static void Main(string[] args)
{
var books = new BookRepository().GetBooks();
var cheapBooks = books.Where(b => b.Price < 10);
// LINQ Query Operator
var cheaperBooks =
from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// LINQ Methods can be chained
var orderedByTitle = books
.OrderBy(b => b.Title)
.Select(b => b.Title);
foreach (var b in orderedByTitle)
{
Console.WriteLine(b);
}
// Other Examples
var result1 = books.Single(book => book.Title == "A");
var result2 = books.SingleOrDefault(b => b.Title == "A");
var result3 = books.FirstOrDefault(b => b.Title == "A");
var result4 = books.LastOrDefault(b => b.Title == "A");
var result5 = books.Skip(2).Take(3);
var result6 = books.Count();
var result7 = books.Max(b => b.Price);
var result8 = books.Sum(b => b.Price);
var result9 = books.Average(b => b.Price);
Console.ReadLine();
}
static void Main(string[] args)
{
var people = new List <Person>()
{
new Person()
{
Name = "Anastasia", Job = "Developer"
},
new Person()
{
Name = "Dzmitry", Job = "Developer"
},
new Person()
{
Name = "Peter", Job = "Bookeeper"
},
new Person()
{
Name = "Josh", Job = "Cook"
},
new Person()
{
Name = "Aaron", Job = "Cook"
},
new Person()
{
Name = "Anastasia", Job = "Server"
},
};
var anastasias = from p in people
where p.Job == "Developer"
select p;
foreach (var anastasia in anastasias)
{
Console.WriteLine(anastasia.Job);
Console.WriteLine(anastasia.Name);
}
var books = new BookRepository().GetBooks();
//With select you can select by property
var cheapBooksTitles = books
.Where(b => b.Price < 10)
.Where(b => b.Price < 10)
.Select(b => b.Title);
// Linq query Operator like a SQL
var cheaperBooks = from b in books
where b.Price < 10
orderby b.Title
select b.Title;
// Returning Single Book or Operator || SingleOrDefault will return null as a value
var singleBook = books.SingleOrDefault(b => b.Title == "ASP.NET MVC");
Console.WriteLine(singleBook.Price);
// can find the first value that matche the query || FirstOrDefalult
Console.WriteLine(books.First(b => b.Title == "C# Advanced Topics").Title);
// Last || LastOrDefault
Console.WriteLine(books.Last(b => b.Title == "C# Advanced Topics").Title);
// Skiping the data
Console.WriteLine(books.Skip(2).Take(3).Select(b => b.Title));
// Aggregators
Console.WriteLine("Aggregators");
Console.WriteLine(books.Count());
//Max Price
Console.WriteLine(books.Max(x => x.Price));
// Cheppest Price
Console.WriteLine(books.Min(x => x.Price));
// Sum
Console.WriteLine(books.Sum(b => b.Price));
// Aggregate fuinctions
var list = new List <int>()
{
13, 18, 25, 12, 16
};
list.Aggregate((a, b) => a + b);
// Get Avarage
var avgPrice = books.Average(b => b.Price);
Console.WriteLine("The avarage book price is {0} ", avgPrice);
foreach (var s in books.Skip(2).Take(3).Select(b => b.Title))
{
Console.WriteLine("Skipped Book {0} ", s);
}
foreach (var cheapBooksTitle in cheapBooksTitles)
{
Console.WriteLine(cheapBooksTitle);
}
foreach (var book in books.OrderBy(b => b.Title).Where(b => b.Price < 10))
{
Console.WriteLine(book.Title);
Console.WriteLine(book.Price);
}
}