static void UnionIntersectExcept()
{
using (SoccerContext db = new SoccerContext())
{
var players = db.Players.Where(p => p.Id < 10)
.Union(db.Players.Where(p => p.Team.Name.Contains("Basr")));
foreach (var p in players)
{
Console.WriteLine(p.Name);
}
Console.WriteLine("\n_______________________________\n");
var players2 = db.Players.Where(p => p.Id < 10)
.Intersect(db.Players.Where(p => p.Team.Name.Contains("Basr")));
foreach (var p in players2)
{
Console.WriteLine(p.Name);
}
Console.WriteLine("\n_______________________________\n");
var except1 = db.Players.Where(p => p.Id < 10);
var except2 = db.Players.Where(p => p.Team.Name.Contains("Basr"));
var players3 = except1.Except(except2);
foreach (var p in players3)
{
Console.WriteLine(p.Name);
}
}
}
static void LINQExtensions()
{
using (SoccerContext db = new SoccerContext())
{
var players = db.Players.Where(p => p.TeamId == 1);
}
}
static void AggregationOperatorsSQL()
{
using (SoccerContext db = new SoccerContext())
{
int number1 = db.Players.Count();
int number2 = db.Players.Count(p => p.Team.Name.Contains("Basr"));
Console.WriteLine("Count of players : {0}", number1);
Console.WriteLine("Count of Barcelona players : {0}", number2);
int minId = db.Players.Min(p => p.Id);
int maxId = db.Players.Max(p => p.Id);
double avgAge = db.Players.Where(p => p.Team.Name == "Basr")
.Average(p => p.Age);
Console.WriteLine("Min ID : {0}", minId);
Console.WriteLine("Max ID : {0}", maxId);
Console.WriteLine("Average age : {0}", avgAge);
int ageSum = db.Players.Sum(p => p.Age);
// суммарная цена всех моделей фирмы Samsung
int ageSumBar = db.Players.Where(p => p.Team.Name.Contains("Basr"))
.Sum(p => p.Age);
Console.WriteLine("Age sum : {0}", ageSum);
Console.WriteLine("Age sum of Barcelona : {0}", ageSumBar);
}
}
static void Group()
{
using (SoccerContext db = new SoccerContext())
{
var groups = from p in db.Players
group p by p.Team.Name;
foreach (var g in groups)
{
Console.WriteLine(g.Key);
foreach (var p in g)
{
Console.WriteLine("{0} - {1}", p.Name, p.Position);
}
Console.WriteLine();
}
//var groups = db.Players.GroupBy(p => p.Team.Name);
var groups2 = from p in db.Players
group p by p.Team.Name into g
select new { Name = g.Key, Count = g.Count() };
// альтернативный способ
//var groups2 = db.Players.GroupBy(p=>p.Team.Name)
// .Select(g => new { Name = g.Key, Count = g.Count()});
foreach (var c in groups2)
{
Console.WriteLine("Team: {0} Count of players: {1}", c.Name, c.Count);
}
}
}
static void OrderBy()
{
using (SoccerContext db = new SoccerContext())
{
var players = db.Players.OrderBy(p => p.Name);
foreach (Player p in players)
{
Console.WriteLine("{0}.{1} - {2}", p.Id, p.Name, p.Position);
}
players = db.Players.OrderByDescending(p => p.Name);
Console.WriteLine("___________________________________");
foreach (Player p in players)
{
Console.WriteLine("{0}.{1} - {2}", p.Id, p.Name, p.Position);
}
var PlayerCollection = db.Players.Select(p => new { Id = p.Id, Name = p.Name, Position = p.Position }).OrderBy(p => p.Name).ThenBy(p => p.Position);
foreach (var p in PlayerCollection)
{
Console.WriteLine("{0}.{1} - {2}", p.Id, p.Name, p.Position);
}
}
}
static void LINQToEntityObject()
{
using (SoccerContext db = new SoccerContext())
{
var players = db.Players.Where(p => p.Age < 30).ToList().Where(p => p.Id < 10);
}
}
static void FindFirst()
{
using (SoccerContext db = new SoccerContext())
{
Player player = db.Players.Find(2); // выберем элемент с id=2
Console.WriteLine(player);
player = db.Players.FirstOrDefault(p => p.Id == 3);
if (player != null)
{
Console.WriteLine(player.Name);
}
}
}
static void SimpleLINQ()
{
using (SoccerContext db = new SoccerContext())
{
var players = from p in db.Players
where p.TeamId == 1
select p;
foreach (var player in players)
{
Console.WriteLine(player.Name);
}
}
}
static void Delete()
{
using (SoccerContext db = new SoccerContext())
{
db.Database.ExecuteSqlCommand("ALTER TABLE dbo.Players ADD CONSTRAINT Players_Teams FOREIGN KEY (TeamId) REFERENCES dbo.Teams (Id) ON DELETE SET NULL");
//удаление игрока
Player pl_toDelete = db.Players.First(p => p.Name == "Роналду");
db.Players.Remove(pl_toDelete);
// удаление команды
Team t_toDelete = db.Teams.First();
db.Teams.Remove(t_toDelete);
db.SaveChanges();
}
}
static void Select()
{
using (SoccerContext db = new SoccerContext())
{
var players = db.Players.Select(p => new
{
Name = p.Name,
