Please help me to get the criteria builder version of following sql for the below given entity class:
sql:
select u.userid from employee e inner join user u on e.userid=u.userid
inner join employee_project ep on ep.empId=e.empId
inner join ep.projectId=p.projectId where p.projectId in (?,?...);
And also this should be able to used as a sub query too.
#Entity
#Table(name="Employee")
public class Employee {
#Id
#GeneratedValue(strategy= GenerationType.AUTO)
private Long id;
#OneToOne(optional=false, cascade=CascadeType.ALL, orphanRemoval=true)
#JoinColumn(name="userId")
private User user;
#ManyToMany
#JoinTable(
name="Employee_Project",
joinColumns={ #JoinColumn(name="empId", referencedColumnName="empId") },
inverseJoinColumns={ #JoinColumn(name="prjId", referencedColumnName="prjId") }
)
private List<Project> project;
}
Related
I'm struggling to make a query that inner join 3 tables and have a where clause. It's like my where doesn't exist.
Here are my entities:
CarModel entity:
#Entity
#Table(name = "CARMODEL")
public class CarModel implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#OneToMany(mappedBy = "carModel")
private List<MyCars> myCars;
MyCars entity
#Entity
#Table(name = "MYCARS")
public class MyCars implements Serializable{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#ManyToOne
#JoinColumn(name = "CarModel_id")
private CarModel carModel= new CarModel();
#ManyToOne
#JoinColumn(name = "user_id")
private User user = new User();
User entity:
#Entity
#Table(name = "USER")
public class User implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
#OneToMany(mappedBy = "user")
private List<MyCars> myCars;
Here is the graphical representation of these three entities:
And here is one of the queries i have tried:
public List<CarModel> findMyCarsByUserId(long IdUser)
{
String requete = "SELECT DISTINCT cm\n" +
"FROM MyCars ms\n" +
" INNER JOIN CarModel cm INNER JOIN User u where u.id=2";
Query query = em.createQuery(requete);
//query.setParameter("iduser", IdUser);
List<CarModel> cars = null;
cars = (List<CarModel>) query.getResultList();
return cars;
}
So here I'm trying to get all the ModeleVehicule for a given user_id. But I keep having all the ModeleVehicule of the table, despite the where clause.
I have a mysql query working for what I want:
SELECT cm.marque,cm.modele, cm.motorisation, cm.anneeModele, cm.puissance
FROM carmodel cm
INNER JOIN mycars ms ON cm.ID = ms.ModeleVehicule_id
INNER JOIN user u ON ms.user_id = u.ID
WHERE ms.user_id = 1
What am I doing wrong ?
I have faced with issue trying to select for update row using Spring data with Hibernate as JPA implementation and Postgresql.
Suppose we have entities:A,B,C.
public class A{
#Id
private Long id;
#OneToMany(fetch = FetchType.EAGER)
private Set<B> bSet;
#OneToMany(fetch = FetchType.EAGER)
private Set<C> cSet;
}
Suppose we want to select A with all related B and C entities for update i.e. with locking row related to A table.
#Query(SELECT a FROM A a
LEFT JOIN FETCH a.bSet
LEFT JOIN FETCH a.cSet
WHERE a.id=?)
#Lock(LockModeType.PESSIMISTIC_WRITE)
public A selectAndLockA(Long Aid);
The query will look like
SELECT a.column1, ... from tableA a LEFT JOIN tableB b ... FOR UPDATE of a,c
FOR UPDATE of a,c
The query will try to lock two tables what leads to exception like :
org.postgresql.util.PSQLException: ERROR: FOR UPDATE cannot be applied to the nullable side of an outer join
What I try to archive is locking only first table "FOR UPDATE OF a"
Is it possible to configure somehow or tell Hibernate to lock only first table.
This is not supported by PostreSQL. If you do an outer SELECT nothing can prevent somebody from inserting a row into the LEFT JOINED table thereby modifiying the result set you are looking at (e.g. the columns would not be NULL anymore on a repeated read).
For a detailed explanantion see here
It's been a long time since question was created, but I have a similar problem and hope my answer will help somebody.
Suppose that we have this JPA entities:
#Entity
#Table(name = "card_transactions")
public class CardTransactionsEntity {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "card_trans_seq")
#SequenceGenerator(name = "card_trans_seq", sequenceName = "card_trans_seq")
private Long id;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumns({
#JoinColumn(name = "ofd_id", referencedColumnName = "ofd_id"),
#JoinColumn(name = "receipt_id", referencedColumnName = "receipt_id")})
private ReceiptsEntity receipt;
#Column
#Enumerated(EnumType.STRING)
private CardTransactionStatus requestStatus;
...
}
#Entity
#Table(name = "receipts")
public class ReceiptsEntity {
#EmbeddedId
private OfdReceiptId id;
...
