Asp.netMVC模型
Model负责在View和控制器之间进行数据的传递：用户输入的内容封装为Model对象，发给Controller；要显示的数据有Controller放到Model中，然后扔给View去显示。Controller不直接和View进行交互。
查询id>1的狗有如下两种方法：
lambda写法：var r=dogs.where(d=>d.id>1)
Linq写法：var r2=from d in dogs where d.id>1 select d;
Linq基本语法:以from item in items开始，items为待处理的集合，item为每一项的变量名；最后要加上select，表示结果的数据;记得select一定要放在最后
All---------Grouped
List<Product>products=GetProductList();
var productGroups=from p in products
group p by p.Category into g
where g.All(p=>p.UnitsInStock>0)
select new { Category =g.Key, Products = g };
Count-----Simple
获取列表中没有重复的元素数量
int []factors={ 2, 2, 3, 5, 5};
int unique=factors.Distinct().Count();
Console.WriteLine("There are {0} unique factors",unique);
Count---Nested
List<Customer> customers=GetCustomerList();
var orderCounts=from c in customers
select new{ c.CustomerID,OrderCount=c.Orders.Count() };
Count --------Grouped
List<Product>products=GetProductList();
var categoryCounts=from p in products
group p by p.Category into g
select new { Category=g.Key,ProductCount=g.Count() };
Sum----Grouped
List<Product>products=GetProductList();
var categories=from p in products
group p by p.Category into g
select new { Category=g.Key, TotalUnitsInstock=g.Sum(p=>p.UnitsInStock) };
ObjectDumper.Write(categories);
Min-----Projection
string[]words={"cherry","apple","blueberry"};
int shortestWord=words.Min(w=>w.Length);
Console.WriteLine("The shortest word is {0} characters long.",shortestWord);
Min-----Grouped
List<Product>products=GetProductList();
var categories=from p in products
group p by p.Category into g
select new { Category=g.Key , CheapestPrice=g.Min(p=>p.UnitPrice) };
ObjectDumper.Write(categories);
Min------Elements
List<Product>prodducts=GetProductList();
var categories=from p in products
group p by p.Category into g
let minPrice=g.Min(p=>p.UnitPrice)
select new { Category=g.Key,CheapestProducts=g.Where(p=>p.UnitPrice==minPrice) };
Max----Projection
string [ ] words={ "cherry", "apple", "blueberry" };
int longestLength=words.Max(w=>w.Length);
Console.WriteLine("The longest word is {0} characters long",longestLength);
Max-----Grouped
List<Product>products=GetProductList();
var categories=from p in products
group p by p.Category into g
select new {Category=g.Key,MostExpensivePrice=g.Max(p=>p.UnitPrice) };
Max------Elements
List<Product>products=GetProductList();
var categories=from p in products
group p by p.Category into g
let maxPrice=g.Max(p=>p.UnitPrice)
select new { Category=g.Key, MostExpensiveProducts=g.Where(p=>p.UnitPrice==maxPrice) };
ObjectDumper.Write(categories,1);
Average ---Projection
string[] words={"cherry", "apple", "blueberry"};
double averageLength=words.Average(w=>w.Length);
Console.WriteLine("The average word length is {0} characters.",averageLength);
Average----Grouped
List<Product>products=GetProductList();
var categories=from p in products
group p by p.Category into g
select new {Category=g.Key, AveragePrice=g.Average(p=>p.UnitPrice) };
Aggregate----Simple
这个例子是数组中所有的元素相乘，求出最终的积
double[] doubles={1.7, 2.3, 1.9, 4.1, 2.9};
double product=doubles.Aggregate((runningProduct,nextFactor)=>runningProduct*nextFactor);
Console.WriteLine("Total product of all numbers:{0}",product);
Concat----1
求两个集合的合集
int[] numbersA={0,2,4,5,6,8,9};
int[] numbersB={1,3,5,7,8};
var allNumbers=numbersA.Concat(numbersB);
Console.WriteLine("All numbers from both arrays:");
foreach(var n in allNumbers){
Console.WriteLine(n);
}
Concat---2
List<Customer>customers=GetCustomerList();
List<Product>products=GetProductList();
var customerNames=from c in customers
select c.CompanyName;
var productNames=from p in products
select p.ProductName;
var allNames=customerNames.Concat(productNames);
Console.WriteLine("Customer and product names:");
foreach(var n in allNames){
Console.WriteLine(n);
}
SequenceEqual--1
var wordA=new string[]{ "cherry", "apple", "blueberry"};
var wordB=new string[]{"cherry", "apple", "blueberry"};
bool match=wordsA.SequenceEqual(wordsB);
Console.WriteLine("The sequences match: {0} ",match);
SequenceEqual--2
var wordsA=new string[]{"cherry", "apple", "blueberry"};
var wordsB=new string[]{"apple","blueberry","cherry"};
bool match=wordsA.SequenceEqual(wordsB);
Console.WriteLine("The sequences match:{0}", match);
List集合Group by 查询
var groupList=chRCheckConfirmList.GroupBy(x=>new {x.CompanyId, x.Type, x.ChRCheckItemConfigId}).select(group=>new { Keys=group.Key, TotalScore=group.Sum(p=>p.Score)})
