MERGE in Entity Framework
Is there a way t开发者_StackOverflowo call T-Sql's MERGE command from .NET Entity framework 4?
No there no such built-in functionality - you must build your own. Very common is for example approach like:
public void SaveOrUpdate(MyEntity entity)
{
if (entity.Id == 0)
{
context.MyEntities.AddObject(entity);
}
else
{
context.MyEntities.Attach(entity);
context.ObjectStateManager.ChangeObjectState(entity, EntityState.Modified);
}
// You can call SaveChanges here or you can call it separately after multiple changes
}
This is example for working with detached entity which have Id
auto generated in the database (IDENTITY
). Default Id for new entity is always 0 because the real value will be assigned during saving changes.
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