I have two tables: Organization(Parent) and Department(Child).
There is One to Many relationship, and is mentioned in Organization table only.
#Entity
#Table(name="TBL_STD_ORGANIZATION")
public class Organization implements Serializable {
#Id
#GeneratedValue
#Column(name="FLD_ORG_ID")
private Long organizationId;
#Column(name="FLD_ORG_NAME")
private String orgName;
#OneToMany(cascade=CascadeType.ALL,fetch=FetchType.EAGER)
private java.util.List<Department> listOfDepartMents = new java.util.ArrayList<Department>();
}
Below is Department Class:
#Entity
#Table(name="TBL_STD_DEPARTMENT")
public class Department implements Serializable {
#Id
#GeneratedValue
#Column(name = "FLD_DEPARTMENT_ID")
private Long departmentId;
#Column(name = "FLD_DEPARTMENT_NAME")
private String departmentName;
}
I wrote relationship in Parent table, because of it hibernate creates third table.
Now, I have to retrieve departments start with "sa" keyword and in specific organization.
So I want the HQL or SQL query query. I am not getting it how to write such complex query.
Any suggestions?
I'm fairly certain the HQL/JPQL would be:
SELECT d FROM Organization o JOIN o.listOfDepartMents d WHERE d.departmentName LIKE "sa%"
Related
I have a two table Company and CompanyRepo like below
COMAPNY
COMPANY_REPO
I have entities for those two tables like this :
#Entity
#Table(name="COMAPNY")
public class Company implements Serializable {
#Id
#Column(name="COMPANY_ID")
private Long companyId;
#Column
private String companyName;
#OneToMany(mappedBy="COMPANY")
private List<CompanyRepo> companyRepo;
}
#Entity
#Table(name="COMAPNY_REPO")
public class CompanyRepo implements Serializable {
#Id
#Column(name="COMPANY_REPO_ID")
private Long companyRepoId;
#Column
private String COMPANY_ID;
#Column
private String DEPT_ID;
#ManyToOne
#JoinColumn(name="COMPANY_ID")
private Company company;
}
Now i want to execute below query using a Hibernate relationship mapping
select Company_name from company as C ,company_repo as cr where c.company_id=cr.company_id and dept_id=10
I wrote a JPA repository like below by using a #OneToMany in Company table and #ManyToOne in CompanyRepo. But in resultant I am getting multiple COMPANYobject inside COMPANY_REPO Object.Does my relationship mapping is correct ?
public interface CompanyRepository extends JpaRepository<CompanyRepo, Long> {
public CompanyRepo findByDeptId(Long deptId);
}
Given your current database design, try something such as the following:
public interface CompanyRepository extends JpaRepository<Company, Long> {
#Query(value="SELECT * from company as C WHERE c.company_id = (SELECT cr.company_id FROM company_repo as cr WHERE cr.dept_id = ?1)", nativeQuery=true)
public Company findByDeptId(Long deptId);
}
The #Query annotation is a very powerful and flexible way to define methods in Repository interface. If you need more complex logic, I would recommend reading about the use and possibilities of the annotation. See here.
Based on your entity class your have multiple
COMPANY_ID that is not a proper way to declare your column name.
#Column
private String COMPANY_ID;
#ManyToOne
#JoinColumn(name="COMPANY_ID")
private Company company;
So please change your #Column
private String COMPANY_ID; to #Column("comp_id)
private String companyId;
If you want to get the CompanyRepo based on Company type then you need to change your query to fetch the dept id.
And your #Column
private String DEPT_ID; is String datatype so pass String to your repository.
#Query(" select companyRepo.company from CompanyRepo as companyRepo where companyRepo.DEPT_ID = :deptId")
public Company findByDeptId(String deptId);
I am trying to use hibernate annotations for getting data from a MySQL database table which doesn't have a primary key defined.
However the fact is 2 columns of that table together are unique in the table. How can I achieve the same using hibernate annotation?
This is my code
#Entity
#Table(name = "coc_order_view")
public class CoCOrderDetailsTest {
#EmbeddedId
private MyJoinClassKey key;
#Column(name = "coupon_code")
private String couponCode;
some other columns and their getters and setters .....
#Embeddable
public class MyJoinClassKey implements Serializable {
private static final long serialVersionUID = -5L;
#Column(name = "product_id")
private int productId;
#Column(name = "order_id")
private int orderId;
gettes and setters....
And here is my criteria query
Criteria criteria = getHibernatetemplate().getSession().createCriteria(CoCOrderDetailsTest.class);
criteria.add(Restrictions.eq("status", "New"));
ArrayList<CoCOrderDetailsTest> orderDet = (ArrayList<CoCOrderDetailsTest>) getHibernatetemplate().get(criteria);
I am unable to get all the values from db. Kindly suggest some solutions.
After reading through your question again not sure this will help. You can't have a table without primary key(s). Read the first couple of paragraphs in this article
That said, if you can alter the table and add primary keys on those fields you need to add #IdClass annotation to your class signature for CoCOrderDetailsTest and then get rid of the #embeddable and #embeddedId notation in your classes.
Another alternative, if you can add a field to the table, would be to use an #GeneratedValue on that added primary key field and of course annotate it with #Id.
If you can't alter the table then you can't use JPA and you'll have to use JDBC.
