Sprin JPA如何获取列的AVG

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import import javax.persistence.Id;

@Entity
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column
    private Integer value;

    // 省略getter和setter方法
}

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;

public interface MyEntityRepository extends JpaRepository<MyEntity, Long> {

    @Query("SELECT AVG(e.value) FROM MyEntity e")
    Double getAverageValue();
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class MyService {

    private final MyEntityRepository repository;

    @Autowired
    public MyService(MyEntityRepository repository) {
        this.repository = repository;
    }

    public Double getAverageValue() {
        return repository.getAverageValue();
    }
}