fix: @query with projection and List<List>

data-hibernate-jpa/src/test/groovy/io/micronaut/data/hibernate/querygroupby/TaskRepositorySpec.groovy

@@ -0,0 +1,99 @@
+package io.micronaut.data.hibernate.querygroupby
+
+import io.micronaut.context.annotation.Property
+import io.micronaut.data.hibernate.entities.MicronautProject
+import io.micronaut.data.hibernate.entities.MicronautTask
+import io.micronaut.test.extensions.spock.annotation.MicronautTest
+import jakarta.inject.Inject
+import spock.lang.PendingFeature
+import spock.lang.Specification
+
+import java.time.LocalDate
+
+@MicronautTest(startApplication = false, packages = "io.micronaut.data.hibernate.entities")
+@Property(name = "datasources.default.name", value = "mydb")
+@Property(name = 'jpa.default.properties.hibernate.hbm2ddl.auto', value = 'create-drop')
+class TaskRepositorySpec extends Specification {
+
+    @Inject
+    MicronautProjectRepository projectRepository
+
+    @Inject
+    MicronautTaskRepository taskRepository
+
+    @PendingFeature
+    void "@Query projecting to a POJO"() {
+        given:
+        MicronautProject p1 = projectRepository.save(new MicronautProject("P1", "Project 1", "Description of Project 1"))
+        MicronautProject p2 = projectRepository.save(new MicronautProject("P2", "Project 2", "Description of Project 2"))
+        MicronautProject p3 = projectRepository.save(new MicronautProject("P3", "Project 3", "Description of Project 3"))
+        MicronautTask t1 = taskRepository.save(new MicronautTask("Task 1", "Task 1 Description", LocalDate.of(2025, 1, 12), p1, TaskStatus.TO_DO))
+        MicronautTask t2 = taskRepository.save(new MicronautTask("Task 2", "Task 2 Description", LocalDate.of(2025, 2, 10), p1, TaskStatus.TO_DO))
+        MicronautTask t3 = taskRepository.save(new MicronautTask("Task 3", "Task 3 Description", LocalDate.of(2025, 3, 16), p1, TaskStatus.TO_DO))
+        MicronautTask t4 = taskRepository.save(new MicronautTask("Task 4", "Task 4 Description", LocalDate.of(2025, 6, 25), p1, TaskStatus.IN_PROGRESS))
+
+        expect:
+        3 == countIterableElements(projectRepository.findAll())
+
+        4 == countIterableElements(taskRepository.findAll())
+
+        when:
+        Iterable<TasksPerYear> tasks = taskRepository.countByDueYear()
+
+        then:
+        2 == countIterableElements(tasks)
+
+        cleanup:
+        taskRepository.delete(t4)
+        taskRepository.delete(t3)
+        taskRepository.delete(t2)
+        taskRepository.delete(t1)
+        projectRepository.delete(p3)
+        projectRepository.delete(p2)
+        projectRepository.delete(p1)
+    }
+
+    @PendingFeature
+    void "@Query returning List of List"() {
+        given:
+        MicronautProject p1 = projectRepository.save(new MicronautProject("P1", "Project 1", "Description of Project 1"))
+        MicronautProject p2 = projectRepository.save(new MicronautProject("P2", "Project 2", "Description of Project 2"))
+        MicronautProject p3 = projectRepository.save(new MicronautProject("P3", "Project 3", "Description of Project 3"))
+        MicronautTask t1 = taskRepository.save(new MicronautTask("Task 1", "Task 1 Description", LocalDate.of(2025, 1, 12), p1, TaskStatus.TO_DO))
+        MicronautTask t2 = taskRepository.save(new MicronautTask("Task 2", "Task 2 Description", LocalDate.of(2025, 2, 10), p1, TaskStatus.TO_DO))
+        MicronautTask t3 = taskRepository.save(new MicronautTask("Task 3", "Task 3 Description", LocalDate.of(2025, 3, 16), p1, TaskStatus.TO_DO))
+        MicronautTask t4 = taskRepository.save(new MicronautTask("Task 4", "Task 4 Description", LocalDate.of(2025, 6, 25), p1, TaskStatus.IN_PROGRESS))
+
+        expect:
+        3 == countIterableElements(projectRepository.findAll())
+
+        4 == countIterableElements(taskRepository.findAll())
+        when:
+        List<List<Integer>> tasks = taskRepository.countByDueYearReturnList()
+
+        then:
+        2 == tasks.size()
+        tasks.every { it.size()  == 2 }
+
+        cleanup:
+        taskRepository.delete(t4)
+        taskRepository.delete(t3)
+        taskRepository.delete(t2)
+        taskRepository.delete(t1)
+        projectRepository.delete(p3)
+        projectRepository.delete(p2)
+        projectRepository.delete(p1)
+    }
+
+    static int countIterableElements(Iterable<?> iterable) {
+        int count = 0
+        Iterator<?> iterator = iterable.iterator()
+        if (iterator.hasNext()) {
+            do {
+                iterator.next()
+                count++
+            } while (iterator.hasNext())
+        }
+        count
+    }
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/entities/MicronautProject.java

