N plus one (ARCH203)

Anahtar dotnet.ef.n-plus-one · Onem warning · Kategori ef

Her dongu adiminda iliskili veriye erisim, ana sorguya ek olarak her satir icin ayri bir sorgu calistirir (N+1 problemi).

Hatali

var blogs = await _db.Blogs.ToListAsync();
foreach (var blog in blogs)
{
    Console.WriteLine(blog.Posts.Count); // extra query each loop
}

Dogru

var blogs = await _db.Blogs
    .Include(b => b.Posts)
    .ToListAsync();
foreach (var blog in blogs)
{
    Console.WriteLine(blog.Posts.Count);
}

Duzeltme

Iliskili veriyi Include() ile tek seferde eager load edin.