static void Main(string[] args) { Console.WriteLine($"Setup..."); using (var context = new MyDbContext(useLazyLoading: false)) { context.Database.EnsureDeleted(); context.Database.EnsureCreated(); var parent = new Parent { Child = new ConcreteChild { GrandChildren = new List <GrandChild> { new GrandChild() } } }; context.Parents.Add(parent); context.SaveChanges(); } Console.WriteLine($"Eagerly loading GrandChild entities fails (lazy loading ENABLED, no tracking)"); try { using (var context = new MyDbContext(useLazyLoading: true)) { var results = context.Parents .AsNoTracking() .Include(x => x.Child.GrandChildren) .ToList(); var child = results.Single().Child; // Exception is thrown when accessing child.GrandChildren Console.WriteLine($"GrandChildren.Count: {child.GrandChildren.Count}"); } } catch (Exception ex) { Console.WriteLine($"Exception: {ex.Message}"); } Console.WriteLine(); Console.WriteLine("----------------------------------------------"); Console.WriteLine(); Console.WriteLine($"Eagerly loading too many GrandChild entities (lazy loading DISABLED, no tracking)"); using (var context = new MyDbContext(useLazyLoading: false)) { var results = context.Parents .AsNoTracking() .Include(x => x.Child.GrandChildren) .Select(parent => new { Parent = parent, Child = parent.Child }) .ToList(); var child = results.Single().Child; Console.WriteLine($"GrandChildren.Count expected: 1"); Console.WriteLine($"GrandChildren.Count actual: {child.GrandChildren.Count}"); } }
public Form1() { InitializeComponent(); initializeDateTimePicker(); dataGridView1.AllowUserToAddRows = false; dataGridView1.AllowUserToDeleteRows = false; buttonAdd.Click += buttonAdd_Click; buttonDelete.Click += buttonDelete_Click; buttonEdit.Click += buttonEdit_Click; using (MyDbContext context = new MyDbContext()) { context.Database.EnsureCreated(); } using (MyDbContext context = new MyDbContext()) { context.Database.EnsureCreated(); MyData data = context.Find <MyData>(1u); if (null != data) { Console.WriteLine("Found"); Console.WriteLine(data.Name); } else { Console.WriteLine("Not Found"); } BindingSource bi = new BindingSource(); bi.DataSource = context.Find <MyData>(1u); dataGridView1.DataSource = bi; dataGridView1.Refresh(); } using (MyDbContext context = new MyDbContext()) { context.Database.EnsureCreated(); MyData found = null; foreach (var item in from data in context.Data where data.Key == 1 select data) { found = item; break; } if (null == found) { return; } //found.Number++; context.SaveChanges(); } using (MyDbContext context = new MyDbContext()) { context.Add(new MyData() { Name = "이름", Number = 123 }); context.SaveChanges(); } }
public void Create(StudentEntity student) { _ctx.Students.Add(student); _ctx.SaveChanges(); }
public ProductEntity CreateProduct(ProductEntity product) { product = _ctx.Products.Add(product); _ctx.SaveChanges(); return(product); }