EF代码优先更新方法不起作用

Question

i have this class

public class BankAccount : IEntity
{
    public int Id { get; set; }
    public long AccountNumber { get; set; }
    public string Description { get; set; }
    public bool IsFund { get; set; }

    public virtual Person Owner { get; set; }
    public virtual Branch Branch { get; set; }

    public BankAccount()
    {
        AccountNumber = 0;
        IsFund = false;
        Description = "Empty";
    }
}

and update method:

public void Update(DBS.BankAccount entity)
{
    try
    {
        using (var _nahidContext = new NahidContext())
        {
            var bankAccountElement= FindById(entity.Id);
            _nahidContext.Entry(bankAccountElement).State = System.Data.Entity.EntityState.Modified;
            var bankAccount = _nahidContext.Entry(bankAccountElement);
            bankAccount.CurrentValues.SetValues(entity);
            _nahidContext.SaveChanges();
        }
    }
    catch (Exception ex)
    {
        throw new ArgumentException(ex.Message);
    }
}

when i run update method and change (owner,branch,description) value just description does change and owner,branch haven't any change. how can i change owner or branch?[Thanks]

Answer 1

There are two ways that I know of to solve this.

Add foreign key as property:

public class BankAccount : IEntity
{
    public int Id { get; set; }
    public long AccountNumber { get; set; }
    public string Description { get; set; }
    public bool IsFund { get; set; }

    public int OwnerID { get; set; }
    [ForeignKey("OwnerID")]
    public virtual Person Owner { get; set; }

    public int BranchID { get; set; }
    [ForeignKey("BranchID")]
    public virtual Branch Branch { get; set; }

    public BankAccount()
    {
        AccountNumber = 0;
        IsFund = false;
        Description = "Empty";
    }
}

This should update the relation, but not the Person or Branch . Those need to be updated separately, the same way you're updating BankAccount .

Update the linked by assigning Owner and Branch.

public void Update(DBS.BankAccount newBankAccount)
{
    try
    {
        using (var _nahidContext = new NahidContext())
        {
            BankAccount oldBankAccount = FindById(entity.Id);

            oldBankAccount.Owner = newBankAccount.Owner;
            oldBankAccount.Branch = newBankAccount.Branch;
            oldBankAccount.CurrentValues.SetValues(newBankAccount);

            _nahidContext.SaveChanges();
        }
    }
    catch (Exception ex)
    {
        throw new ArgumentException(ex.Message);
    }
}

This will however create a new Person and a new Branch .