问有时，实体框架在将“子”添加到新(父)元素后插入多个“父”行。

EN

public class Parent
{
    public int Id { get; set; }
    public List<Child> Children { get; set; }
    public string Name { get; set; }
    public Parent()
    {
        Children = new List<Child>();
    }
}

public class Child
{
    public int Id { get; set; }
    public Parent Parent { get; set; }
    public int ParentId { get; set; }
    public string ParentName { get; set; }
}

public void ProcessChildren()
{
    IDbContextTransaction trans = dbContext.BeginTransaction();
    foreach(var item in Children) //Children is a list of child entities (existing in the DB)
    {
        var parent = dbContext.Parents.SingleOrDefault(x => x.Name == item.ParentName);
        if(parent == null)
        {
            parent = new Parent{Name = item.ParentName};
            dbContext.Parents.Add(parent);
        }
        parent.Children.Add(item);
        dbContext.SaveChanges();
    }
    trans.Commit(); //rollback implemented if it fails
}