@@ -0,0 +1,101 @@
+package io.micronaut.data.hibernate.entities;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import java.util.HashSet;
+import java.util.Objects;
+import java.util.Set;
+
+@Entity
+public class MicronautProject {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(unique = true, nullable = false, updatable = false)
+    private String code;
+    private String name;
+    private String description;
+    @OneToMany(mappedBy = "project", orphanRemoval = true, fetch = FetchType.EAGER, cascade = CascadeType.ALL)
+    private Set<MicronautTask> tasks = new HashSet<>();
+    public MicronautProject() {
+    }
+
+    public MicronautProject(String code, String name, String description) {
+        this.code = code;
+        this.name = name;
+        this.description = description;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(code);
+    }
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        MicronautProject other = (MicronautProject) obj;
+        if (code == null) {
+            if (other.code != null)
+                return false;
+        } else if (!code.equals(other.code))
+            return false;
+        return true;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public Set<MicronautTask> getTasks() {
+        return tasks;
+    }
+
+    public void setTasks(Set<MicronautTask> tasks) {
+        this.tasks = tasks;
+    }
+
+    @Override
+    public String toString() {
+        return "Project [id=" + id + ", code=" + code + ", name=" + name + ", description=" + description + "]";
+    }
+
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/entities/MicronautTask.java

@@ -0,0 +1,130 @@
+package io.micronaut.data.hibernate.entities;
+
+import io.micronaut.data.hibernate.querygroupby.TaskStatus;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+import java.time.LocalDate;
+import java.util.Objects;
+import java.util.UUID;
+
+@Entity
+public class MicronautTask {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(unique = true, nullable = false, updatable = false)
+    private String uuid = UUID.randomUUID().toString();
+    private String name;
+    private String description;
+    private LocalDate dueDate;
+
+    private TaskStatus status;
+
+    @ManyToOne(optional = false)
+    private MicronautProject project;
+
+
+    public MicronautTask() {
+    }
+    public MicronautTask(String name, String description, LocalDate dueDate, MicronautProject project) {
+        this(name, description, dueDate, project, TaskStatus.TO_DO);
+    }
+
+    public MicronautTask(String name, String description, LocalDate dueDate, MicronautProject project, TaskStatus status) {
+        this.name = name;
+        this.description = description;
+        this.dueDate = dueDate;
+        this.status = status;
+        this.project = project;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj)
+            return true;
+        if (obj == null)
+            return false;
+        if (getClass() != obj.getClass())
+            return false;
+        MicronautTask other = (MicronautTask) obj;
+        if (uuid == null) {
+            if (other.uuid != null)
+                return false;
+        } else if (!uuid.equals(other.uuid))
+            return false;
+        return true;
+    }
+    @Override
+    public int hashCode() {
+        return Objects.hash(uuid);
+    }
+
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getUuid() {
+        return uuid;
+    }
+
+    public void setUuid(String uuid) {
+        this.uuid = uuid;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public LocalDate getDueDate() {
+        return dueDate;
+    }
+
+    public void setDueDate(LocalDate dueDate) {
+        this.dueDate = dueDate;
+    }
+
+    public TaskStatus getStatus() {
+        return status;
+    }
+
+    public void setStatus(TaskStatus status) {
+        this.status = status;
+    }
+
+    public MicronautProject getProject() {
+        return project;
+    }
+
+    public void setProject(MicronautProject project) {
+        this.project = project;
+    }
+
+
+    @Override
+    public String toString() {
+        return "Task [id=" + id + ", name=" + name + ", description=" + description + ", dueDate=" + dueDate + ", status=" + status + ", project=" + project + "]";
+    }
+
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/querygroupby/MicronautProjectRepository.java

@@ -0,0 +1,8 @@
+package io.micronaut.data.hibernate.querygroupby;
+
+import io.micronaut.data.annotation.Repository;
+import io.micronaut.data.hibernate.entities.MicronautProject;
+import io.micronaut.data.repository.CrudRepository;
+@Repository
+public interface MicronautProjectRepository extends CrudRepository<MicronautProject, Long> {
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/querygroupby/MicronautTaskRepository.java

@@ -0,0 +1,16 @@
+package io.micronaut.data.hibernate.querygroupby;
+
+import io.micronaut.data.annotation.Query;
+import io.micronaut.data.annotation.Repository;
+import io.micronaut.data.hibernate.entities.MicronautTask;
+import io.micronaut.data.repository.CrudRepository;
+
+import java.util.List;
+@Repository
+public interface MicronautTaskRepository extends CrudRepository<MicronautTask, Long> {
+    @Query("select count(*), year(t.dueDate) from MicronautTask t group by year(t.dueDate)")
+    Iterable<TasksPerYear> countByDueYear();
+
+    @Query("select count(*), year(t.dueDate) from MicronautTask t group by year(t.dueDate)")
+    List<List<Integer>> countByDueYearReturnList();
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/querygroupby/TaskStatus.java

@@ -0,0 +1,16 @@
+package io.micronaut.data.hibernate.querygroupby;
+
+public enum TaskStatus {
+    TO_DO("To Do"),
+    IN_PROGRESS("In Progress"),
+    ON_HOLD("On Hold"),
+    DONE("Done");
+    private final String label;
+
+    private TaskStatus(String label) {
+        this.label = label;
+    }
+    public String getLabel() {
+        return label;
+    }
+}

data-hibernate-jpa/src/test/java/io/micronaut/data/hibernate/querygroupby/TasksPerYear.java

@@ -0,0 +1,22 @@
+package io.micronaut.data.hibernate.querygroupby;
+
+import io.micronaut.core.annotation.Introspected;
+
+@Introspected
+public class TasksPerYear {
+    private final String number;
+    private final String year;
+
+    public TasksPerYear(String number, String year) {
+        this.number = number;
+        this.year = year;
+    }
+
+    public String getNumber() {
+        return number;
+    }
+
+    public String getYear() {
+        return year;
+    }
+}