static void Main(string[] args)
{
using (var ctx = new DvdrentalContext())
{
string[] first = new string[] { "hello", "hi", "good evening", "good day", "good morning", "goodbye" };
string[] second = new string[] { "whatsup", "how are you", "hello", "bye", "hi" };
var res = first.Union(second);
Console.ReadKey();
}
}
public void Exercise()
{
var ctx = new DvdrentalContext();
// 1. Which actors have the first name ‘Scarlett’ => 2
//var restult = ctx.Actor.Where(x => x.FirstName == "Scarlett").ToList();
// 2. How many distinct actors last names are there? => 122
//var restult = ctx.Actor.Select(x => x.LastName).Distinct().ToList();
//var restult = ctx.Actor.GroupBy(x => x.LastName)
// .Select(x => x.First())
// .ToList().Count;
// 3. Which last names are not repeated?
var restult = ctx.Actor.Select(x => x.LastName).ToList();
var arrayOfAllNames = new List <string>();
var arrayOfDuplicateNames = new List <string>();
var arrayOfSingleNames = new List <string>();
foreach (var item in restult)
{
if (!arrayOfAllNames.Contains(item))
{
arrayOfAllNames.Add(item);
}
else if (!arrayOfDuplicateNames.Contains(item))
{
arrayOfDuplicateNames.Add(item);
}
}
foreach (var allName in arrayOfAllNames)
{
if (!arrayOfDuplicateNames.Contains(allName))
{
arrayOfSingleNames.Add(allName);
}
}
var filteredList = ctx.Actor.GroupBy(x => x.LastName)
.Where(x => x.Count() == 1)
.OrderBy(x => x.Key)
.Select(x => x.First());
// 4. Which last names appear more than once ?
var result = ctx.Actor.GroupBy(x => x.LastName)
.Where(x => x.Count() > 1)
.OrderBy(x => x.Key)
.Select(x => x.First());
// 5. Which actor has appeared in the most films?
var result2 = (from actor in ctx.Actor
join film in ctx.FilmActor on actor.ActorId equals film.ActorId
group actor by new { actor.ActorId, actor.FirstName, actor.LastName } into newActor
select new
{
newActor.Key.ActorId,
newActor.Key.FirstName,
newActor.Key.LastName,
count = newActor.Sum(x => x.ActorId)
}).OrderByDescending(x => x.count).Take(1);
// 6. Is 'Academy Dinosaur' available for rent from Store 1 ?
var res = from film in ctx.Film
join store in ctx.Store on film.FilmId equals store.StoreId
where film.Title == "Academy Dinosaur" && store.StoreId == 1
select new { film.Title, store.StoreId };
// 7.Insert a record to represent Mary Smith renting 'Academy Dinosaur' from Mike Hillyer at Store 1 today
//var id = from c in ctx.Customer
// where c.LastName == "Smith" && c.FirstName == "Marry"
// select c.CustomerId;
//var xy = ctx.Customer.Where(x => x.FirstName == "Mary" && x.LastName == "Smith").Select(x => x.CustomerId).FirstOrDefault();
//var rental = new Rental()
//{
// CustomerId = xy,
// RentalDate = DateTime.Now,
// StaffId = 1,
// InventoryId = 1
//};
//ctx.Rental.Add(rental);
//ctx.SaveChanges();
//var res = (from c in ctx.Customer
// join r in ctx.Rental on c.CustomerId equals r.CustomerId
// join i in ctx.Inventory on r.InventoryId equals i.InventoryId
// join f in ctx.Film on i.FilmId equals f.FilmId
// where f.Title == "Academy Dinosaur"
// select new { c.FirstName, c.LastName }).OrderBy(x => x.LastName);
}
