Problems with making a query when using Enum in entity

I have the following in a Question entity:

@NamedQuery(name = "Question.allApproved",
    query = "SELECT q FROM Question q WHERE q.status = 'APPROVED'")

and

@Enumerated(EnumType.STRING)
private Status status;

// usual accessors

I am getting this exception:

> Exception Description: Error compiling the query > [Question.countApproved: SELECT COUNT(q) FROM Question q WHERE q.status = 'APPROVED'], line 1, column 47: invalid enum equal > expression, cannot compare enum value of type > [myCompnay.application.Status] with a non enum value > of type [java.lang.String]. at > org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:501)

How do I fix this?

I think you should use your (fully qualified) Status enum instead of literal value, so something like this: (assuming your Status enum is in com.myexample package)

@NamedQuery(name = "Question.allApproved", 
            query = "SELECT q 
                     FROM Question q 
                     WHERE q.status = com.myexample.Status.APPROVED").

4 years since the initial post, there are some developments. Using spring 4 and Hibernate 4 it's now possible to 'trick' Hibernate using a SpEL expression. For example:

The enum:

package com.mycompany.enums

public enum Status {
    INITIAL, PENDING, REJECTED, APPROVED, SHIPPED, DELIVERED, COMPLETE;
}

Here's a wrapper class called 'Filter' which we'll pass to the repository filtering method.

package com.mycompany.enums

public class Filter implements Serializable {

    /** The id of the filtered item */
    private Integer id;
    /** The status of the filtered item */
    private Status status;
    // more filter criteria here...

    // getters, setters, equals(), hashCode() - omitted for brevity

    /**
     * Returns the name of the status constant or null if the status is null. This is used in the repositories to filter
     * queries by the status using a the SPEL (T) expression, taking advantage of the status qualified name. For example:
     * {@code :#{T(com.mycompany.enums.Status).#filter.statusName}}
     *
     * @return the status constant name or null if the status is null
     */
    public String getStatusName() {
        return null == status ? status : status.name();
    }

 }

Finally, in the repository, we can now use the Filter class as the single parameter and make the query translate what appears to be a mixture of literals and SpEL expressions to a Status object:

The repository:

package com.mycompany.repository

@Repository
public interface OrderRepository extends CrudRepository<Order, Integer> {

    @Query("SELECT o from Order o "
            + "WHERE o.id = COALESCE(:#{#filter.id},o.id) "
            + "AND o.status = COALESCE(:#{T(com.mycompany.enums.Status).#filter.statusName},o.status)")
    public List<Order> getFilteredOrders(@Param(value = "filter") Filter filter);
}

This works perfectly, but for some odd reason I haven't figured out yet, if you enable SQL debugging in Hibernate and turn on the binder logging, you'll not be able to see Hibernate binding this expression to query variables.

Please use below property in application.properties logging.level.org.hibernate.type.descriptor.sql.BasicBinder=TRACE