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);
}