Is there a way to select multiple columns in a subquery of hql?
I want to convert the following mysql query to hql
select u.name, sub.cnt from user u
inner join (select user_id, count(user_id) cnt from user_log group by user_id order by cnt desc limit 5) sub
on u.id = sub.user_id;
But in hql, I know that can use subquery only in where clause
I'm not aware of a pure Hibernate solution. I talk about that in my Blog post.
But there is a FluentJPA solution that you may consider:
FluentQuery query = FluentJPA.SQL((User u) -> {
UserIdCount sub = subQuery((UserLog log) -> {
int count = alias(COUNT(log.getUserId()), UserIdCount::getCount);
SELECT(log.getUserId(), count);
FROM(log);
ORDER(BY(count).DESC());
LIMIT(5);
});
SELECT(u.getName(), sub.getCount());
FROM(u).JOIN(sub).ON(u.getId() == sub.getUserId());
});
return query.createQuery(em, UserNameCount.class).getSingleResult();
which produces the following SQL:
SELECT t0.name, q0.count
FROM USER t0 INNER JOIN (SELECT t1.user_id, COUNT(t1.user_id) AS count
FROM USER_LOG t1
ORDER BY COUNT(t1.user_id) DESC
LIMIT 5 ) q0 ON (t0.id = q0.user_id)
Entities I used (declared with lombok):
#Entity
#Getter
#Table(name = "USER")
class User {
private Long id;
private String name;
}
#Entity
#Getter
#Table(name = "USER_LOG")
class UserLog {
private Long userId;
}
#Tuple
#Getter
class UserIdCount {
private Long userId;
private int count;
}
#Tuple
#Data
class UserNameCount {
private int count;
private String name;
}
Related
I am having trouble to converting the following postgresql query (with a join and a group by) to JPA criteria API for a Spring Boot, JPA, Hibernate application:
select u.id, u.full_name, count(*) project_applications_count from users u
join project_applications pa on pa.created_by = u.id
group by u.id, u.full_name
having count(*) >= 1 and count(*) <= 5
The tables look like this:
create table project_applications (
id serial primary key,
...
city_id integer not null references cities (id),
created_by integer not null references users (id)
);
create table users (
id serial primary key,
...
full_name varchar(100) not null
);
And the entities look like this:
#Entity
#Table(name = "project_applications")
public class ProjectApplication {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#ManyToOne
#JoinColumn(name = "created_by")
private User createdBy;
...
}
#Entity
#Table(name = "users")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Column(name = "full_name")
private String fullName;
...
}
I tried searching online for a solution but every exemple I found was using either a join or group by, but not both.
Using #akortex's idea with projections, I think something like this should work:
public class UserSummary {
private Long id;
private String fullName;
private Long count;
public UserSummary() {
}
public UserSummary(Long id, String fullName, Long count) {
this.id = id;
this.fullName = fullName;
this.count = count;
}
... (getters and setters)
}
public List<UserSummary> getSummaries(Integer minProjectAppsCount, Integer maxProjectAppsCount) {
CriteriaBuilder cb = _entityManager.getCriteriaBuilder();
CriteriaQuery<UserSummary> query = cb.createQuery(UserSummary.class);
Root<ProjectApplication> projectApp = query.from(ProjectApplication.class);
Join<ProjectApplication, User> userJoin = projectApp.join("createdBy", JoinType.INNER);
query.multiselect(userJoin.get("id"), userJoin.get("fullName"), cb.count(projectApp))
.groupBy(userJoin.get("id"), userJoin.get("fullName"));
List<Predicate> predicates = new ArrayList<>();
if (minProjectAppsCount != null ) {
Predicate p = cb.ge(cb.count(projectApp), minProjectAppsCount);
predicates.add(p);
}
if (maxProjectAppsCount != null ) {
Predicate p = cb.le(cb.count(projectApp), maxProjectAppsCount);
predicates.add(p);
}
query.having(predicates.toArray(new Predicate[0]));
return _entityManager.createQuery(query).getResultList();
}
You could potentially look into projections in order to achieve what you want.