}
#Embeddable
public class OfdReceiptId implements Serializable {
#Column(name = "ofd_id")
#Enumerated(EnumType.STRING)
private OfdId ofdId;
#Column(name = "receipt_id")
private String receiptId;
...
}
And we want select CardTransactionsEntity with fetched ReceiptsEntity for pessimistic update only CardTransactionsEntity. This can be done using Hibernate and Spring Data JPA repository as
public interface CardTransactionRepository extends JpaRepository<CardTransactionsEntity, Long> {
#Query("select ct from CardTransactionsEntity ct left join fetch ct.receipt r where ct.requestStatus = :requestStatus")
#Lock(value = LockModeType.PESSIMISTIC_WRITE)
#QueryHints(value = {
#QueryHint(name = "javax.persistence.lock.timeout", value = "-2"), // LockOptions.SKIP_LOCKED
#QueryHint(name = "org.hibernate.lockMode.r", value = "NONE") // "r" is alias for ct.receipt and will excluded from PESSIMISTIC_WRITE
})
List<CardTransactionsEntity> loadCardTransactions(#Param("requestStatus") CardTransactionStatus requestStatus, Pageable pageable);
}
This repository method will execute query like
SELECT ct.*, r.* from card_transactions ct LEFT OUTER JOIN receipts r ON ct.ofd_id = r.ofd_id and ct.receipt_id = r.receipt_id WHERE ct.request_status=? LIMIT ? FOR UPDATE OF ct SKIP LOCKED
You can bypass this error with joining the tables with FetchType.LAZY. This fetch type is the default one and it is not required to specify for #OneToMany joins.
public class A{
#Id
private Long id;
#OneToMany
private Set<B> bSet;
#OneToMany
private Set<C> cSet;
}
I have OneToOne tables/entities Person and Employee:
each employee has only one person and each person is attached to one and only one employee.
The generated query do tables join with "cross join" keyword while "inner join" would be more appropriate
#Entity
#Table(name="person")
#Data
public class Person implements Serializable {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="id_Person", unique=true, nullable=false)
private long id;
#Column(nullable=false, length=50)
private String name;
#Column(nullable=false, length=255)
private String EMail;
}
#Entity
#Table(name="employee")
#Data
public class Employee implements Serializable {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="id_Employee", unique=true, nullable=false)
private long id;
#Column(nullable=false, length=50)
private String numero;
#OneToOne(fetch = FetchType.EAGER, optional=false)
#JoinColumn(name="id_Employee")
private Person person;
}
Repository:
public interface EmployeeRepository extends CrudRepository {
#Query("SELECT e FROM Employee e WHERE LOWER(e.person.name) LIKE CONCAT(LOWER(:name),'%')")
List findByName(#Param("name") String name);
}
Here is thes generated queries:
select employee0_.id_Employee as id_Emplo1_0_, employee0_.department as departme2_0_
from employee employee0_
cross join person person1_
where employee0_.id_Employee=person1_.id_Person
and (lower(person1_.name) like concat(lower(?), '%'))
;
select person0_.id_Person as id_Perso1_2_0_, person0_.EMail as EMail2_2_0_, person0_.name as name3_2_0_
from person person0_
where person0_.id_Person=?
;
You have an error in the entity Employee, join column should be id_Person.
Apart from that, I'd recommend using Querydsl for a fine-grained control over your joins. Your query will look something like this:
query.from(employee).leftJoin(employee.person, person)
.where(person.name.lower().like(name.toLowerCase() + "%")).fetch();
How to invoke order by on a joined entity? I am trying to achieve the following with:
select * from person p inner join telephone t on p.id=t.person_id join sim s on s.id=t.sim_id order by s.name DESC
#Entity
public class Person implements Serializable{
#Id
private Long id;
#OneToMany(orphanRemoval = true, mappedBy = "person", fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
private List<Telephone> telephonesNumber;
#Entity
public class Telephone implements Serializable {
#Id
private String number;
#Id
#ManyToOne()
#JoinColumn(name = "person_id")
private Person person;
#Id
#ManyToOne(cascade = {})
#JoinColumn(name = "sim_id")
private Sim sim;
#Entity
public class Sim implements Serializable {
#Id
private Long id;
#Column(unique = true)
private String name;
I use specification interface, in this example sorting is on the field person.id and it works
public class PersonSpecification implements Specification<Person> {
#Override
public Predicate toPredicate(Root<Person> root, CriteriaQuery<?> query, CriteriaBuilder builder) {
List<Predicate> predicates = new ArrayList<>();
// there is many different conditions for example
// if(someCondition!=null) {
// predicates.add(builder.like(root.get("someProperty"), someValue));
// }
query.groupBy(root.get("id"));
//there I want to order by Sim.name i dont know how
query.orderBy(builder.asc(root.get("phone")));//this works
return builder.and((predicates.toArray(new Predicate[predicates.size()])));
}
I want to order by Sim.name but i dont know how.
