Violation of PRIMARY KEY constraint 'PK_dbo.AmazonProducts'. Cannot insert duplicate key in object
c#, entity-framework
Solution
This line:
amazonProductCompetitivePrice.AmazonProduct = amazonProduct;
adds `amazonProduct` instance to context implicitly. Because that instance was retrieved with different instance of context, current instance thinks, that it is new `AmazonProduct`. You should attach it instead, something like this:
if (amazonProductCompetitivePrice.AmazonProduct != null && amazonProductCompetitivePrice.AmazonProduct.Id != 0)
{
context.Entry(amazonProductCompetitivePrice.AmazonProduct).State = EntityState.Unchanged;
}
Another way: you can set foreign key property only for `amazonProductCompetitivePrice` instead of navigation property.
Problem
I have a problem trying to save an entity which is a foreign key to a parent object.. i have an amazonProduct entity. And an AmazonCompetitivePrice entity which is a virtual list on the amazonProduct like so : ``` public class AmazonProduct { [Key] [DatabaseGenerated(DatabaseGeneratedOption.None)] public virtual int ASIN public virtual IList<AmazonProductCompetitivePrice> amazonProductCompetitivePrices = new List<AmazonProductCompetitivePrice>(); } ``` So i have a AmazonProduct which i retrieve from the database, and then add a new AmazonProductCompetitivePrice to the amazonProduct. But when i try save this, I get the following error: Violation of PRIMARY KEY constraint 'PK_dbo.AmazonProducts'. Cannot insert duplicate key in object 'dbo.AmazonProducts'.\r\nThe statement has been terminated It looks like its not realising that my AmazonProduct is already in the database, and its trying to save a new one but the primary key already exists! I used the fluent API to map the foreign key like so: ``` modelBuilder.Entity<AmazonProduct>() .HasMany(pl => pl.AmazonProductCompetitivePrices) .WithOptional(p => p.AmazonProduct) .Map(c => c.MapKey("ASIN")); ``` Anyone know whats wrong with this? Thanks in advance! EDIT: object retrieval: ``` using (var uow = new UnitOfWorkInventory()) { using (var amazRepo = new AmazonProductRepository(uow)) { return amazRepo.FindByAsin(ASIN); } } public AmazonProduct FindByAsin(string asin) { return context.AmazonProducts.Include(x => x.AmazonLowestOfferListings).Include(x => x.AmazonMyPrices).Include(x => x.AmazonProductCompetitivePrices).SingleOrDefault(x => x.ASIN == asin); } ``` That gets me the AmazonProduct.. then the save: ``` using (var uow = new UnitOfWorkInventory()) { using (var amazonRepo = new AmazonProductCompetitivePriceRepository(uow)) { amazonProductCompetitivePrice.AmazonProduct = amazonProduct; amazonRepo.InsertOrUpdate(amazonProductCompetitivePrice); } uow.Commit(); } public void InsertOrUpdate(AmazonProductCompetitivePrice amazonProductCompetitivePrice) { if (amazonProductCompetitivePrice.Id == default(int)) { // New entity context.AmazonProductCompetitivePrices.Add(amazonProductCompetitivePrice); } else { // Existing entity context.Entry(amazonProductCompetitivePrice).State = EntityState.Modified; } } ``` Thats everything.. and thanks for the help!!