使用Date属性创建自定义spring JPA查询

Question

This is my first Java Spring project ever. I'm using PostgreSQL to store a WorkedDay entity as follows:

@Entity
@Table
public class WorkedDay {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date weekDay;

    @Column
    private Long employeeId;

    @ManyToOne
    @PrimaryKeyJoinColumn(name = "employeeId", referencedColumnName = "id")
    private Employee employee;

    @OneToMany
    private List<WorkedHours> workedHours = new ArrayList<>();
}

All "WorkedDays" are stored in a PostgreSQL table using a WorkedDayRepository class that extends CrudRepository . I'm also creating a report service which should return a list of WorkedDays in a given month.

public class WorkedDayRepositoryImpl implements WorkedDayRepositoryCustom {

    public List<WorkedDay> getReportByMonthValue(int monthValue) {
        //service code implementation here
    }
}

I'm currently facing problems creating this custom query, since I need to retrieve from the table all Date weekDay attributes with a specific month, passed as argument.

I'm inexperienced with Spring JPA. Is there a better(or simpler) way to do this? I tried to use Specifications and Querydsl but failed.

Answer 1

This should work

@Repository
public interface WorkedDayRepository extends CrudRepository<WorkedDay> {

   List<WorkedDay> findByWeekDay_Month(int month)

}

Answer 2

You could try @Query in combination with the MONTH Function.

@Repository
public interface WorkedDayRepository extends CrudRepository<WorkedDay> {

   @Query("select w from WorkedDay w where MONTH(w.weekDay) = ?1")
   List<WorkedDay> findByWeekDay(int month)

}

Keep in mind that not all databases might support MONTH(). Otherwise you could work with SUBSTRING(w.weekDay,6,7)