SubSonic is not as extensive as nHibernate; rather, it is a straight forward Active Record 1 class per table Data Access Layer. Some of the features are a query tool, ability to execute stored procedures and a scaffolding app in ASP.net. You can be up and running within 30 minutes or less, with a tiny … Read more
I tend towards first approach for all the usual reasons of normalisation. This approach also makes it easier to perform data cleansing on mailing details. If you are possibly going to allow multiple addresses (mail, residential, etc) or wish to be able to use effective dates, consider this approach Customer (id, phys_address_id) Cust_address_type (cust_id, mail_address_id, … Read more
These Annotations are no creating two sequences, only one. Is this correct/expected? That’s the expected behavior. When using @GeneratedValue(strategy = GenerationType.AUTO), the JPA provider will pick an appropriate strategy for the particular database. In the case of Oracle, this will be SEQUENCE and, since you did not specify anything, Hibernate will use a single global … Read more
You are probably looking for select_related, which is the natural way to achieve this: pubs = publication.objects.select_related(‘country’, ‘country_state’, ‘city’) You can check the resulting SQL via str(pubs.query), which should result in output along the following lines (the example is from a postgres backend): SELECT “publication”.”id”, “publication”.”title”, …, “country”.”country_name”, … FROM “publication” INNER JOIN “country” ON … Read more
I’ve been working with django for a while now and I have had a pretty rough time figuring out the table joins, but I think I finally understand and I would like to pass this on to others so they may avoid the frustration that I had with it. Consider the following model.py: class EventsMeetinglocation(models.Model): … Read more
You can create a simple stored procedure in SQL Server that selects the next sequence value like this: CREATE PROCEDURE dbo.GetNextSequenceValue AS BEGIN SELECT NEXT VALUE FOR dbo.TestSequence; END and then you can import that stored procedure into your EDMX model in Entity Framework, and call that stored procedure and fetch the sequence value like … Read more
If this small resume is true ? Yes. If it is true, what is the difference between eager and explicit loading? Eager loading is the opposite of Lazy loading but Explicit loading is similar to lazy loading, except that: you explicitly retrieve the related data in code; it doesn’t happen automatically when you access a … Read more
The syntax of your JPQL query is incorrect. Either use (with a positional parameter): List<Long> ids = Arrays.asList(380L, 382L, 386L); Query query = em.createQuery(“FROM TrackedItem item WHERE item.id IN (?1)”); query.setParameterList(1, ids) List<TrackedItem> items = query.getResultList(); Or (with a named parameter): List<Long> ids = Arrays.asList(380L, 382L, 386L); Query query = em.createQuery(“FROM TrackedItem item WHERE item.id … Read more
Django 1.4 provides a bulk_create() method on the QuerySet object, see: https://docs.djangoproject.com/en/dev/ref/models/querysets/#django.db.models.query.QuerySet.bulk_create https://docs.djangoproject.com/en/dev/releases/1.4/ https://code.djangoproject.com/ticket/7596
You can use a JPA converter to map your Entity to the database. Just add an annotation similar to this one to your params field: @Convert(converter = JpaConverterJson.class) and then create the class in a similar way (this converts a generic Object, you may want to specialize it): @Converter(autoApply = true) public class JpaConverterJson implements … Read more