JPQL Constructor Expression case when Enum Literal

[Markus Schmider]

Hello,

is it possible to use Enum Literals in a case when Expression?

SELECT new de.rupp.entity.BookCategory(
    b.name, 
    case when b.pages > 200 then de.rupp.entity.Category.THICK else de.rupp.entity.Category.THIN end) 
FROM Book b

is not valid (Wildfly 8.1 refuses to deploy the war)

public class BookCategory {
	
	private String name;
	private Category category;
	
	
	
	public BookCategory(String name, Category category) {
		super();
		this.name = name;
		this.category = category;
	}
	
}

public enum Category {
	
	THICK, THIN

}

[Roel De Nijs]

Markus Schmider wrote:is not valid (Wildfly 8.1 refuses to deploy the war)

And which error / stack trace do you get?

[Michal Sam]

Yes, six years later but if someone still need a solution then:
- use Enum value as param in JPQL query
- CAST a result of CASE to desired enum class

so for this case:

SELECT new de.rupp.entity.BookCategory(
    b.name, 
    CAST (case when b.pages > 200 then :THICK else :THIN end as de.rupp.entity.Category) 
FROM Book b

and somwhere in code set parameters as:

            query.setParameter("THICK", Category.THICK );
            query.setParameter("THIN", Category.THIN );

[Campbell Ritchie]

MS, welcome to the Ranch

Yes, sometimes people go back to such old discussions and if so, they would find your solution useful.