EntityFramework 6.0.0 child object gets removed when json with empty array was sent-CodePudding

I'm currently having issue in the API that uses Entity framework and AutoMapper library where

I tried to update a request detail by passing a JSON object with a property that has an empty array as value in the request body like so:

{
  "id": 1,
  "name": "user 2",
  "active": true,
  "photos": []
}

but before I sent the request, the object is like this:

{
  "id": 1,
  "name": "user 1",
  "active": false,
  "photos": [
    {
      "filename": "filename.jpg",
      "imageType": "img/jpeg"
    }
  ]
}

after I submitted the JSON to the api and fetch the new value, the "photos" property also became empty like so:

{
  "id": 1,
  "name": "user 2",
  "active": true,
  "photos": []
}

here is also method I called in API side

public ActionResult Update([FromBody] RequestViewModel body)
{
  using (var dbContext = new PrimaryDbContext())
  {
    var data = dbContext.Set<Request>().Include("Photos").Where(r => r.Id == body.Id).FirstOrDefault();

    if(data == null) return NotFound();

    Mapper.Map(body, data);

    dbContext.SaveChanges();

    return Ok(data);
  }
}

Its just weird because it don't remove the photos before when I am passing the JSON with empty array to the API. I just don't get why this issue occurred now

CodePudding user response：

It updated Photos too because you included them in your select query. Try to remove photos from select

var data = dbContext.Set<Request>()
                    .Where(r => r.Id == body.Id)
                    .FirstOrDefault();

CodePudding user response：

Instead of removing the Include() method that the entity framework loads, I just configured the AutoMapper to exclude the mapping of Photos when passing the RequestViewModel's value into Request's properties like so:

From

    CreateMap<RequestViewModel,Request>();

    CreateMap<RequestViewModel,Request>()
        .ForMember(r => r.Id,o => o.MapFrom(rvm => rvm.Id))
        .ForMember(r => r.Name,o => o.MapFrom(rvm => rvm.Name))
        .ForMember(r => r.Active,o => o.MapFrom(rvm => rvm.Active))
        .ForAllOtherMembers(o => o.Ignore());