测试样例executeryQuery方法

Question

我一直在用spock和grails进行测试，但是遇到了以下问题。我试图对HQL语句进行如下简单测试：

@Transactional
class UserService {
    List<User> getAll() {
        List<User> lUser = User.executeQuery('Select u.age from User u')
        return  lUser
    }
}

为此，我使用了以下测试：

@Mock(User)
@TestFor(UserService)
class UserServiceSpec extends Specification {
    void "test service"() {
        when:
        def res = service.getAll()
        then:
        assert true
    }
}

执行它时，出现以下错误。

java.lang.UnsupportedOperationException: String-based queries like [executeQuery] are currently not supported in this implementation of GORM. Use criteria instead.

    at org.grails.datastore.gorm.GormStaticApi.unsupported(GormStaticApi.groovy:880)
    at org.grails.datastore.gorm.GormStaticApi.executeQuery(GormStaticApi.groovy:800)
    at test.UserService.getAll(UserService.groovy:9)
    at test.UserServiceSpec.test service(UserServiceSpec.groovy:16)

有人知道如何在不使用条件的情况下解决问题吗？

PD：我正在使用grails 2.3.6和Hibernate 3.6.10.8