How to query on Mapping Tables in Hibernate HQL

[Deepaks Deshpande]

Dear All,

I have the following classes

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

	/**
	 * 
	 */
	private static final long serialVersionUID = 6124429868637268214L;

	@Id
	@Column(name = "advertisementid", nullable = false)
	private int advertisementId;
	
	@Column(name = "advertisementtitle", nullable = false)
	private String advertisementTitle;
	
	@Column(name="startdate", nullable = false)
	@Type(type = "org.hibernate.type.TimestampType")
	private Date startDate;
	
	@Column(name = "enddate", nullable = false)
	@Type(type = "org.hibernate.type.TimestampType")
	private Date endDate;
	
	@Column(name = "advertisementdetails", nullable = false)
	@Type(type = "org.hibernate.type.TextType")
	private String advertisementDetails;
	
	@Column(name = "publishedstatus", nullable = false)
	@Type(type = "org.hibernate.type.NumericBooleanType")
	private Boolean publishedStatus;
	
	@ManyToMany(cascade = { CascadeType.ALL })
	@JoinTable(name = "Advt_Desg_UserDetails_Mapping", joinColumns = { @JoinColumn(name = "advertisementid")},
	inverseJoinColumns = { @JoinColumn(name = "designationid") })
	private Set<Designation> designation = new HashSet<Designation>();
	
	@ManyToMany(cascade = {CascadeType.ALL})
	@JoinTable(name = "Advt_Desg_Exam_Mapping", joinColumns = {@JoinColumn(name = "advertisementid")},
	inverseJoinColumns = {@JoinColumn(name = "designationid")})
	private Set<Designation> designationForAdvt = new HashSet<Designation>();
	
	@ManyToMany(cascade = {CascadeType.ALL})
	@JoinTable(name = "Advt_Desg_Exam_Mapping", joinColumns = {@JoinColumn(name = "advertisementid")},
	inverseJoinColumns = {@JoinColumn(name = "examid")})
	private Set<Exam> exam = new HashSet<Exam>();
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "advertisementid")
	private Set<Answer> answerOption = new HashSet<Answer>();
	/**
	 * 
	 */
	public Advertisements() {
		// TODO Auto-generated constructor stub
	}
	
      //getters and setters	
	
}

Another class as follows:

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

	/**
	 * 
	 */
	private static final long serialVersionUID = 5192204852848047958L;

	@Id
	@Column(name = "designationid", nullable = false)
	private int designationId;
	
	@Column(name = "designationname", nullable = false)
	private String designationName;
	
	@Column(name = "designationdescription", nullable = false)
	private String designationDescription;
	
	@ManyToMany(mappedBy = "userDesignation")
	private Set<UserDetails> userDesignationDetails = new HashSet<UserDetails>();
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "advertisementid")
	private Set<Advertisements> advertisements = new HashSet<Advertisements>();
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "advertisementid")
	private Set<Advertisements> advertisementsForMapping = new HashSet<Advertisements>();
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "designationid")
	private Set<Answer> answerOption = new HashSet<Answer>();
	
	/**
	 * 
	 */
	public Designation() {
		// TODO Auto-generated constructor stub
	}

	/**
	 * @param designationId
	 * @param designationName
	 * @param designationDescription
	 * @param userDesignationDetails
	 * @param jobsApplied
	 */
	public Designation(int designationId, String designationName,
			String designationDescription,
			Set<UserDetails> userDesignationDetails, Set<Advertisements> advertisements, Set<Advertisements> advertisementsForMapping) {
		super();
		this.designationId = designationId;
		this.designationName = designationName;
		this.designationDescription = designationDescription;
		this.userDesignationDetails = userDesignationDetails;
		this.advertisements = advertisements;
		this.advertisementsForMapping = advertisementsForMapping;
	}

       //getters and setters

And Another class as follows:

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

	/**
	 * 
	 */
	private static final long serialVersionUID = 2035170424379800778L;

	@Id
	@Column(name="userdetailsid", nullable = false)
	private int userDetailsId;
	
	@Column(name = "name", nullable = false)
	private String name;
	
	@Column(name = "age", length = 2, nullable = false)
	private Integer age;
	
	@Column(name = "gender", nullable = false)
	@Type(type = "org.hibernate.type.NumericBooleanType")
	private Boolean gender;
	
	@Column(name = "emailid", nullable = false)
	private String emailId;
	
