//Linq对集合的各种查询
public static void Run()
{
List<Customers> customerlist = new List<Customers>();
customerlist.Add(new Customers() { id = 1, Name = "Jack", Custom = "Mis" });
customerlist.Add(new Customers() { id = 2, Name = "Lus", Custom = "Google" });
customerlist.Add(new Customers() { id = 3, Name = "Qiao", Custom = "Baidu" });
customerlist.Add(new Customers() { id = 4, Name = "Qiao", Custom = "Apple" });
customerlist.Add(new Customers() { id = 5, Name = "Adb", Custom = "Adobe" });
//简单的查询
var customerQuery = from query in customerlist
select query;
//带where筛选
var customerWhereQuery = from query in customerlist
where query.id == 1 && query.Name == "Lus"
select query;
//排序Ordering
var customerOrderingQuery = from query in customerlist
where query.Name == "Lus"
orderby query.id ascending
select query;
//分组Group by
var customerGroupbyQuery = from query in customerlist
group query by query.Name;
//可以使用into进一步查询
var customerGroupbyIntoQuery = from query in customerlist
group query by query.Name into queryGroup
where queryGroup.Key == "Qiao"
select queryGroup;
//联接查询 join 子句始终针对对象集合而非直接针对数据库表运行。
List<Customers> customerJoinlist = new List<Customers>();
customerJoinlist.Add(new Customers() { id = 1, Name = "Jack", Custom = "Mis" });
customerJoinlist.Add(new Customers() { id = 2, Name = "Lus", Custom = "Google" });
customerJoinlist.Add(new Customers() { id = 3, Name = "Qiao", Custom = "Baidu" });
var customerJoinQuery = from query1 in customerlist
join query2 in customerJoinlist
on query1.id equals query2.id
select new { CustomerName = query1.Name, CustomerName2 = query2.Name };
//数据源的类型参数始终为查询中的范围变量的类型。
//比如List<Customers> 类型为Customers 在循环迭代的时候类型必须可以隐式转换为Customer 有一种情况是
//这种情况下Customers类型转换为了String ..在select query.Name已经将查询目标类型定位了String类型
var customerTypeQuery = from query in customerlist
where query.Name == "Lus"
select query.Name;
//结合Lamdba对List集合筛选(s => s.Name == "Qiao")
List<Customers> listString = customerlist.Where(s => s.Name == "Qiao").ToList();
}
}
public class Customers
{
public int id { get; set; }
public string Name { get; set; }
public string Custom { get; set; }
}Linq To List 集合查询,布布扣,bubuko.com
Linq To List 集合查询
原文：http://blog.csdn.net/coolfeiweb/article/details/20395499
