code first - EF 4 CTP 5: Trouble trying to remove an entity -

i have created model poco class called recipe; corresponding reciperepository persists these objects. using code first on top of existing database.

every recipe contains icollection<recipecategory> of categories link recipes , categories table in many-to-many relationship. recipecategory contains corresponding 2 foreign keys.

a simplified version of controller , repository logic looks (i have commented out checks authorization, null objects etc. simplicity):

public actionresult delete(int id) {     _reciperepository.remove(id);      return view("deleted"); } 

the repository's remove method nothing following:

public void remove(int id) {     recipe recipe = _context.recipes.find(id);     _context.recipes.remove(recipe);     _context.savechanges(); } 

howevery, code above not work since receive system.invalidoperationexception every time run it: adding relationship entity in deleted state not allowed.

what error message stand , how can solve problem? thing try achieve deleting entity.

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@ladislav: have replaced icollection<recipecategory> icollection<category>. accidentially, resharper refactored away virtual keyword.

however, problem remains — cannot delete category recipe entity. following code not persist deletion of categories database:

private void removeallcategoriesassignedtorecipe() {     foreach (category category in _recipe.categories.toarray())     {         _recipe.categories.remove(category);         category.recipes.remove(_recipe);     }      _context.savechanges(); } 

i have debugged code , can confirm collections modified correctly — is, contain no elements after loop (i have used clear() method). after calling savechanges(), populated again.

what doing wrong?

(maybe important: using singleton pattern have 1 instance of context.)

i able solve problem following way:

private void removeallcategoriesassignedtorecipe() {     foreach (category category in _recipe.categories.toarray())     {         category categoryentity = _categoryrepository.retrieve(category.categoryid);          var recipesassignedtocategory = categoryentity.recipes.toarray();         categoryentity.recipes.clear();          foreach (recipe assignedrecipe in recipesassignedtocategory)         {             if (assignedrecipe.recipeid == _recipe.recipeid)             {                 continue;             }              categoryentity.recipes.add(assignedrecipe);         }          _context.entry(categoryentity).state = entitystate.modified;     }      _recipe.categories.clear();     _context.savechanges(); }