	@Column(name = "alternateemailid", nullable = false)
	private String altEmailId;
	
	@Column(name = "username", nullable = false)
	private String userName;
	
	@Column(name = "password", nullable = false)
	private String password;
	
	@Column(name = "userphoto", nullable = false)
	private String userPhoto;
	
	@Column(name="resume", nullable = false)
	@Type(type = "org.hibernate.type.TextType")
	private String resume;
	
	@Column(name = "presentaddress", nullable = false)
	private String presentAddress;
	
	@Column(name = "pincode", length = 6, nullable = false)
	@Type(type = "java.lang.Integer")
	private Integer pincode;
	
	@Column(name = "landlineno", nullable = false)
	private String landLineNo;
	
	@Column(name = "mobileno", length = 10, nullable = false)
	@Type(type = "java.lang.Long")
	private Long mobileNo;
	
	@Column(name = "registrationdate", nullable = false)
	@Type(type = "org.hibernate.type.TimestampType")
	private Date registrationDate;
	
	@ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE}, fetch = FetchType.LAZY )
	@JoinColumn(name = "userroleid", insertable=true, updatable=true, nullable = false)
	private UserRole userRole;
	
	@ManyToMany(cascade = { CascadeType.ALL })
	@JoinTable(name = "Advt_Desg_UserDetails_Mapping", joinColumns = { @JoinColumn(name = "userdetailsid")},
	inverseJoinColumns = { @JoinColumn(name = "designationid") })
	private Set<Designation> userDesignation;
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "userdetailsid")
	private Set<Exam> examid = new HashSet<Exam>();
	
	@OneToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
	@JoinColumn(name = "userdetailsid")
	private Set<Answer> answerOption = new HashSet<Answer>();


	/**
	 * 
	 */
	public UserDetails() {
		// TODO Auto-generated constructor stub
	}
	
	

	/**
	 * @param userDetailsId
	 * @param name
	 * @param age
	 * @param gender
	 * @param emailId
	 * @param altEmailId
	 * @param userName
	 * @param password
	 * @param userPhoto
	 * @param resume
	 * @param presentAddress
	 * @param pincode
	 * @param landLineNo
	 * @param mobileNo
	 * @param registrationDate
	 * @param userRole
	 * @param userDesignation
	 */
	public UserDetails(int userDetailsId, String name, Integer age,
			Boolean gender, String emailId, String altEmailId, String userName,
			String password, String userPhoto, String resume,
			String presentAddress, Integer pincode, String landLineNo,
			Long mobileNo, Date registrationDate, UserRole userRole,
			Set<Designation> userDesignation) {
		super();
		this.userDetailsId = userDetailsId;
		this.name = name;
		this.age = age;
		this.gender = gender;
		this.emailId = emailId;
		this.altEmailId = altEmailId;
		this.userName = userName;
		this.password = password;
		this.userPhoto = userPhoto;
		this.resume = resume;
		this.presentAddress = presentAddress;
		this.pincode = pincode;
		this.landLineNo = landLineNo;
		this.mobileNo = mobileNo;
		this.registrationDate = registrationDate;
		this.userRole = userRole;
		this.userDesignation = userDesignation;
	}

        //getters

The above 3 classes produce a mapping table called "Advt_Desg_UserDetails_Mapping". The "Advt_Desg_UserDetails_Mapping" table is as follows :

CREATE TABLE `Advt_Desg_UserDetails_Mapping` (
  `userdetailsid` int(11) NOT NULL,
  `designationid` int(11) NOT NULL,
  `advertisementid` int(11) NOT NULL,
  PRIMARY KEY (`advertisementid`,`designationid`),
  KEY `FK3C227BFA1CD8F459` (`advertisementid`),
  KEY `FK3C227BFA78330FDE` (`userdetailsid`),
  KEY `FK3C227BFADA3647BE` (`designationid`),
  CONSTRAINT `FK3C227BFADA3647BE` FOREIGN KEY (`designationid`) REFERENCES `Designation` (`designationid`),
  CONSTRAINT `FK3C227BFA1CD8F459` FOREIGN KEY (`advertisementid`) REFERENCES `Advertisements` (`advertisementid`),
  CONSTRAINT `FK3C227BFA78330FDE` FOREIGN KEY (`userdetailsid`) REFERENCES `UserDetails` (`userdetailsid`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Can some body now tell me how to execute a query on this mapping table produced from the above 3 Classes.