LINQ Sorguları

var result = from student in students
             where student.Age > 20
             select student.Name;

var result = students
    .Where(s => s.Age > 20)
    .Select(s => s.Name);

var adults = students.Where(s => s.Age >= 18);

var strings = objects.OfType<string>();

var uniqueAges = students.Select(s => s.Age).Distinct();

var names = students.Select(s => s.Name);

// Anonim tip
var studentInfo = students.Select(s => new { s.Name, s.Age });

var allCourses = students.SelectMany(s => s.Courses);

var sorted = students.OrderBy(s => s.Age);

var sorted = students.OrderByDescending(s => s.Age);

var sorted = students
    .OrderBy(s => s.Department)
    .ThenBy(s => s.Name);

var grouped = students.GroupBy(s => s.Department);

foreach (var group in grouped)
{
    Console.WriteLine($"Department: {group.Key}");
    foreach (var student in group)
    {
        Console.WriteLine(student.Name);
    }
}

var result = from student in students
             join course in courses on student.CourseId equals course.Id
             select new { student.Name, course.Title };

// Method Syntax
var result = students.Join(
    courses,
    s => s.CourseId,
    c => c.Id,
    (s, c) => new { s.Name, c.Title }
);

var result = from department in departments
             join student in students on department.Id equals student.DepartmentId into studentGroup
             select new { department.Name, Students = studentGroup };

var combined = list1.Union(list2);

var common = list1.Intersect(list2);

var difference = list1.Except(list2);

int count = students.Count();
int adultCount = students.Count(s => s.Age >= 18);

int totalAge = students.Sum(s => s.Age);

double avgAge = students.Average(s => s.Age);

int minAge = students.Min(s => s.Age);
int maxAge = students.Max(s => s.Age);

string names = students.Aggregate("", (acc, s) => acc + s.Name + ", ");

var skipped = students.Skip(10);

var first10 = students.Take(10);

var result = students.SkipWhile(s => s.Age < 20);
var result = students.TakeWhile(s => s.Age < 25);

bool hasAdults = students.Any(s => s.Age >= 18);

bool allAdults = students.All(s => s.Age >= 18);

bool contains = students.Contains(student);

var first = students.First();
var first = students.FirstOrDefault();
var first = students.First(s => s.Age > 20);

var last = students.Last();
var last = students.LastOrDefault();

var single = students.Single(s => s.Id == 1);
var single = students.SingleOrDefault(s => s.Id == 1);

var element = students.ElementAt(5);

// (parametreler) => ifade
(x) => x * 2
(x, y) => x + y
() => DateTime.Now

var adults = students.Where(s => s.Age >= 18);

var result = students.Where(s => 
    s.Age >= 18 && 
    s.Department == "Engineering" && 
    s.GPA > 3.0
);

var result = students.Where(s => s.Address != null && s.Address.City == "Istanbul");

var result = students.Where(s => s.Name.StartsWith("A"));
var result = students.Where(s => s.Email.Contains("@gmail.com"));

var result = students.Where(s => s.GPA > 3.5 && s.GPA <= 4.0);

var result = students.Where(s => s.EnrollmentDate.Year == 2023);

// Tek özellik
var names = students.Select(s => s.Name);

// Anonim tip
var info = students.Select(s => new { s.Name, s.Age });

// Hesaplanmış değer
var ages = students.Select(s => DateTime.Now.Year - s.BirthYear);

var grouped = students.GroupBy(s => s.Department);

var grouped = students
    .GroupBy(s => s.Department)
    .Select(g => new 
    { 
        Department = g.Key, 
        Count = g.Count(), 
        AvgAge = g.Average(s => s.Age) 
    });

var sorted = students.OrderBy(s => s.Age).ThenBy(s => s.Name);

var query = students.Where(s => s.Age > 20); // Henüz çalışmaz
var result = query.ToList(); // Burada çalışır

var result = students.Where(s => s.Age > 20).ToList(); // Hemen çalışır

// LINQ to Objects (Bellek içi)
var students = new List<Student>();
var result = students.Where(s => s.Age > 20).ToList();

// LINQ to SQL (Veritabanı)
var result = dbContext.Students.Where(s => s.Age > 20).ToList();