java hibernate: selecting the discriminator column in polymorphic hql query

Question

In hibernate, I want to select the discriminator value. Something like

select discriminator, id, name, age from Animal

The idea is to send the result of this query to the client side, so that I can display a different icon based on the value of the discriminator column (i.e. cat, dog, elephant, etc).

Is that possible? How?

Solution 1

You can do it as follows:

select a.class, a.id, a.name, a.age from Animal a

From Hibernate Documentation:

The special property class accesses the discriminator value of an instance in the case of polymorphic persistence.

Solution 2

Hibernate query objects, does not know columns. So unless you have a property named discriminator in your Animal object you cant do that. You can do the query in sql or get the entire object and then to get the inherited type, for that you can use "instanceof"

Comments

[flybywire]

Great! At first it did not work because I did not qualify with a. and wrote select class ...