static void Main(string[] args)
{
Console.WriteLine("Hello World Entity Framework Core!");
using (var context = new VideoGamesDatabaseContext()) {
// Migrate the database
context.Database.Migrate();
// Verify that all previous data is kept
Console.WriteLine("Current database content");
foreach (var videoGame in context.VideoGames.ToList())
{
Console.WriteLine($"{videoGame.Title} - {videoGame.Platform} - {videoGame.ReleaseYear}");
}
// Add a video game with its release year filled
context.VideoGames.Add(new VideoGame {
Title = "Final Fantasy XV",
Platform = "PS4",
ReleaseYear = 2016
});
context.SaveChanges();
// Fetch all video games
Console.WriteLine("Current database content");
foreach (var videoGame in context.VideoGames.ToList())
{
Console.WriteLine($"{videoGame.Title} - {videoGame.Platform} - {videoGame.ReleaseYear}");
}
}
}
static void Main(string[] args)
{
Console.WriteLine("Hello World Entity Framework Core!");
using (var context = new VideoGamesDatabaseContext())
{
// Migrate the database
context.Database.Migrate();
//delete all previous entitiies
foreach (var videoGame in context.VideoGames)
{
context.Remove(videoGame);
}
context.SaveChanges();
}
var results = new List <ExecutionResult>();
results.Add(MeasureDelete("All 500 entities", 500, vg => true));
results.Add(MeasureDelete("All 500 entities 2", 500, vg => true));
results.Add(MeasureDelete("500 entities, year > 250", 500, vg => vg.ReleaseYear > 250));
results.Add(MeasureDelete("All 2000 entities", 2000, vg => true));
results.Add(MeasureDelete("2000 entities, year > 1000", 2000, vg => vg.ReleaseYear > 1000));
results.Add(MeasureDelete("All 10000 entities", 10000, vg => vg.ReleaseYear > 1000));
results.Add(MeasureDelete("10000 entities, year > 5000", 10000, vg => vg.ReleaseYear > 5000));
Console.WriteLine("No batch(ms) Batch(ms) Title");
Console.WriteLine(string.Join("\n", results));
}
static void Main(string[] args)
{
Console.WriteLine("Hello World Entity Framework Core!");
using (var context = new VideoGamesDatabaseContext()) {
//The line below clears and resets the databse.
context.Database.EnsureDeleted();
// Create the database if it does not exist
context.Database.EnsureCreated();
// Add some video games.
//Note that the Id field is autoincremented by default
context.VideoGames.Add(new VideoGame {
Title = "Persona 5",
Platform = "PS4"
});
var SG = new VideoGame();
SG.Title = "Steins's Gate";
SG.Platform = "PSVita";
context.VideoGames.Add(SG);
//Commit changes by calling save changes
context.SaveChanges();
// Fetch all video games
Console.WriteLine("Current database content");
foreach (var videoGame in context.VideoGames.ToList())
{
Console.WriteLine($"{videoGame.Title} - {videoGame.Platform}");
}
// Fetch all PS4 games
var ps4Games = from v in context.VideoGames where v.Platform == "PS4"
select v;
Console.WriteLine("PS4 Games");
foreach (var videoGame in ps4Games)
{
Console.WriteLine($"{videoGame.Title} - {videoGame.Platform}");
}
//delete ps4 games
Console.WriteLine("Deleting PS4 Games");
context.VideoGames.RemoveRange(ps4Games);
//Do not forget to commit changes by calling save changes
context.SaveChanges();
Console.WriteLine("Current database content");
foreach (var videoGame in context.VideoGames)
{
Console.WriteLine($"{videoGame.Title} - {videoGame.Platform}");
}
}
}
static ExecutionResult MeasureDelete(string title, int count, Func <VideoGame, bool> predicate)
{
TimeSpan duration;
DateTime start;
var result = new ExecutionResult();
result.Title = title;
FillDatabase(count);
Console.WriteLine("Start classic delete");
using (var context = new VideoGamesDatabaseContext())
{
start = DateTime.Now;
//delete all previous entitiies
foreach (var videoGame in context.VideoGames.Where(predicate))
{
context.Remove(videoGame);
}
context.SaveChanges();
duration = DateTime.Now - start;
}
result.ClassicTime = duration.TotalMilliseconds;
Console.WriteLine($"Finished classic delete time {duration.Ticks}");
FillDatabase(count);
Console.WriteLine("Starting batch delete");
using (var context = new VideoGamesDatabaseContext())
{
start = DateTime.Now;
var res = context.VideoGames.Where(vg => predicate(vg)).Delete(x => x.BatchSize = 500);
//no need to save context
duration = DateTime.Now - start;
}
result.BatchTime = duration.TotalMilliseconds;
Console.WriteLine($"Finished batch delete time {duration.Ticks}");
return(result);
}
static void FillDatabase(int count)
{
Console.WriteLine("start adding");
using (var context = new VideoGamesDatabaseContext())
{
for (int i = 0; i < count; i++)
{
var vg = new VideoGame
{
Platform = "PS4",
Title = $"Game {i}",
ReleaseYear = i
};
context.Add(vg);
}
context.SaveChanges();
}
Console.WriteLine("Finished adding");
}