delete an entity without actually load it into the context

[AndreaT]

Hi,

is there a method to execute e database delete without the need to load the object into the db context  before calling DbCtx.Delete(obj)? By now what I do is:

1) get the object key from a grid/list
2) query/load the object from the dbcontext
3) perform a context.Delete(obi)
4) perform a context.SaveChanges() to persist the delete

In web application is a day-by-day task to bind grids  to object lists and perform a delete operation querying the object key from the grid itself. performing steps 1->4. is a huge waste of resources (and processing time).

best regards
Andrea

[Damyan Bogoev]

Hello AndreaT,

I am afraid that there is no other approach that you can use in this scenario. However, if the object has already been loaded in order to be shown in the grid, it is cached in the context instance used to retrieve it. So in most cases when you try to delete it, it will not be read again from the database but from the cache. Hope that helps.

Regards,
Damyan Bogoev
the Telerik team

[AndreaT]

Hi,

unfortunately in a web application the context is wiped out at the end of the page life cycle. Performing delete preloading the object is a havy duty (and unnecessary) job. It would be better to have a direct method to perform deletions.

thank you

Andrea

[Damyan Bogoev]

Hi AndreaT,

I think the only other solution you could use is to call a stored procedure which deletes the record from the database. Here are the steps you should follow:
1. Create a stored procedure on the sql server which can delete an object using its primary key;
2. Reverse map the stored procedure using the Update from Database wizard;
3. Execute the method which is mapped to the stored procedure:




...
context.StoredProcedureMethod(id);
...

Hope that helps.

Best wishes,
Damyan Bogoev
the Telerik team

[IT-Als]

Hi AndreaT and Damyan,

Sorry for interfering your thread, but another solution could be to enable the L2 cache. Especially since (as per the scenario AndreaT described) a list of objects are loaded initially and thus they are already present in the L2 cache.

So, as the L2 cache lives next to the L1 cache in the Scope/Context and never dies when a Scope/Context dies it will be a nice solution I guess.

Since the object is already loaded during display in web app, fetching it for delete will not hit the database (but go to the L2 cache for the object) and thus it can be deleted afterwards.

Just my thoughts,

Regards

Henrik

[Damyan Bogoev]

Hi Andrea,

Henrik is right, you can try the level 2 cache as well. Helpful information regarding the caching mechanisms in OpenAccess ORM can be found here, here and here. This help article demonstrates how to set the caching mechanism for your domain model.

Best wishes,
Damyan Bogoev
the Telerik team