System.InvalidOperationException in EF core when trying to update

Question

Problem

I am creating a web app in asp.net core with ef core using with Repository pattern. Ii am trying to insert an entity it works fine when i trying to check whether it is already exist in db or then if yes than update the same entity in same api it gives me this error.

System.InvalidOperationException: 'The instance of entity type 'Consultation' cannot be tracked because another instance of this type with the same key is already being tracked. When adding new entities, for most key types a unique temporary key value will be created if no key is set (i.e. if the key property is assigned the default value for its type). If you are explicitly setting key values for new entities, ensure they do not collide with existing entities or temporary values generated for other new entities. When attaching existing entities, ensure that only one entity instance with a given key value is attached to the context.'

Image

code

insert api

[HttpPost]
public ApiResponse InsertConsultation([FromBody] Consultation consultation)
{
    if (!ModelState.IsValid)
    {
        return new ApiResponse(StatusCodes.Status400BadRequest, error: "error");
    }

    var consult = _consultationService.GetConsultationById(consultation.Id);

    if (consult !=null)
    {
        _consultationService.UpdateConsultation(consultation);
        return new ApiResponse(StatusCodes.Status200OK, success: "isSuccess");
    }

    _consultationService.InsertConsultation(consultation);
    return new ApiResponse(StatusCodes.Status201Created, success: "isSuccess");
}

score 1 · Accepted Answer · answered Aug 17 '17 at 05:00

1

The update process is

1- Retrieve the object which is consult in your code:

var consult = _consultationService.GetConsultationById(consultation.Id);

2- make change to the retrieval object (copy content from consultation to consult) you don't have it.

3- update the object consult

4- save change.

answered Aug 17 '17 at 05:00

Abdul Hadi

1,229
1
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I applied your suggestion but it throw the same exception – Malik Kashmiri Aug 17 '17 at 05:16
In step 2 you have to write code like `consult.Name=consultation.Name;` then try update `_consultationService.Update(consult);` if you still have error you need to catch the error in update method – Abdul Hadi Aug 17 '17 at 05:26
It works in this way but why I cant use this consult = consultation; – Malik Kashmiri Aug 17 '17 at 05:55
1

this method `consult = consultation;` is a Shallow copy and you need a Deep copy? you can implement IClonable and solve the problem – Abdul Hadi Aug 17 '17 at 06:09

score 0 · Answer 2 · edited May 05 '18 at 14:12

0

Maybe try this for the line before SaveChanges().

_context.AddOrUpdate(entity);

This needs the System.Data.Entity.Migrations namespace.

Your question might already be answered here: Update Row if it Exists Else Insert Logic with Entity Framework

edited May 05 '18 at 14:12

Irvin Dominin

30,819
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answered Aug 17 '17 at 04:57

Anthony McGrath

792
5
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System.InvalidOperationException in EF core when trying to update

Problem

Image

code

insert api

2 Answers2