c# - EF6: Modifying an entity property with a foreign key relation - Do I need to change the Id or the related object or both? -
i modifiying foreign key property on entity in code, modifiying id only: elementdata.servicelevelid = parameter.servicelevelid; i have found, after persisting, works expected, when corresponding navigation property servicelevel null accident. if still holds "old" object, change not hit database. this means, need do elementdata.servicelevelid = parameter.servicelevelid; elementdata.servicelevel = null; //force update database does mean, changing object "stronger" changing id only? should set related object null in such situations? update (per tim copenhaver's comment) : entity in question copy (with mentioned modification) of existing one. uses automapper copying, , maps except primary key , 1 unrelated property. automapper creates shallow copy afaik. thus, situation copy updated id , untouched object reference not match @ moment of adding context. guess, ef decides "object reference stronger". changing either property work l...