AsEnumerable() is effectively a cast to IEnumerable<T>, which makes member resolution find members of Enumerable instead of Queryable. It’s usually used when you want to force part of a query to run as SQL (or similar), and the remainder to run using LINQ to Objects. See my Edulinq blog post on it for more information. … Read more
You could do so. It’s technically possible. But it does (design)functionally not make any sense. You’re basically tight-coupling the model with the controller. Usually the JPA entity (model) is a property of a JSF managed bean (controller). This keeps the code DRY. You don’t want to duplicate the same properties over all place, let alone … Read more
There is opportunity for several improvements (if you are using DbContext): Set: yourContext.Configuration.AutoDetectChangesEnabled = false; yourContext.Configuration.ValidateOnSaveEnabled = false; Do SaveChanges() in packages of 100 inserts… or you can try with packages of 1000 items and see the changes in performance. Since during all this inserts, the context is the same and it is getting bigger, … Read more
JPA specification contains a very precise description of semantics of these operations, better than in javadoc: The semantics of the persist operation, applied to an entity X are as follows: If X is a new entity, it becomes managed. The entity X will be entered into the database at or before transaction commit or as … Read more
Ladislav’s answer updated to use DbContext (introduced in EF 4.1): public void ChangePassword(int userId, string password) { var user = new User() { Id = userId, Password = password }; using (var db = new MyEfContextName()) { db.Users.Attach(user); db.Entry(user).Property(x => x.Password).IsModified = true; db.SaveChanges(); } }
How to fix the Hibernate “object references an unsaved transient instance – save the transient instance before flushing” error
The solution is simple, just use the CascadeType.MERGE instead of CascadeType.PERSIST or CascadeType.ALL. I have had the same problem and CascadeType.MERGE has worked for me. I hope you are sorted.