Position = p.Position,
Age = p.Age,
CommandName = p.Team.Name
});
foreach (var p in players)
{
Console.WriteLine("{0} ({1}) - {2} ... {3} years", p.Name, p.CommandName, p.Position, p.Age);
}
}
}
static void AsNoTracking()
{
using (SoccerContext db = new SoccerContext())
{
Player firstPlayer = db.Players.FirstOrDefault();
firstPlayer.Name = "Test";
//db.SaveChanges();
List <Player> players = db.Players.ToList();
//Player firstPlayer = db.Players.AsNoTracking().FirstOrDefault();
//firstPlayer.Name = "Test";
////db.SaveChanges();
//List<Player> players = db.Players.AsNoTracking().ToList();
}
}
static void Add()
{
using (SoccerContext db = new SoccerContext())
{
// создание и добавление моделей
Team t1 = new Team {
Name = "Барселона"
};
Team t2 = new Team {
Name = "Реал Мадрид"
};
db.Teams.Add(t1);
db.Teams.Add(t2);
db.SaveChanges();
Player pl1 = new Player {
Name = "Роналду", Age = 31, Position = "Нападающий", Team = t2
};
Player pl2 = new Player {
Name = "Месси", Age = 28, Position = "Нападающий", Team = t1
};
Player pl3 = new Player {
Name = "Хави", Age = 34, Position = "Полузащитник", Team = t1
};
db.Players.AddRange(new List <Player> {
pl1, pl2, pl3
});
db.SaveChanges();
// вывод
foreach (Player pl in db.Players.Include("Team"))
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Team != null ? pl.Team.Name : "");
}
Console.WriteLine();
foreach (Team t in db.Teams)
{
Console.WriteLine("Команда: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
}
}
static void Add()
{
using (SoccerContext db = new SoccerContext())
{
// создание и добавление моделей
Team t1 = new Team {
Name = "Basr"
};
Team t2 = new Team {
Name = "Real"
};
db.Teams.Add(t1);
db.Teams.Add(t2);
db.SaveChanges();
Player pl1 = new Player {
Name = "Ronal", Age = 31, Position = "Forward", Team = t2
};
Player pl2 = new Player {
Name = "Messi", Age = 28, Position = "Forward", Team = t1
};
Player pl3 = new Player {
Name = "Havi", Age = 34, Position = "Defence", Team = t1
};
db.Players.AddRange(new List <Player> {
pl1, pl2, pl3
});
db.SaveChanges();
// вывод
foreach (Player pl in db.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Team != null ? pl.Team.Name : "");
}
Console.WriteLine();
foreach (Team t in db.Teams)
{
Console.WriteLine("Team: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
}
}
static void Change()
{
using (SoccerContext db = new SoccerContext())
{
Player player = db.Players.Where(p => p.Name == "Месси").FirstOrDefault <Player>();
player.Name = "Месси №1";
db.SaveChanges();
foreach (Team t in db.Teams.Include("Players"))
{
Console.WriteLine("Команда: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
}
}
static void Change()
{
using (SoccerContext db = new SoccerContext())
{
Player player = db.Players.Where(p => p.Name == "Месси").First <Player>();
Team team = db.Teams.Where(p => p.Name == "Барселона").First <Team>();
team.Players.Remove(player);
db.SaveChanges();
foreach (Team t in db.Teams.Include("Players"))
{
Console.WriteLine("Команда: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
}
}
static void Change()
{
using (SoccerContext db = new SoccerContext())
{
//Player player = null;
//foreach(Player p in db.Players)
//{
// if(p.Name == "Messi")
// {
// player = p;
// break;
// }
//}
//if (player != null)
//{
// player.Name = "Messi #1";
// db.SaveChanges();
//}
//Player player = db.Players.Where(p => p.Name == "Messi").First<Player>();
//player.Name = "Messi №1";
//db.SaveChanges();
foreach (Team t in db.Teams.Include("Players"))
{
Console.WriteLine("Team: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
foreach (Team t in db.Teams)
{
Console.WriteLine("Team: {0}", t.Name);
foreach (Player pl in t.Players)
{
Console.WriteLine("{0} - {1}", pl.Name, pl.Position);
}
Console.WriteLine();
}
}
}
static void Join()
{
using (SoccerContext db = new SoccerContext())
{
//var players = from p in db.Players
// join c in db.Teams on p.TeamId equals c.Id
// select new { Name = p.Name, Team = c.Name, Position = p.Position };
var players = db.Players.Join(db.Teams, // вторая таблица для соединения
x => x.TeamId, // свойство из первой таблицы для соединения
c => c.Id, // свойство из второй таблицы для соединения
(p, c) => new // новый результативный объект
{
Name = p.Name,
Team = c.Name,
Position = p.Position
});
foreach (var p in players)
{
Console.WriteLine("{0} ({1}) - {2}", p.Name, p.Team, p.Position);
}
}
}
