The types of LINQ are mentioned below in brief.
? LINQ to Objects
? LINQ to XML(XLINQ)
? LINQ to DataSet
? LINQ to SQL (DLINQ)
? LINQ to Entities
Apart from the above, there is also a LINQ type named PLINQ which is Microsoft’s parallel LINQ.
var list = (from e in employees
join d in departments on e.DepartmentId equals d.DepartmentId
select new
{
EmployeeName = e.EmployeeName,
DepartmentName = d.Name,
});
foreach(var e in list)
{
Console.WriteLine("Employee name={0},Department Name={1}",e.EmployeeName,e.DepartmentName);
}
List<string> phrases = new List<string> { "an apple a day", "the quick brown fox" };
var query = from phrase in phrases
from word in phrase.Split(‘ ‘)
select word;
foreach(var s in query)
{
Console.WriteLine(s);
}
Console.ReadLine();
static void Main(string[] args)
{
int[] num = { -20, 12, 6, 10, 0, -3, 1 };
var posNum = from n in num
orderby n
select n;
Console.WriteLine("Values in ascending order: ");
foreach(int i in posNum)
{
Console.WriteLine(i);
}
var posNumsDesc = from n in num
orderby n descending
select n;
Console.WriteLine("\nValues in descending order: ");
foreach(int i in posNumsDesc)
{
Console.WriteLine(i);
}
Console.ReadLine();
}
static void Main(string[] args)
{
List<int> numbers = new List<int>() { 35, 44, 200, 84, 3987, 4, 199, 329, 446, 208 };
IEnumerable<IGrouping<int, int>> query = from num in numbers
group num by num % 2;
foreach(var group in query)
{
Console.WriteLine(group.Key == 0 ? "\nEven numbers: " : "\nOdd numbers: ");
foreach(var i in group)
{
Console.WriteLine(i);
}
}
Console.ReadLine();
}
class Program
{
static void Main(string[] args)
{
Plant[] plants = new Plant[]
{
new CarnivorousPlant
{
Name="Venus Fly Trap",
TrapType="Snap Trap"
},
new CarnivorousPlant
{
Name="Pitcher Plant",
TrapType="Pitfall Trap"
},
new CarnivorousPlant
{
Name="Sundew",
TrapType="Flaypaper Trap"
},
new CarnivorousPlant
{
Name="WaterWheel Plant",
TrapType="Snap Trap"
}
};
var query = from CarnivorousPlant cPlant in plants
where cPlant.TrapType == "Snap Trap"
select cPlant;
foreach(var q in query)
{
Console.WriteLine("Name={0},Trap Type={1}", q.Name, q.TrapType);
}
Console.WriteLine("\nPress any key to continue");
Console.ReadLine();
}
}
class Plant
{
public string Name { get; set; }
}
class CarnivorousPlant:Plant
{
public string TrapType { get; set; }
}
class Program
{
static void Main(string[] args)
{
Pet[] cats = GetCats();
Pet[] dogs = GetDogs();
IEnumerable<string> query = cats.Select(cat => cat.Name).Concat(dogs.Select(dog => dog.Name));
foreach(var e in query)
{
Console.WriteLine("Name={0}", e);
}
Console.WriteLine("\nPress any key to continue");
Console.ReadLine();
}
static Pet[] GetCats()
{
Pet[] cats = {new Pet { Name="Barley",Age=8},
new Pet{Name="Boots",Age=4},
new Pet{Name="Whiskers",Age=1}};
return cats;
}
static Pet[] GetDogs()
{
Pet[] dogs =
{
new Pet{Name="Bounder",Age=3},
new Pet{Name="Snoopy",Age=14},
new Pet{Name="Fido",Age=9}
};
return dogs;
}
}
class Pet
{
public string Name { get; set; }
public int Age { get; set; }
}
原文：http://www.cnblogs.com/Fred1987/p/6363857.html