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Map Query result to dto

I have these 3 independent table i.e Student, Teacher and Subject. Independent here refers that there is no relation in these tables.
I want the count of all these tables . SQL query looks like -
SELECT
(SELECT COUNT(*) FROM Student as ST,
(SELECT COUNT(*) FROM Teacher as TE,
(SELECT COUNT(*) FROM Subject as SU
Now I want to map this result into dto .
The DTO looks like
public class CountDto{
Integer student;
Integer teacher;
Integer subject;
}
The repository call looks like -
#Query(value = "SELECT\r\n"
+ " (SELECT COUNT(*) FROM Student) as ST, \r\n"
+ " (SELECT COUNT(*) FROM Teacher) as TE,\r\n"
+ " (SELECT COUNT(*) FROM Subject) as SU", nativeQuery = true)
public CountDto getCount();
While calling this function I get following error stating
"message": "Failed to convert from type [java.lang.Object[]] to type [com.rbl.mdm.dto.CountDto ] for value '{16, 16 , 34}'; nested exception is org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.Integer] to type [com.rbl.mdm.dto.CountDto]"
How should I convert my response to desired DTO ?

You can declare CountDto as a public interface and it should work. It's called a Projection in terms of Spring. Or you can use SqlResultSetMapping or ConstructorResult along with your class.
you don't have to implement it by any entity class, just create it like an independent interface even within the repository file:
public interface StudentRepository extends CrudRepository<Student, Long> {
#Query(value = "SELECT\r\n"
+ " (SELECT COUNT(*) FROM Student) as ST, \r\n"
+ " (SELECT COUNT(*) FROM Teacher) as TE,\r\n"
+ " (SELECT COUNT(*) FROM Subject) as SU", nativeQuery = true)
Counts getCount();
public static interface Counts {
Integer getST();
Integer getTE();
Integer getSU();
}
}

So here is the answer to do -
The DTO will look like
public CountDto{
private Integer studentTotal;
private Integer teacherTota;
private Integer subjectTotal;
}
The repository call -
#Query(value = "SELECT\r\n"
+ " (SELECT COUNT(*) FROM Student) as ST, \r\n"
+ " (SELECT COUNT(*) FROM Teacher) as TE,\r\n"
+ " (SELECT COUNT(*) FROM Subject) as SU", nativeQuery = true)
public Map<String,Integer> getCount();
Finally the serviceImpl--
public CountDto getCount{
CountDto CountValue = new CountDto();
Map<String,Integer> map = repository.getCount();
for (Map.Entry<String,Integer> entry : map.entrySet()) {
if(entry.getKey().equals("ST"))
CountValue.setStudentTotal( entry.getValue());
if(entry.getKey().equals("TE"))
CountValue.setTeacherTotal( entry.getValue());
if(entry.getKey().equals("SU"))
CountValue.setSubjectTotal( entry.getValue());
}
return CountValue ;
}
But the solution seems quite complex to me. Any simpler approach required.

In pure Hibernate/JPA usage this is a simple dynamic-instantiation query (what JPA calls a "constructor result"):
select new CountDTO(
(SELECT COUNT(*) FROM Student) as ST,
...
)
No idea here about Spring, though a word of warning.. in trying to be useful, it often "gets in the way". Not sure that is the case here... Have you tried straight Hibernate/JPA?

Named param not being detected

I have a simple query as follows. I get the expected result if I hard code the id value as follows. But it throws IllegalArgumentException exception if I try to get the value from the Param instead. Note that I have tried to use the Param as both long and String and still the same results. Please advise what I am doing wrong. Thanks.
My Query
public interface FeedDetailRepository extends JpaRepository<FeedDetail, Long> {
#Query("select fd.message from FeedDetail as fd where fd.feedId =: id")
String custom(#Param("id") long id);
}
At Controller, if I run the following, I get an exception.
#GetMapping("/something/{id}")
public String getDetail(#PathVariable long id){
return feedDetailRepository.custom(id);
}
But if I hard code the id value as follows, I get the wanted result.
public interface FeedDetailRepository extends JpaRepository<FeedDetail, Long> {
#Query("select fd.message from FeedDetail as fd where fd.feedId = 4")
String getDetailBasedOnFeedId(#Param("id") long id);
}
The exception
nested exception is java.lang.IllegalArgumentException:
org.hibernate.QueryException: Named parameter not bound : id

I would change
#Query("select fd.message from FeedDetail as fd where fd.feedId =: id")
To (difference lies in space)
#Query("select fd.message from FeedDetail as fd where fd.feedId = :id")
This is a small difference for you but big for Spring. He recognizes a parameter by attaching name to colon like that
:id
For more details refer to the official Spring Data JPA Reference.