See http://docs.oracle.com/javaee/5/api/javax/persistence/IdClass.html
A working example:
#Entity
#Table(name = "player_game_log")
#IdClass(PlayerGameLogId.class)
public class PlayerGameLog {
#Id
#Column(name = "PLAYER_ID")
private Integer playerId;
#Id
#Column(name = "GAME_ID")
private String gameId;
....
and the id class (note there are no annotations on the id class)....
public class PlayerGameLogId implements Serializable {
private static final long serialVersionUID = 1L;
private Integer playerId;
private String gameId;
Try:
String hql = "FROM CoCOrderDetailsTest WHERE status = :status";
Query query = session.createQuery(hql);
query.setParameter("status","New");
List results = query.list();
I usually use EntityManager rather than session so I'm not familiar with this syntax - and I have typically added a type to the list to be returned - like:
List<CoCOrderDetailsTest> results = query.list();
Assuming theses Entities
#Entity
public class EntityNote implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#SequenceGenerator(name="SeqEntityNote", sequenceName="SeqEntityNote", allocationSize = 1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SeqEntityNote")
private long id;
private Date date;
private String subject;
private String content;
#ManyToMany
private List<EntityTopic> listEntityTopic;
//setters/getters
#Entity
public class EntityTopic implements Serializable {
#Id
#SequenceGenerator(name="SeqEntityTopic", sequenceName="SeqEntityTopic", allocationSize = 1)
#GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SeqEntityTopic")
private long id;
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
In my DB, a join table named "entity_note_list_entity_topic" records the ManyToMany relation.
This works correctly so far.
But I'd like to perform a count query like 'how many EntityNotes per EntitityTopic'
Unfortunatly I'm quite lost in this situation.
How this query can be written ?
Do I need other elements in my two entities ?
(In many examples I see a reverse relation using mappedBy attribute on ManyToMany.. Do I need this ?)
It will be the easiest if you make the many to many relation bidirectional. There are no serious extra costs involved, as it uses the same db structure, and the list are lazy loaded so if the relation is not being used the lists are not populated (you can hide the second direction by making accessors private).
Simply change:
#Entity
public class EntityTopic implements Serializable {
...
#ManyToMany(mappedBy="listEntityTopic")
private List<EntityNote> notes;
}
You can issue normal count jpql queries, for example:
SELECT count(n) from EntityTopic t INNER JOIN t.notes n where t.name =:name
so you don't neet to retrieve the notes and topics if don't need to.
But I also believe that your original mapping can also be queries with:
SELECT COUNT(n) FROM EntityNote n INNER JOIN n.listEntityTopic t WHERE t.name = :name
If you have the following code:
#Entity
public class EntityNote implements Serializable {
#ManyToMany(fetch = FetchType.LAZY)
private List<EntityTopic> topics;
}
#Entity
public class EntityTopic implements Serializable {
#ManyToMany(fetch = FetchType.LAZY)
private List<EntityNote> notes;
}
Then, topic.getNotes().size() will give you the number of notes associated with a topic. When using Hibernate as the JPA provider, a SELECT COUNT(...) query is issued for this instead of loading all the associated notes. If this does not work for you out-of-the-box, mark the collections as extra lazy using the instructions in this post.
I have next classes:
#Entity
#Table(name="A")
public class A implements Serializable{
#Id
#Column(name="a_id")
private long aId;
#ManyToOne
#JoinColumn(name="b_id")
private B b;
}
#Entity
#Table(name="b")
public class B implements Serializable{
#Id
#Column(name="b_id")
private long bId;
#Column(name="b_name")
private String name;
#Column(name="b_age")
private String age;
#OneToMany(mappedBy="b")
private Set<A> a;
}
I have getters and setters for this classes.
when I try execute next Criteria
session.createCriteria(A.class, "a_table")
.createAlias("a_table.b", "b_table")
.add(Restrictions.eq("b_table.age", "11"))
.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY)
.list();
In SQL generated by hibernate I have all fields from B (I mean field "name" too).
How I can make to Hibernate bring only needed fields.
In case that in criteria exists many aliases to many tables, it can increase execution time.
Thank you.
Try using projections. Maybe something like this:
Criteria cr = session.createCriteria(User.class)
.setProjection(Projections.projectionList()
.add(Projections.property("id"), "id")
.add(Projections.property("Name"), "Name"))
.setResultTransformer(Transformers.aliasToBean(User.class));
List list = cr.list();
I am using Sprind JPA, Spring 3.1.2(in future 3.2.3), Hibernate 4.1 final.
I am new to Sprind Data JPA. I have tow Table Release_date_type and Cache_media which entities are as follows :
ReleaseAirDate.java
#Entity
#Table(name = "Release_date_type")
public class ReleaseDateType {
#Id
#GeneratedValue(strategy=GenerationType.TABLE)
private Integer release_date_type_id;
#Column
private Integer sort_order;
#Column
private String description;
#Column
private String data_source_type;
#Column(nullable = true)
private Integer media_Id;
#Column
private String source_system; with getters and setters..
and CacheMedia as
#Entity
#Table(name = "Cache_Media")
public class CacheMedia {
#Id
#GeneratedValue(strategy=GenerationType.TABLE)
private Integer id;
#Column(name="code")
private String code;
#Column(name="POSITION")
private Integer position;
#Column(name="DESCRIPTION")
private String media_Description; with setter and getters.
Now my repository interface is as follows :
public interface ReleaseDateTypeRepository extends CrudRepository<ReleaseDateType, Long>{ }
Now i want to write a method(Query) in ReleaseDateTypeRepository interface which can get all the data from Release_Date_Type table including appropriate media_description from Table 'Cache_Media' based on media_id of Release_date_type table.
So my select (SQL)query looks like
SELECT * from Release_Date_Type r left join Cache_Media c on r.media_id=c.id
I don't know how to map entities.
I tried so many thing but not luck.
Any help is appreciated.
Its not the answer for joining via Hibernate, but alternatively you can create a view with your join and map the view to your objects