Spring DATA JPA question... I am trying to write a query to access the data in my sql join table.
I have my join table set up as follows:
#Entity
#Table(name="WritingCompany")
public class WritingCompany {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "companyId")
private Long id;
// private String companyName;
#ManyToMany
#JoinTable(name = "Join-WritingCo-Carrier",
joinColumns = #JoinColumn(name="writingCo"),
inverseJoinColumns = #JoinColumn(name="carrier")
)
private Set<CarrierAppointment> carriers;
//...getters and setters
}
public class CarrierAppointment {
// ...
#ManyToMany(
cascade=CascadeType.ALL,
mappedBy = "companyName"
)
private Set<WritingCompany> companies;
public Set<WritingCompany> getCompanies() {
return companies;
}
public void setCompanies(Set<WritingCompany> companies) {
this.companies = companies;
}
//...
}
I am unsure which class repository I need to write the query for... I am trying to find all the writingCo names from the join table that all have the same carrier id that matches one specific carrier.
The Join Table is set up through writing company but I feel like it should be accessed through CarrierAppointment Repository since I am matching carrier Id's.
This is what I've tried in the CarrierAppointmentrepository and it throws this error (unexpected token: Join near line 1, column 94):
#Query("Select companyName FROM WritingCompany INNER JOIN CarrierAppointment ON Join-WritingCo-Carrier.carrier= CarrierAppointment.CarrierAppointmentId")
List<CarrierAppointment> findCarrierAppoinmentFromJoin(CarrierAppointment carrier);
I've also tried:
#Query("SELECT writingCo FROM Join-WritingCo-Carrier WHERE carrier= CarrierAppointment.CarrierAppointmentId")
List<CarrierAppointment> findCarrierAppoinmentFromJoin(CarrierAppointment carrier);
Then I tried this in the writingCompanyRepository which also throws a similar error:
#Query("Select companyName FROM WritingCompany INNER JOIN CarrierAppointment ON Join-WritingCo-Carrier.carrier= CarrierAppointment.CarrierAppointmentId")
List<WritingCompany> findAllWithDescriptionQuery(CarrierAppointment carrier);
I am having a hard time understanding what this query is saying. Do I ever need to access the columns from the sql join table, or am I just querying around the join table by asking for each class that is making up the join columns in the join table? What is the right part of the statement, after INNER JOIN stating ? Could someone please provide a deeper explanation of why the query is written so I can figure out why it's not working? I've been reading a lot of inner join examples and just can't seem to figure it out.
Related
I have an issue to add the result of a subquery as part of the selection.
This is how my data model looks like:
#Entity
#Table(name = "flow")
public class Flow {
#Id
Long id;
#OneToMany(mappedBy="flow", fetch = FetchType.LAZY)
Set<Subscription> subscribers;
... other internal fields
//extra fields that come from other tables
#Transient //as it is not part of the model sometimes must be null
Long numberOfActiveSubscribers;
}
#Entity
#Table(name = "subscriptions")
public class Subscription {
#Id
Long id;
#ManyToOne
#JoinColumn(name = "idflow")
Flow flow;
#OneToMany(name = "user")
User user;
#Column(name = "active")
boolean active;
}
I need to implement a query using jpa specifications that will include in its definition the number of user that have active subscriptions to the flow. So that I will be able to use pagination over that, including sort by this field that is not part of the original flow table. The SQL query I came out with look like this:
SELECT f.*,
(SELECT count(sf.id)
FROM subscription sf
WHERE sf.active = true
AND sf.idf = f.id) as numberofactivesubscribers,
FROM flow f;
I would like to us it in a findAll method like so:
this.repository.findAll(new Specification<Flow>() {
#Override
public Predicate toPredicate(Root<Flow> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
Subquery<Long> sq = query.subquery(Long.class);
Root<Subscription> subsRoot = sq.from(Subscription.class);
sq.select(cb.count(subsRoot.get("id")))
.where(cb.equal(subsRoot.get("flow"), flowRoot),
cb.equal(subsRoot.get("active"), true));
//I DONT KNOW HOW TO INCLUDE THIS AS A PART OF THE MAIN SELECT OF THIS QUERY
}
}, pagination);
But as you can see I don't know how to include the subquery as part of the select method as I did in my SQL query.
I have Pojo mapped with JPA annotations like this
#Entity
#Table(name = "record")
public class SearchRecord {
#Id
#GeneratedValue(strategy = GenerationType.SEQUENCE)
private int id;
private String vidName;
#ElementCollection
private List<String> videoLabels = new ArrayList<String>();
and would like to run a Hibernate query that filters out all SearchRecords that match/contain 1..n videoLabels. (only objects that match all of the videoLabels)
I was able to search for SearchRecords that match a single label by running the following query:
String labelCar = "Car";
String labelPerson = "Person";
TypedQuery<SearchRecord> query = em.createQuery("SELECT b FROM SearchRecord b JOIN b.videoLabels l WHERE l = :param1",SearchRecord.class);
query.setParameter("param1", labelCar);
List<SearchRecord> results = query.getResultList();
But how can I execute a query filtering out all SearchResults matching Car and Person?
Thanks for your support
I was able to solve the problem with the following query
SELECT DISTINCT a FROM SearchRecord a JOIN a.labels b JOIN a.labels c WHERE b.name = 'Car' and c.name = 'Person'
I have 2 tables:
course: id, name
student: id, course_id, age
Tables are tied with oneToMany annotation
I am trying to write a hibernate query against course that will return courses and students that are x years 0ld. That's my attempt:
SELECT c from Course c RIGHT JOIN c.student p ON p.age = 20
It returns a course that has at least one student that is 20. when there are more students that are not 20, they are included in the result set as well. Is there a way to restrict the joined table values?