I had the same issue:
Wrong query:
SELECT * FROM `cars` as c where c.driver_one = :id OR c.driver_two = **:id;**
Correct query:
SELECT * FROM `cars` as c where c.driver_one = :id OR c.driver_two = **:id**

This is likely because of the way you have provided space with in the query.
My suggestion would be to format the code and in the string quotes use something similar
SELECT fd.message from FeedDetail AS fd where fd.feedId = :id

query all row in table that is link from another table using query builder

I have a table that have few rows of variable. One of this row link to another table that have more rows.
To put it clear, 1 table is called Connection. The variable is:
name, groupname, etc.
The groupname should link to a second table called ConnectionGroup. The variable is:
name, id.
My idea is to query to the ConnectionGroup table by name. The abstract class for Connection and ConnectionGroup is like this:
public abstract class Connection_ {
public static volatile SingularAttribute<Connection, String>name;
public static volatile SingularAttribute<Connection, String>host;
public static volatile SetAttribute<Connection, ConnectionGroup>connectionGroups;
}
public abstract class ConnectionGroup_ {
public static volatile SingularAttribute<ConnectionGroup, String> name;
public static volatile SingularAttribute<ConnectionGroup, Long> id;
}
To query this, I assume I have to join these 2 table and then only query them. This is the code that I have tried:
#PersistenceContext
private EntityManager em;
public List<Connection> retrieveAll( String groupFilter, int start, int length) {
ServiceUtil.requireAdmin();
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Connection> q = cb.createQuery(Connection.class);
Root<Connection> c = q.from(Connection.class);
Join<Connection, ConnectionGroup> join = c.join(Connection_.connectionGroups);
q.select(c);
c.fetch(Connection_.connectionGroups).fetch(ConnectionGroup_.id);
Predicate groupPredicate = cb.equal(
c.get(Connection_.connectionGroups), "%" + groupFilter + "%");
q.where(groupPredicate);
List<Connection> results = em.createQuery(q).setFirstResult(start)
.setMaxResults(length).getResultList();
for (Connection conn : results) {
logger.info( "getconnectionGroups =["+ conn.getConnectionGroups() + "]");
for (ConnectionGroup conngroup : conn.getConnectionGroups()) {
logger.info("connectiongroups = [" + conngroup.getName() + "]");
}
}
}
Things that I have tried, changing this:
Predicate groupPredicate = cb.equal(
c.get(Connection_.connectionGroups), "%" + groupFilter + "%");
to this:
Predicate groupPredicate = cb.equal(join.get(ConnectionGroup_.name),
"%" + groupFilter + "%");
Changing this:
Join<Connection, ConnectionGroup> join = c
.join(Connection_.connectionGroups);
To this:
Join<Connection, ConnectionGroup> join = c.join("connectionGroups");
When I tried these method, I keep getting an exception Cannot join to attribute of basic type
I also tried changing the code into this:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Connection> q = cb.createQuery(Connection.class);
Root<Connection> c = q.from(Connection.class);
Join<Connection, ConnectionGroup> join = (Join<Connection, ConnectionGroup>) c.fetch(Connection_.connectionGroups);
q.select(c);
Predicate groupPredicate = cb.equal(join.get(ConnectionGroup_.name), "%" + groupFilter + "%");
q.where(groupPredicate);
List<Connection> results = em.createQuery(q).setFirstResult(start)
.setMaxResults(length).getResultList();
Which return an exception:
query specified join fetching, but the owner of the fetched association was not present in the select list
I'm using these site as reference to write the code:
JPA CriteriaBuilder using fetch joins and result objects
JPA 2 Criteria Fetch Path Navigation
wiki.eclipse.org
developer.com
How can I query the name from ConnectionGroup table? Is my approach wrong?

If you're trying to use filtering by name through string matching, CriteriaBuilder.like() is more appropriate to use than CriteriaBuilder.equal().
To achieve what you're trying to query, you can use the ff. JP QL query:
SELECT DISTINCT conn FROM Connection conn JOIN conn.connectionGroups connGrp
WHERE connGrp.name LIKE :groupFilter
Translating JP QL to CriteriaQuery, you'll have:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Connection> q = cb.createQuery(Connection.class);
Root<Connection> conn = q.from(Connection.class);
Join<Connection, ConnectionGroup> connGrp = conn.join(Connection_.connectionGroups);
q.select(conn).distinct(true);
ParameterExpression<String> param = cb.parameter(String.class, "%"+ groupFilter + "%");
q.where(cb.like(connGrp.get(ConnectionGroup_name), param));

spring data jpa #query and pageable

I'm using Spring Data JPA, and when I use #Query to to define a query WITHOUT Pageable, it works:
public interface UrnMappingRepository extends JpaRepository<UrnMapping, Long> {
#Query(value = "select * from internal_uddi where urn like %?1% or contact like %?1%",
nativeQuery = true)
List<UrnMapping> fullTextSearch(String text);
}
But if I add the second param Pageable, the #Query will NOT work, and Spring will parse the method's name, then throw the exception No property full found. Is this a bug?
public interface UrnMappingRepository extends JpaRepository<UrnMapping, Long> {
#Query(value = "select * from internal_uddi where urn like %?1% or contact like %?1%",
nativeQuery = true)
Page<UrnMapping> fullTextSearch(String text, Pageable pageable);
}

