How to clone a JPA entity
Use EntityManager.detach. It makes the bean no longer linked to the EntityManager. Then set the Id to the new Id (or null if automatic), change the fields that you need and persist.
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How can I get my database to seed using Entity Framework CodeFirst?
This is what my DbContext classes all look like and they seed just fine: public class MyDbContext : DbContext { public DbSet<MyClass> MyClasses { get; set; } protected override void OnModelCreating (DbModelBuilder modelBuilder) { base.OnModelCreating (modelBuilder); modelBuilder.Conventions.Remove<System.Data.Entity.ModelConfiguration.Conventions.PluralizingTableNameConvention> (); // Add any configuration or mapping stuff here } public void Seed (MyDbContext Context) { #if DEBUG … Read more
Symfony2 collection of Entities – how to add/remove association with existing entities?
I’ve come to the same conclusion that there’s something wrong with the Form component and can’t see an easy way to fix it. However, I’ve come up with a slightly less cumbersome workaround solution that is completely generic; it doesn’t have any hard-coded knowledge of entities/attributes so will fix any collection it comes across: Simpler, … Read more
DDD and MVC: Difference between ‘Model’ and ‘Entity’
Entity Entity means an object that is a single item that the business logic works with, more specifically those which have an identity of some sort. Thus, many people refer to ORM-mapped objects as entities. Some refer to as “entity” to a class an instance of which represents a single row in a database. Some … Read more
What’s the HTML character entity for the # sign?
You can search it on the individual character at fileformat.info. Enter # as search string and the 1st hit will lead you to U+0023. Scroll a bit down to the 2nd table, Encodings, you’ll see under each the following entries: HTML Entity (decimal) # HTML Entity (hex) #
Should I write equals() and hashCode() methods in JPA entities?
Not necessarily. There are three options: don’t override – thus you will be working with instances. This is fine in cases when you are working with the collections with only entities that are attached to the session (and hence guaranteed to be the same instance). This is (for me) the preferred way in many cases, … Read more
How can I disable migration in Entity Framework 6.0
You can put this inside your entityFramework section of the app.config: <contexts> <context type=”YourNamespace.YourDbContext, YourAssemblyName” disableDatabaseInitialization=”true”/> </contexts> This msdn page tells all about the Entity Framework Configuration Section.
Differentiating between domain, model, and entity with respect to MVC
The terms are a bit vague I agree. I would use domain to refer to the business area you are dealing with. Like banking or insurance or what not. Then you have domain models. These are the things you deal with in that business domain, like for domain of banking you have accounts, customers, transfers … Read more
Entity Framework – Is there a way to automatically eager-load child entities without Include()?
No you cannot do that in mapping. Typical workaround is simple extension method: public static IQueryable<Car> BuildCar(this IQueryable<Car> query) { return query.Include(x => x.Wheels) .Include(x => x.Doors) .Include(x => x.Engine) .Include(x => x.Bumper) .Include(x => x.Windows); } Now every time you want to query Car with all relations you will just do: var query = … Read more
Difference between Entity and DTO
Short answer: Entities may be part of a business domain. Thus, they can implement behavior and be applied to different use cases within the domain. DTOs are used only to transfer data from one process or context to another. As such, they are without behavior – except for very basic and usually standardised storage and … Read more