C# 如何在EF Core中附加具有现有父级和新子级的图形
如何在EF Core中添加子图形C# 如何在EF Core中附加具有现有父级和新子级的图形,c#,asp.net,entity-framework,entity-framework-core,disconnected-environment,C#,Asp.net,Entity Framework,Entity Framework Core,Disconnected Environment,如何在EF Core中添加子图形 private static void AttachGraphWithExistingParentNewChild() { Class class; using (var context = new SchoolContext()) { class = context.Classes.FirstOrDefault(s => s.Name
private static void AttachGraphWithExistingParentNewChild()
{
Class class;
using (var context = new SchoolContext())
{
class = context.Classes.FirstOrDefault(s => s.Name.Contains("AA"));
}
class.Students.Add(new Student{Name= "Youssef" });
using (var context = new SchoolContext())
{
context.ChangeTracker.TrackGraph(class, e=>e.Entry.State = EntityState.Added);
}
}
此方法将添加父项和子项,但这不是真的,我只想添加子项,让父项保持不变。您不能检查e.Entry.IsKeySet吗? e、 Entry.State=e.Entry.IsKeySet?EntityState.未更改:EntityState.已添加
(假设父项设置了Id,但子项没有设置)您不能检查e.Entry.IsKeySet吗? e、 Entry.State=e.Entry.IsKeySet?EntityState.未更改:EntityState.已添加 (假定父对象将设置Id,但子对象将不设置Id)