Console.WriteLine(); Console.WriteLine("Intersect_2 点标记"); //Numbers < 5: var result = productFirstChars.Intersect(customerFirstChars).OrderBy(x => x); Print(result); }