问题
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?
回答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.
回答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"
来源：https://stackoverflow.com/questions/5584038/java-hibernate-selecting-the-discriminator-column-in-polymorphic-hql-query