You can use pagination with a native query. It is documented here: Spring Data JPA - Reference Documentation
"You can however use native queries for pagination by specifying the count query yourself:
Example 59. Declare native count queries for pagination at the query method using #Query"
public interface UserRepository extends JpaRepository<User, Long> {
#Query(value = "SELECT * FROM USERS WHERE LASTNAME = ?1",
countQuery = "SELECT count(*) FROM USERS WHERE LASTNAME = ?1",
nativeQuery = true)
Page<User> findByLastname(String lastname, Pageable pageable);
}

A similar question was asked on the Spring forums, where it was pointed out that to apply pagination, a second subquery must be derived. Because the subquery is referring to the same fields, you need to ensure that your query uses aliases for the entities/tables it refers to. This means that where you wrote:
select * from internal_uddi where urn like
You should instead have:
select * from internal_uddi iu where iu.urn like ...

Considering that the UrnMapping class is mapped to the internal_uddi table, I would suggest this:
#Repository
public interface UrnMappingRepository extends JpaRepository<UrnMapping, Long> {
#Query(value = "select iu from UrnMapping iu where iu.urn like %:text% or iu.contact like %:text%")
Page<UrnMapping> fullTextSearch(#Param("text") String text, Pageable pageable);
}
Please note that you might have to turn off native queries with dynamic requests.

With #Query , we can use pagination as well where you need to pass object of Pageable class at end of JPA method
For example:
Pageable pageableRequest = new PageRequest(page, size, Sort.Direction.DESC, rollNo);
Where,
page = index of page (index start from zero)
size = No. of records
Sort.Direction = Sorting as per rollNo
rollNo = Field in User class
UserRepository repo
repo.findByFirstname("John", pageableRequest);
public interface UserRepository extends JpaRepository<User, Long> {
#Query(value = "SELECT * FROM USER WHERE FIRSTNAME = :firstname)
Page<User> findByLastname(#Param("firstname") String firstname, Pageable pageable);
}

Please reference :Spring Data JPA #Query, if you are using Spring Data JPA version 2.0.4 and later. Sample like below:
#Query(value = "SELECT u FROM User u ORDER BY id")
Page<User> findAllUsersWithPagination(Pageable pageable);

Declare native count queries for pagination at the query method by using #Query
public interface UserRepository extends JpaRepository<User, Long> {
#Query(value = "SELECT * FROM USERS WHERE LASTNAME = ?1",
countQuery = "SELECT count(*) FROM USERS WHERE LASTNAME = ?1",
nativeQuery = true)
Page<User> findByLastname(String lastname, Pageable pageable);
}
Hope this helps
https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#jpa.query-methods

Rewrite your query to:
select iu from internal_uddi iu where iu.urn....
description: http://forum.spring.io/forum/spring-projects/data/126415-is-it-possible-to-use-query-and-pageable?p=611398#post611398

I found it works different among different jpa versions, for debug, you'd better add this configurations to show generated sql, it will save your time a lot !
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
for spring boot 2.1.6.RELEASE, it works good!
Sort sort = new Sort(Sort.Direction.DESC, "column_name");
int pageNumber = 3, pageSize = 5;
Pageable pageable = PageRequest.of(pageNumber - 1, pageSize, sort);
#Query(value = "select * from integrity_score_view " +
"where (?1 is null or data_hour >= ?1 ) " +
"and (?2 is null or data_hour <= ?2 ) " +
"and (?3 is null or ?3 = '' or park_no = ?3 ) " +
"group by park_name, data_hour ",
countQuery = "select count(*) from integrity_score_view " +
"where (?1 is null or data_hour >= ?1 ) " +
"and (?2 is null or data_hour <= ?2 ) " +
"and (?3 is null or ?3 = '' or park_no = ?3 ) " +
"group by park_name, data_hour",
nativeQuery = true
)
Page<IntegrityScoreView> queryParkView(Date from, Date to, String parkNo, Pageable pageable);
you DO NOT write order by and limit, it generates the right sql