In JPA specification you can use:
query.orderBy(builder.asc(root.join("telephonesNumber").get("sim").get("name")));
to sort by sim name.
For more details:
https://en.wikibooks.org/wiki/Java_Persistence/Querying#Joining.2C_querying_on_a_OneToMany_relationship
If you using JPA Query:
#Query("select s from Person p
join p.telephonesNumber t
join t.sim s order
by t.sim.id desc")
It will produce this:
select * from person p
inner join telephone t on p.id=t.person_id
inner join sim s on t.sim_id=s.id
order by t.sim_id desc
For more details:
https://github.com/abhilekhsingh041992/spring-boot-samples/blob/master/jpa/src/main/java/example/springboot/jpa/repository/PersonRepository.java
another way for that would be using Query method:
List<Telephone> findAllByOrderBySimIdAsc();
Look at this findAllByOrderBySimIdAsc
With the code before, you can get all rows from Telephone ordered by Sim Id.
I have implemented Joined, Multiple Table Inheritance.
There is a 'parent' table pois and two sub tables: xPois and yPois and in turn I have an abstract PoiDao class as well as a XPoiDao and a YPoiDao class extending PoiDao.
A poi may have multiple reservations but a reservation belongs to exactly one poi.
Named queries defined in the child table DAOs work well for attributes defined in the respective (direct) table hierarchy. The parent table has a foreign key relationship to another table named reservations (table reservations holds the foreign key of table pois). The problem is that the records from this reservations table get not fetched.
Running this SQL statement in MySql Workbench gets the desired resultset:
SELECT * FROM xPois pp
LEFT JOIN pois p ON pp.poiId = p.poiId
LEFT JOIN reservations r ON p.poiId = r.poiId
WHERE pp.xPoiId = '2011';
In Eclipse I can see {IndirectList: not instantiated} when I inspect the xDao instance in debug mode.
How can I get the records from this table being stored in the PoiDao using JPA?
public abstract class PoiDao implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="poiId")
private Integer poiId;
#OneToOne(optional=false, cascade=CascadeType.ALL)
#JoinColumn(name="addressId",insertable=true,
updatable=true, unique=true, nullable=false)
private AddressDao address;
#Embedded
private GeoLocationDao geoLocation;
#Convert("poiTypeConverter")
private ServiceTypeEnum poiType;
#Column(name="operator")
private String operator;
#Column(name="reservable")
private boolean reservable;
#OneToMany(orphanRemoval=true, cascade=CascadeType.ALL, fetch=FetchType.LAZY)
#JoinColumn(name="poiId", insertable=true, updatable=true)
private List<ReservationDao> existingReservations;
...
}
#Entity
#Table(name="xPois")
#DiscriminatorValue("X")
#NamedQueries({
#NamedQuery(name="XPoiDao.findAll", query="SELECT p FROM XPoiDao p"),
#NamedQuery(name="XPoiDao.findByXPoiId",
query="SELECT pp FROM XPoiDao pp LEFT JOIN PoiDao p ON pp.poiId = p.poiId "
+ "LEFT JOIN ReservationDao r ON p.poiId = r.poiId WHERE pp.xPoiId = :xPoiId")
})
#ObjectTypeConverters({
#ObjectTypeConverter (
name="xPoiStatusConverter",
dataType=java.lang.String.class, // type in DB
objectType=XPoiStatusEnum.class, // Java type
conversionValues={
#ConversionValue(dataValue="FREE", objectValue="FREE"),
#ConversionValue(dataValue="OCCUPIED BY VALUE", objectValue="OCCUPIED_BY_VALUE"),
#ConversionValue(dataValue="OCCUPIED MANUALLY", objectValue="OCCUPIED_MANUALLY"),
#ConversionValue(dataValue="BLOCKED", objectValue="BLOCKED")
}
)
})
public class XPoiDao extends PoiDao implements Serializable {
/**
*
*/
private static final long serialVersionUID = 2496267921294255723L;
// #Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
#Column(name="id")
private Integer id;
#Column(name="xPoiId")
private String xPoiId;
#Convert("xPoiStatusConverter")
#Column(name="status")
private XPoiStatusEnum status;
#Embedded
private ContactDao contact;
// #OneToMany(orphanRemoval=true, cascade=CascadeType.ALL, fetch=FetchType.LAZY)
// #JoinColumn(name="poiId",insertable=true,updatable=true)
// private List<ReservationDao> existingReservations;
#OneToMany(orphanRemoval=true, cascade=CascadeType.ALL, fetch=FetchType.LAZY)
#JoinColumn(name="parkingPoiId",insertable=true,updatable=true)
private List<OperatingHourDao> operatingHours;
...
}
You've got FetchType.LAZY in there. Do you get an empty list when you try to access it? Debuggers might not trigger the fetch requests.