For example consider the following projection and repository:
#Data
#AllArgsConstructor
public class ProjectApplicationSummary {
private Long id;
private String fullName;
private Long count;
}
And:
#Repository
public interface ProjectApplicationRepository extends JpaRepository<ProjectApplication, Long> {
#Query(
"""
SELECT new com.example.springdemo.entities.ProjectApplicationSummary(u.id, u.fullName, count(pa))
FROM User u, ProjectApplication pa
GROUP BY u.id, u.fullName
"""
)
List<ProjectApplicationSummary> getSummaries();
}
You will most likely need to tweak the query a bit (which revolves experimenting with JPQL) but other than that, the basic idea is there.
I'm not sure in my solution, but it should be similar. I took an idea from here. Maybe it helps you to resolve your problem.
public static Specification<User> getUsers() {
return Specification.where((root, query, criteriaBuilder) -> {
CriteriaQuery<User> criteriaQuery = criteriaBuilder.createQuery(User.class);
Subquery<Long> subQuery = criteriaQuery.subquery(Long.class);
Root<ProjectApplication> subRoot = subQuery.from(ProjectApplication.class);
subQuery
.select(criteriaBuilder.count(subRoot))
.where(criteriaBuilder.equal(root.get("id"), subRoot.get("createdBy").get("id")));
query
.multiselect(criteriaBuilder.construct(root.get("id"), root.get("fullName")))
.groupBy(root.get("id"), root.get("fullName"))
.having(criteriaBuilder.and(
criteriaBuilder.greaterThanOrEqualTo(subQuery.getSelection(), 1L),
criteriaBuilder.lessThanOrEqualTo(subQuery.getSelection(), 5L)));
return query.getRestriction();
});
}
I have two following entities:
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Entity
#Table(name = "affiliate_programs")
#SequenceGenerator(name = AbstractEntity.GENERATOR, sequenceName = "affiliate_programs_seq", allocationSize = 1)
public class AffiliateProgram extends AbstractAuditableDeletableEntity {
private static final int DESCRIPTION_LENGTH = 512;
#Column(nullable = false)
private String title;
#OneToMany(mappedBy = "affiliateProgram", fetch = FetchType.LAZY)
private Set<AffiliateProgramStatistics> statistics;
public enum SortType implements ISortType {
ID(QAffiliateProgram.affiliateProgram.id),
TITLE(QAffiliateProgram.affiliateProgram.title),
#Getter
private ComparableExpressionBase[] expressions;
SortType(final ComparableExpressionBase... expressions) {
this.expressions = expressions;
}
}
}
#Getter
#Setter
#NoArgsConstructor
#AllArgsConstructor
#Entity
#Table(name = "affiliate_programs_statistics")
#SequenceGenerator(name = AbstractEntity.GENERATOR, sequenceName = "affiliate_programs_statistics_seq", allocationSize = 1)
public class AffiliateProgramStatistics extends AbstractAuditableEntity {
#ManyToOne(fetch = FetchType.LAZY, optional = false, cascade = CascadeType.ALL)
private AffiliateProgram affiliateProgram;
#Enumerated(EnumType.STRING)
private EventType eventType;
private LocalDate date;
public enum EventType {
MERCHANTS,
PRIORITY_MERCHANTS,
COUPONS,
CLICKS
}
}
I am trying to fetch only the columns from AffiliateProgramStatistics that match the SQL between condition. My SQL query looks like this:
select *
from affiliate_programs ap
left join affiliate_programs_statistics aps on ap.id = aps.affiliate_program_id
where ap.deleted = false and aps.date between '2020-07-20' and '2020-08-20';
And the result of this query is exactly what I need - I get only columns that are NOT marked as deleted AND columns with date BETWEEN required dates.