I had the same issue - without Pageable method works fine.
When added as method parameter - doesn't work.
After playing with DB console and native query support came up to decision that method works like it should. However, only for upper case letters.
Logic of my application was that all names of entity starts from upper case letters.
Playing a little bit with it. And discover that IgnoreCase at method name do the "magic" and here is working solution:
public interface EmployeeRepository
extends PagingAndSortingRepository<Employee, Integer> {
Page<Employee> findAllByNameIgnoreCaseStartsWith(String name, Pageable pageable);
}
Where entity looks like:
#Data
#Entity
#Table(name = "tblEmployees")
public class Employee {
#Id
#Column(name = "empID")
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
#NotEmpty
#Size(min = 2, max = 20)
#Column(name = "empName", length = 25)
private String name;
#Column(name = "empActive")
private Boolean active;
#ManyToOne
#JoinColumn(name = "emp_dpID")
private Department department;
}

When using nativeQuery that is having (nativeQuery = true), you may do the pagination yourself in the query by adding (LIMIT :sizeValue OFFSET :page)
Note:
Your page value passed to this method should be offset * size
Example
#Query(value = "SELECT * FROM person " +
"LIMIT ?1 OFFSET ?2", nativeQuery = true)
Optional<List<TDriverJob>> findPersons(int size, int page);

I tried all above solution and non worked , finally I removed the Sorting from Pagination and it worked

the following tutorial helped me
-> https://www.baeldung.com/spring-data-jpa-query
At this point 4.3. Spring Data JPA Versions Prior to 2.0.4
VERY IMPORTANT to add \ n-- #pageable \ n
Without this I was wrong
Also the pagination setting must be without ordering
PageRequest paginaConf = new PageRequest ((param1 - 1)
, param2);
Finally to convert the Page <Object []>
Page <Object []> list = myQueryofRepo ();
List <XXXModel> lstReturn = myConversor (list.getContent ());
Page <XXXModel> ret = new PageImpl <XXXModel> (lstReturn, pageConf, param2);

This bugged me for a while but I managed with a very smooth solution.
The challenge is JPA did not automatically detect the count query so I resolved to use the countName which according JPA docs Returns the name of the javax.persistence.NamedQuery to be used to execute count queries when pagination is used. Will default to the named query name configured suffixed by .count.
So I created a named query
#NamedNativeQuery(
name = "[queryName].count",
query = [your count query],
resultSetMapping = "[query resultSetMapping name]"
)
}
As indicated, the count query should be suffixed with .count
Count query returns Long so add the resultSetMapping as
#SqlResultSetMapping(
name="[query resultSetMapping name]",
columns={#ColumnResult(name="count", type = Long.class)})
Then in your repository, use the count query as indicated below
#Query(countName ="[queryName].count" , nativeQuery = true)
Page<Object> [mainQuery](...params)
Hope this helps!

IN-clause in HQL or Java Persistence Query Language

I have the following parametrised JPA, or Hibernate, query:
SELECT entity FROM Entity entity WHERE name IN (?)
I want to pass the parameter as an ArrayList<String>, is this possible? Hibernate current tells me, that
java.lang.ClassCastException: java.util.ArrayList cannot be cast to java.lang.String
Is this possible at all?
ANSWER: Collections as parameters only work with named parameters like ":name", not with JDBC style parameters like "?".

Are you using Hibernate's Query object, or JPA? For JPA, it should work fine:
String jpql = "from A where name in (:names)";
Query q = em.createQuery(jpql);
q.setParameter("names", l);
For Hibernate's, you'll need to use the setParameterList:
String hql = "from A where name in (:names)";
Query q = s.createQuery(hql);
q.setParameterList("names", l);

in HQL you can use query parameter and set Collection with setParameterList method.
Query q = session.createQuery("SELECT entity FROM Entity entity WHERE name IN (:names)");
q.setParameterList("names", names);

Leaving out the parenthesis and simply calling 'setParameter' now works with at least Hibernate.
String jpql = "from A where name in :names";
Query q = em.createQuery(jpql);
q.setParameter("names", l);

Using pure JPA with Hibernate 5.0.2.Final as the actual provider the following seems to work with positional parameters as well:
Entity.java:
#Entity
#NamedQueries({
#NamedQuery(name = "byAttributes", query = "select e from Entity e where e.attribute in (?1)") })
public class Entity {
#Column(name = "attribute")
private String attribute;
}
Dao.java:
public class Dao {
public List<Entity> findByAttributes(Set<String> attributes) {
Query query = em.createNamedQuery("byAttributes");
query.setParameter(1, attributes);
List<Entity> entities = query.getResultList();
return entities;
}
}

query.setParameterList("name", new String[] { "Ron", "Som", "Roxi"}); fixed my issue