add several references to the same record in navigation property
<p>In my EF 6 Model First application, I have an entity with a many-to-many navigation property to another entity. In the first entity, I need to add several references to the same record in navigation property. </p>

<p>The first entity is a “saleslistItem” and the second entity is “warehouseItem”. Normally there will be a one-to-one relationship here, but exceptionally there will be some bundles where one “saleslistItem” contains several “warehouseItems”. “WarehouseItem” can also be included in several “salesListItems”. At the end of the project, my customer says, testing it, that “saleslistItem” must be able to consist of several “WarehouseItems” of the same kind (like two boxes of smoked ham).</p>

<p>These data is used several places in my code. (ie. doing a sale removes items from the warehouse) If I could just add several the same reference, my code would work without any modifications. But in the implementation of the navigation property the “hashtable”-collection is used, and this collection requires unique entries. Is there a workaround here? Performance is irrelevant as the data amount is small.</p>

<p>If there are no such workaround, is it possible to store values together with the instance of navigation property? Maybe it is implemented as a field in the join-table???</p>

<p>Any other suggestions?
Need a solution so the customer pays the last part of the bill!</p>