C#•3y ago

❔ Entity framework, tracking same Id multiple times. Need help

EmreOP•10/7/23, 11:37 AM

getting following error:

Could not insert Azure DevOps projects and work items into the database. Exception: The instance of entity type 'WorkItem' cannot be tracked because another instance with the same key value for {'WorkItemId'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.

EmreOP•10/7/23, 11:37 AM

Im a beginner in entityframework

EEmre getting following error: Could not insert Azure DevOps projects and work items ...

Brainiac V•10/7/23, 11:40 AM

Why are you trying to update an entity like this in the first place at all?

Brainiac V•10/7/23, 11:40 AM

Where did you learn that from?

EmreOP•10/7/23, 11:41 AM

I usually work with TSQL so i didnt really learn it really

EmreOP•10/7/23, 11:41 AM

can you tell me what im doing wrong

EmreOP•10/7/23, 11:41 AM

@Brainiac V

EEmre I usually work with TSQL so i didnt really learn it really

Brainiac V•10/7/23, 11:42 AM

So why not reading through examples or tutorials?

EmreOP•10/7/23, 11:44 AM

I always find it hard to go through general tutorials. I try to watch some videos to get a general understanding and once I get stuck, i learn by solving them. If you have any tutorial that fits my scenario more specifically id appreciate if you could send it

EEmre I always find it hard to go through general tutorials. I try to watch some video...

Brainiac V•10/7/23, 11:48 AM

So the first thing you need to make sure is through debugging is that you don't have two WorkItem entities with the same WorkItemId

Brainiac V•10/7/23, 11:49 AM

Because that's what EF Core is complaining about right now

EmreOP•10/7/23, 11:53 AM

I cant have multiple workitems with same id because these are fetched from azure devops which is always incremented automatically. It must be something with my existingWorkItem when i query the database

EmreOP•10/7/23, 11:54 AM

I read alittle about entity framework tracking. So I guess its tracking the workitem while trying to update the fields for that same workitemId

Brainiac V•10/7/23, 11:54 AM

But the real problem here seems to be, that you first fetch existing items without tracking by EF Core, then you modify them, then you attach them to the context and change the state. The issue is probably that at the moment in your application you already have that item tracked by EF Core and that then causes issues.

Brainiac V•10/7/23, 11:54 AM

So to solve it, you can fetch the original items in a tracked way and modify them, so EF Core knows about it

EmreOP•10/7/23, 11:55 AM

I added the no tracking in order to bypass my error. Which also didn't work

Brainiac V•10/7/23, 11:55 AM

So you can also remove this code:

_mainDbContext.WorkItems.Attach(existingWorkItem);
_mainDbContext.Entry(existingWorkItem).State = EntityState.Modified;

_mainDbContext.WorkItems.Attach(existingWorkItem);
_mainDbContext.Entry(existingWorkItem).State = EntityState.Modified;

Brainiac V•10/7/23, 11:56 AM

Also don't use SaveChangesAsync as long as you really don't know what the consequences are

TeBeCo•10/7/23, 11:56 AM

i don't understand the .AsNoTracking.AsNoTracking as you literally track if it exists after

TeBeCo•10/7/23, 11:57 AM

Brainiac V•10/7/23, 11:57 AM

So to solve your problem, let EF Core track your fetched items properly from fetching the data

Brainiac V•10/7/23, 11:57 AM

Then modify your data and just call save without async

TeBeCo•10/7/23, 11:57 AM

a yeah and also

Brainiac V•10/7/23, 11:58 AM

Then none of the problems above should happen

TeBeCo•10/7/23, 11:58 AM

I would remove that FirstOrDefaultAsyncFirstOrDefaultAsync from the loop

TeBeCo•10/7/23, 11:58 AM

seems bad

TeBeCo•10/7/23, 11:58 AM

I would just query is all with a ToListAsync

TeBeCo•10/7/23, 11:58 AM

update them all locally / normal tracking

TeBeCo•10/7/23, 11:58 AM

and all the one missing a simple .Add ... locally

TeBeCo•10/7/23, 11:58 AM

and then SaveCahngeAsync

TeBeCo•10/7/23, 11:59 AM

EmreOP•10/7/23, 11:59 AM

that wouldn't be optimal in my case. Because there can be hundreds of workitems per project

TeBeCo•10/7/23, 11:59 AM

that would literally be the same

TeBeCo•10/7/23, 11:59 AM

if not better

TeBeCo•10/7/23, 11:59 AM

because you're literally doing 5000 request now for 5000 items

TeBeCo•10/7/23, 11:59 AM

you would just do 3 call

TeBeCo•10/7/23, 11:59 AM

¯\_(ツ)_/¯

TeBeCo•10/7/23, 12:00 PM

the fact that you hit the db every single time is literally worse for your scenario

EmreOP•10/7/23, 12:01 PM

i think i understand what you mean now

TeBeCo•10/7/23, 12:02 PM

got to go soneobe just woke up here

TeBeCo•10/7/23, 12:02 PM

EmreOP•10/7/23, 12:02 PM

hahah thanks

Accord•10/8/23, 12:31 PM

Was this issue resolved? If so, run

/close

/close

- otherwise I will mark this as stale and this post will be archived until there is new activity.

❔ Entity framework, tracking same Id multiple times. Need help

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