Excluding properties from update instead of updating whole object

Question

Excluding properties from update instead of updating whole object

asp.net-mvc-5 aspnetboilerplate c# change-tracking entity-framework-6

Question

I am using ASP.NET Boilerplate with Code-First Entity Framework 6 and MVC 5.

In order to update an entity, I am using UpdateAsync.

How can I exclude some properties from the entity before executing update?

What function should I use and is this implemented in ASP.NET Boilerplate or not yet?

I have achieved that in Entity Framework 6 as follows:

public virtual TEntity UpdateWithExcludeProperities(TEntity entity,string [] properities)
{
    if (entity == null)
        throw new ArgumentException("Paramter cannot be null", "entity");

    var existedEntity = SelectFromContext(entity.ID);
    if (existedEntity == null)
        throw new ObjectNotFoundException("Record is not found!");

    _context.Entry(existedEntity).CurrentValues.SetValues(entity);
    foreach (var name in properities)
    {
        _context.Entry(existedEntity).Property(name).IsModified = false;
    }
    _context.SaveChanges();
    return existedEntity;
}

public virtual TEntity SelectFromContext(Guid id)
{
    TEntity entity;
    entity = DbSet<TEntity>().SingleOrDefault(e => e.ID == id);
    return entity;
}

But is there any possibility to implement this code in ASP.NET Boilerplate?

oula alshiekh

Popular Answer

you are on the wrong path! it's very simple to update an entity with the specified fields.

1- Create a DTO.

2- Configure mapping

3- Get entity and map DTO to entity.

Checkout my example. In this example Student entity has 3 properties. In the StudentAppService UpdateOnlyNameOfStudent() method, we update only Name field of Student. And notice that I even didn't run _studentRepository.Update(student) because AspNet Boilerplate commits the changes when the method ends (See automatic save change)

StudentDto.cs

[AutoMapFrom(typeof(Student))]
public class StudentDto: EntityDto<long>
{
     public string Name { get; set; }    
}

Student.cs

public class Student: Entity
{
     public string Name { get; set; }  

     public int SchoolNumber { get; set; }  

     public DateTime RegisterDate { get; set; }  
}

StudentAppService.cs

public class StudentAppService : IStudentAppService 
{
    private readonly IRepository<Student> _studentRepository;


    public RoleAppService(IRepository<Student> studentRepository)
    {
       _studentRepository = studentRepository;
    }

    public override async void UpdateOnlyNameOfStudent(StudentDto input)
    {
        var student = _studentRepository.Get(input.Id);
        ObjectMapper.Map(input, student);
    }

    /*
    public override async void UpdateOnlyNameOfStudent_Alternative(StudentDto input)
    {
        var student = _studentRepository.Get(input.Id);
        student.Name = input.Name;            
    }
    */
}

AspNet Boilerplate uses AutoMapper to map objects. See Object To Object Mapping

Alper Ebicoglu

View more on Stack Overflow

oula alshiekh · Accepted Answer · 4/15/2019 12:36:24 PM

i was able to do that in ASP.NET Boilerplate as following by working with Ef core LINQ queries directly only

public virtual TEntity SelectFromContext(TPrimaryKey id)
{
    TEntity entity;
    entity = Repository.GetDbContext().Set<TEntity>().SingleOrDefault(e => e.Id.Equals(id));
    return entity;
}

public virtual async Task<TEntity> UpdateWithExclude(TEntity entity, string[] properities)
{
        if (entity == null)
            throw new ArgumentException("Paramter cannot be null", "entity");

        var existedEntity = SelectFromContext(entity.Id);
        if (existedEntity == null)
            throw new ObjectNotFoundException("Record is not found!");

        var currentValues = Repository.GetDbContext().Entry(existedEntity).CurrentValues;

        foreach (var properteyName in currentValues.PropertyNames)//make default false value for all 
        {
            var y = Repository.GetDbContext().Entry(existedEntity).Property(properteyName);
            if (!properities.Contains(y.Name))
                Repository.GetDbContext().Entry(existedEntity).Property(properteyName).IsModified = false;
        }

        Repository.GetDbContext().Entry(existedEntity).CurrentValues.SetValues(entity);

        Repository.GetDbContext().SaveChanges();
        var UpdatedEntity = SelectFromContext(entity.Id);
        return await Task.FromResult(UpdatedEntity);
}

Excluding properties from update instead of updating whole object

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