Edit:
These are my entities:
public class Course implements Serializable {
private static final long serialVersionUID = 646349111982187812L;
#Id
#Column(name = "id", unique=true, nullable=false)
private String id;
#Column(name = "name", unique=false, nullable=false)
private String name;
#OneToMany(cascade={CascadeType.ALL, CascadeType.REMOVE},
fetch=FetchType.LAZY, mappedBy = "Course")
#OrderBy("age")
#JsonManagedReference
private Set<Student> students;
getters and setters ...
}
public class Student implements Serializable {
private static final long serialVersionUID = 646349221337813L;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
#Column(name = "age", unique=false, nullable=true)
private String age;
#ManyToOne()
#JsonBackReference
private Course course;
}
I am trying to use this method from my crudrepository to get the expected result:
#Query(?????)
public List<Course> findCoursesWithAdults(#Param("age")int age)
it sounds like you want an inner join instead of a right join
SQL
SELECT distinct c.* from Course c inner join Student p on (c.id=p.course_id and p.age=20)
or with hql
select distinct c from Course c inner join c.student p with p.age=20
in order to get the information you are requesting, you will either have to limit the Set in Course using #Where ("age = 20" ) or simply deal with a list of students instead of courses.
select p from Course c inner join c.student p with p.age=20
you can reference the attached course object through any one of the getCourse methods on the student objects. You could also use "group by" here to help you order things.
or you can use a filter within the hibernate Entity...
#Transient
public List<Students> getStudents(Integer age){
List<Students> tmp = new ArrayList<>();
for(Student s: getStudents())
if(s.getAge().equals(age))tmp.add(s);
return tmp;
}
one more edit and im done... there is another way to do this that i didnt mention..
a select wrapper query.
create a wrapper object for your course and student
public class CourseWrapper(){
private Course c;
private List<Students> p = new ArrayList<>();
....constructor ... getters ...setters
}
select new CourseWrapper(c, students)
from Course c
left outer join c.students p with p.age=20'
more info here
SELECT c.name, s.id
FROM course c
INNER JOIN student s ON c.id = s.course_id
WHERE s.age = 20
I can't find this anywhere, but it seems pretty trivial. So, please excuse if this is a duplicate.
I have something like:
public class Doctor : Entity
{
...some other properties here...
public virtual string Email { get; set; }
}
public class Lawyer : Entity
{
...some other properties here...
public virtual string Email { get; set; }
}
I want to return all doctors where there is no email match in the Lawyers table like:
select * from Doctors d
where d.Email not in
(select l.Email from Lawyers l where l.Email is not null)
or using a join:
select d.* from Doctors d
left join Lawyers l on l.Email = d.Email
where l.Email is null
The problem is that the Email is of course not set up as a foreign key. I have no mapped property on the Doctor entity that maps to Lawyer.
What I've tried so far:
ICriteria criteria = Session.CreateCriteria(typeof(Doctor))
.CreateAlias("Lawyers.Email", "LawyerEmail", JoinType.LeftOuterJoin)
.Add(Restrictions.IsNull("LawyerEmail"));
return criteria.List<Doctor>();
But, I get a "cannot resolve property Lawyer of MyPlatform.MyNamespace.Doctor" error. Any ideas how to set up my DoctorMap and adjust the criteria tomfoolery to achieve this?
NHibernate for the loss........Entity Framework for the win....
We can achieve that with a feature called subquery:
// a inner SELECT to return all EMAILs from Lawyer table
var subQuery = DetachedCriteria.For<Lawyer>()
.SetProjection(Projections.Property("Email"));
// the root SELECT to get only these Doctors
var criteria = session.CreateCriteria<Doctor>();
// whos email is not in the sub SELECT
criteria.Add(Subqueries.PropertyNotIn("Email", subQuery));
// get first 10
var result = criteria
.SetMaxResults(10)
.SetFirstResult(0) // paging
.List<Doctor>();
I just wrote an sql query :
DELETE FROM basisgegevens.gm_persoonburgstaat pbs
WHERE (pbs.ingangsdatum, pbs.id_persoon) in (
SELECT pbs2.ingangsdatum, pbs2.id_persoon
FROM basisgegevens.gm_persoonburgstaat pbs2
WHERE pbs2.ingangsdatum = pbs.ingangsdatum
AND pbs2.id_persoon = :persoonID
AND pbs2.id_persoonburgerlijkestaat > pbs.id_persoonburgerlijkestaat);
I need to rewrite it to JPQL, but am getting stuck with the subquery refrencing the outer query.
public class PersoonBurgerlijkeStaatEntity {
#Column(name = "id_persoonburgerlijkestaat"
private Long identifier;
private Date ingangsdatum;
#ManyToOne
#JoinColumn(name = "id_persoon", referencedColumnName = "id_persoon", nullable = false)
private PersoonEntity persoon;
}
The persoon entity has an identifier
Can someone help me rewrite this?
Thanks
Not sure about this but give a try.
DELETE FROM persoonburgstaat person where (person.ingangsdatum, person identifier) in
(select p.ingangsdatum, p.identifier from persoonburgstaat p
left join p.persoon per where per.id_persoon = :persoonID
AND per.id_persoonburgerlijkestaa > p.identifier)
the left join will make the outer query
But to be more sure post PersoonEntity entity as I think " id_persoonburgerlijkestaa " is the name of the column not the property and query will fail based on that.