CODEWITHSUNDEEP
c#entity-framework-6
Sohlae
Sohlae

Reputation: 766

DbContext.Update Method Sets My Foreign Key To Null

I am currently experiencing a weird problem with EF. Let's say I have the following information in my database. Department ID is a foreign key to the Departments table.

enter image description here

Whenever I make an update to this record by calling the DbContext.Update method it sets the Department ID to null. The only time that it does not do this is when I make a change to the Department ID itself.

var employeeDto = new EmployeeDto
{
    Id = 3 // assume that the primary key of this record is 3.
    Name = "Motea Dave",
    UserId = "123123",
    DepartmentId = 3
};

var employee = Mapper.Map<Employee>(employeeDto);
_employeeRepository.Update(employee, employee.Id);
_unitOfWork.SaveChanges(); // When I set my breakpoint here and inspect _employeeRepository I can already see that the DepartmentId has been set to null.


//Employee Repository
public class EmployeeRepository : RepositoryBase<Employee>
{
    // Repository code here...
}


//Repository Base
public abstract class RepositoryBase<T> where T : class
{
    private readonly IUnitOfWork unitOfWork

    public RepositoryBase(IUnitOfWork unitOfWork) 
    {
        this.unitOfWork = unitOfWork; 
    }

    public virtual void Update(T entity, int id)
    {
        var item = this.Dataset.Find(id);

        item.Copy(entity);
        item.Id = id;

        this.unitOfWork.Context.Update<T>(item); //unitOfWork.Context is basically DbContext of Entity Framework.
    }
}

Removing the Update method and calling SaveChanges() directly does not help either.

Upvotes: 0

Views: 70

Answers (1)

TheGeneral
TheGeneral

Reputation: 81503

This seems like an AutoMapper problem and not Entity Framework 

var employee = Mapper.Map<Employee>(employeeDto);

If this line sets your DepartmentId to null, consult your mapping and make sure you haven't ignored the property, or if need be make a mapping for it

Update

It does not. Before executing _employeeRepository.Update() I checked the employee variable first and the DepartmentId (3) is there. It becomes null as soon as I execute the _employeeRepository.Update() method which is confusing.

Then its likely with your repository code, it would be extremely unlikely for entity framework to null out a value with an Attach and saveChanges

However, you will need to put the relevant repository code in your question

Upvotes: 1

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