The discriminator column contains marker values that tell the persistence layer what subclass to instantiate for a particular row. A restricted set of types may be used: String, Char, Int32, Byte, Short, Boolean, YesNo, TrueFalse.

What is discriminator in NHibernate?

The discriminator column contains marker values that tell the persistence layer what subclass to instantiate for a particular row. A restricted set of types may be used: String, Char, Int32, Byte, Short, Boolean, YesNo, TrueFalse.

What is NHibernate mapping?

nhibernate Mappings Xml Mappings It is a syntax xml file which contains the metadata required for the object/relational mapping. The metadata includes declaration of persistent classes and the mapping of properties (to columns and foreign key relationships to other entities) to database tables.

How do you use NHibernate?

Welcome to NHibernate

  1. Installing NHibernate.
  2. Defining a simple business object class.
  3. Create an NHibernate mapping to load and save the business object.
  4. Configure NHibernate to talk to your local database.
  5. Automatically generate a database.
  6. Writing simple CRUD code using the Repository pattern.

What inheritance mapping strategies are available in hibernate?

There are three inheritance mapping strategies defined in the hibernate:

  • Table Per Hierarchy.
  • Table Per Concrete class.
  • Table Per Subclass.

What is discriminator value in hibernate?

In case of table per class hierarchy an discriminator column is added by the hibernate framework that specifies the type of the record. It is mainly used to distinguish the record. To specify this, discriminator subelement of class must be specified. The subclass subelement of class, specifies the subclass.

How does hibernate inheritance work?

Hibernate Inheritance Mapping

  1. Entity inheritance means that we can use polymorphic queries for retrieving all the subclass entities when querying for a superclass.
  2. Notice that this class no longer has an @Entity annotation, as it won’t be persisted in the database by itself.

What is QueryOver?

Note: QueryOver is intended to remove the references to ‘magic strings’ from the ICriteria API while maintaining it’s opaqueness. It is not a LINQ provider; NHibernate has a built-in Linq provider for this.

Which is better NHibernate or entity framework?

nHibernate supports all types of databases but Entity framework need additional connectors to support databases other than MSSQL. nHibernate can be extended in terms of data loading, SQL generation, custom column types, custom collections etc but entity framework has limited extension points.

What is difference between hibernate and NHibernate?

are some of the popular companies that use Hibernate, whereas NHibernate is used by Pinnacle Sports, ProProcure, and CRM Solutions. Hibernate has a broader approval, being mentioned in 133 company stacks & 404 developers stacks; compared to NHibernate, which is listed in 6 company stacks and 5 developer stacks.

What is discriminator column in Hibernate?

Discriminator Values. Since the records for all entities will be in the same table, Hibernate needs a way to differentiate between them. By default, this is done through a discriminator column called DTYPE that has the name of the entity as a value.

What is discriminator column?

The discriminator column is always in the table of the base entity. It holds a different value for records of each class, allowing the JPA runtime to determine what class of object each row represents. The DiscriminatorColumn annotation represents a discriminator column.