Hi

The solution will be simple but what is the best way to filter an collection with entities from an another collection.

I have two collections: A and B. A is filled with entities and collection B is empty.

When I add an entity in collection B, I want that this entity will filtered from 'defaultview' of collection A (but not deleted from collection).

What is the best way to do this in memory (self-services). Must I use one of the predicate classes?

Thank you.

Hi Robert,

You can create filtered-and-sorted views of your _EntityColllections _thanks to EntityViews. When you use entity views, the involved collection isn't changed. You can do that with normal _IPredicateExpressions _and _ISortExpressions _as you do with normal fetches.

Please read LLBLGenPro Help - Using generated code - SelfServicing - Using entityvies with entity collections.... and let us know if we can give you further assistance.

daelmo wrote:

Hi Robert,

You can create filtered-and-sorted views of your _EntityColllections _thanks to EntityViews. When you use entity views, the involved collection isn't changed. You can do that with normal _IPredicateExpressions _and _ISortExpressions _as you do with normal fetches.

Please read LLBLGenPro Help - Using generated code - SelfServicing - Using entityvies with entity collections.... and let us know if we can give you further assistance.

Hi daelmo,

Thank you for your reply.

I understand the filtering system and EntityView can help me with this, but my problem is how to filter the values of an EntityView from values from an another collection (or another Entityview).

Maybe I can give you an example. The interface has two listboxes. One listbox (A) contains all values of an EntityView (from a collection). Listbox B (another listbox with a collection) is empty.

When user double click (for example) an item in listbox A, this item must be placed in listbox B (in the another collection). No problem with that, but this item must be removed from listbox A (thus filtered on the EntityView of collection).

What is the best way to filter this EntityView with different values from an another collection? Of course I can use 'foreach' or something like that, but maybe is there an another option in the generated code of Predicate class that helps me with this.

There is no direct way. Try to filter in the PKs of the Entities added to the other collection.

In v2.5 you can though. With a MemberPredicate. Please see the example in using the generated code -> adapter/selfservicing -> Filtering and sorting -> The predicate system -> Member predicate