EF Update Navigation Properties

In short, to make all things, are DbContext managed state

1, check out, change, and then submit

2, new out, attach, then change, and then submit

Both of the above are better understood

3, new out, changed, and then attach, in the state of change, and then submit

Change state here, it is not the same as the normal property (X=>x.?). Ismodify=true, navigation properties cannot be used in this way

Because the navigation property corresponds to a collection, and the state is to correspond to the specific state of each element in the collection, rather than the entire state of the collection

((iobjectcontextadapter) db). ObjectContext.ObjectStateManager.ChangeRelationshipState (sourceentitytargetentity, Navigationpropertyselector, relationshipstate);

The statement is slightly cumbersome

Object of the first primary table

The second is a specific object in the Navigation property collection

The third is the navigation property of the primary Table object x=>x. Properties

The last one is the state

EF Update Navigation Properties