Creating and Inserting new entity from Existing One in Linq To Sql

Question

I have 2 tables; PriceList and PriceListDetail with one to many realitonship. After inserting a new PriceList and I need to copy PriceListDetail's of an existing PriceList.

var pricedetails= db.PriceListDetails.Where(p => p.PriceList Id == SomeExistingPriceListID);

All I need is to change priceListID of pricedetails above and Insert them to PriceListDetail table. When I modify priceListId of pricedetails and try to insert them I get 'cannot insert entities that already exists'.

Obvious solution is to create new entities and copy values one by one from pricedetails then insert.

Is there a way to avoid one by one copying? Maybe create duplicate rows then modify duplicated ones?

Answer 1

Entity frameworks uses another key than your primary key, and it is called an entity key . So having your PriceListDetails, all you have to do is to change the primary key ID and set the entity key to NULL (NULL means a new row).