HQL：两个位置之间的距离计算？

Question

I have a table Restaurants which stores the details of restaurants including Latitude and Longitude .now i have to sort out the records from DB those within 20 Kilo Meter of the given Lat/Lon input values.

I am using RESTful web-service with hibernate.

Entity Class

@Entity
@Table(name = "restaurants")
public class Restaurants implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "restaurant_id")
    private int restaurantId;

    @Column(name = "restaurant_name")
    private String restaurantName;

    @Column(name = "category_id")
    private Integer categoryId;

    @Column(name = "image_url")
    private String imageUrl;

    private Float longitude;

    private Float latitude;

    @Column(name = "contact_name")
    private String contactName;

    @Column(name = "primary_phone")
    private String primaryPhone;

    @Column(name = "secondary_phone")
    private String secondaryPhone;

    private String fax;

    private String address1;

    private String address2;

    //Getters and Setters

} 

I have surfed but couldn't find any satisfying answer.is it preferable between operation to find out the difference between Lat/Long .or do i use Criteria ? Any one please provide me an answer .?

Answer 1

Maybe you choose use Hibernate Spatial ?

You can find a tutorial here: http://www.hibernatespatial.org/documentation/02-Tutorial/01-tutorial4/

Becareful all database doesn't support Hibernate Spatial. You can check your database support here: http://www.hibernatespatial.org/documentation/03-dialects/01-overview/

Also becareful to change your SQLDialect