EF Core 5 many-to-many disconected add/remove without join entity class

Question

EF Core 5 introduced many-to-many by convention, we only need to add the collection navigation property on each side and it works.
I know I can query one side of the relationship, add it to the collection property and save it, but this requires an extra database trip.
Is it possible to add or remove using disconnected entities under this configuration?
I am aware that adding a intermediate class and mapping the join table would allow me to do this, I am asking about the many-to-many by convention way.

Answer 1

Hi DiegoTorres-0892,
There is a way to directly manipulate relationships for a many-to-many association but it requires to go down to the ObjectContext and its RelationshipManager which is pretty advanced and tricky.
The usual and straight-forward way to add and remove relationship entries to/from a many-to-many association is by just adding items to and removing items from the collections while the entities are attached to the context. EF's change tracking mechanism will recognize the changes you have done and generate the appropriate INSERT, UPDATE and DELETE statements when you call SaveChanges.
EF team will include a feature where we don't need to create a joining entity for many-to-many relationships in future. More discussion on GitHub you can refer to.
Best Regards,
Daniel Zhang

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