I tried to write that query in QueryDSL and that's what I came up with:
#Repository
#RequiredArgsConstructor
public class AffiliateProgramsCustomRepositoryImpl implements AffiliateProgramsCustomRepository {
private final EntityManager entityManager;
#Override
public Page<AffiliateProgram> search(final AffiliateProgramSearchForm form) {
final QAffiliateProgram affiliateProgram = QAffiliateProgram.affiliateProgram;
final QAffiliateProgramStatistics affiliateProgramStatistics = QAffiliateProgramStatistics.affiliateProgramStatistics;
final JPAQuery<AffiliateProgram> query = new JPAQuery<AffiliateProgram>(entityManager)
.distinct()
.from(affiliateProgram)
.leftJoin(affiliateProgram.statistics, affiliateProgramStatistics)
.where(AffiliateProgramsRepositoryHelper.getPredicates(form))
.orderBy(AffiliateProgramsRepositoryHelper.getOrders(form.getSorting()))
.limit(form.getLimit())
.offset(form.getOffset());
return AffiliateProgramsRepositoryHelper.pageBy(query, form);
}
}
public class AffiliateProgramsRepositoryHelper extends RepositoryHelper {
public static Predicate[] getPredicates(final AffiliateProgramSearchForm form) {
final QAffiliateProgramStatistics affiliateProgramStatistics = QAffiliateProgramStatistics.affiliateProgramStatistics;
final List<Predicate> predicates = new ArrayList<>();
final String formattedQuery = form.getFormattedQuery();
if (!isNullOrEmpty(formattedQuery)) {
predicates.add(affiliateProgramStatistics.affiliateProgram.title.likeIgnoreCase(formattedQuery));
}
predicates.add(affiliateProgramStatistics.date.between(form.getFrom(), form.getTo()));
predicates.add(affiliateProgramStatistics.affiliateProgram.deleted.isFalse());
return predicates.toArray(new Predicate[0]);
}
}
But the result of this is not satisfying. If at least one of the columns in AffiliateProgramStatistics match the between() condition, it fetches every single column from the table that matches tje leftJoin() condition.
How can I fetch only the columns that I need?
P.S. Hibernate generates the following query:
Hibernate:
select distinct
affiliatep0_.id as id1_0_,
affiliatep0_.created_date_time as created_2_0_,
affiliatep0_.last_modified_date_time as last_mod3_0_,
affiliatep0_.deleted as deleted4_0_,
affiliatep0_.clicks_count as clicks_c5_0_,
affiliatep0_.coupons_count as coupons_6_0_,
affiliatep0_.description as descript7_0_,
affiliatep0_.merchants_count as merchant8_0_,
affiliatep0_.priority_merchants_count as priority9_0_,
affiliatep0_.priority_order as priorit10_0_,
affiliatep0_.title as title11_0_
from affiliate_programs affiliatep0_
inner join affiliate_programs_statistics statistics1_ on affiliatep0_.id=statistics1_.affiliate_program_id
cross join affiliate_programs affiliatep2_
where statistics1_.affiliate_program_id=affiliatep2_.id
and (statistics1_.date between ? and ?)
and affiliatep2_.deleted=?
order by affiliatep0_.title desc nulls last limit ?
which works perfectly and fetches only the data I need if i run it in console
JPA supports the ON clause in JPQL since 2.1, and QueryDSL is able to generate that ON clause in queries. Hibernate had a precedessor for the ON clause in the form of the now deprecated WITH clause. The ON clause can be used in more occasions.
Just use .on(Predicate) immediately after the join on which it should be applied:
final JPAQuery<AffiliateProgram> query = new JPAQuery<AffiliateProgram>(entityManager)
.distinct()
.from(affiliateProgram)
.leftJoin(affiliateProgram.statistics, affiliateProgramStatistics)
.on(AffiliateProgramsRepositoryHelper.getPredicates(form))
.orderBy(AffiliateProgramsRepositoryHelper.getOrders(form.getSorting()))
.limit(form.getLimit())
.offset(form.getOffset());
java.sql.SQLSyntaxErrorException: No such column: id
When table already contains the column id
I'm trying to have the following native SQL query that runs with expected results from within MariaDB SQL from a Repository class:
SELECT name
FROM table1 t1
WHERE t1.table2_id IN (
SELECT id
FROM table2 t2
WHERE t2.column1_number = 1 AND
t2.id IS NOT NULL
)
ORDER BY t1.name
The entity classes are as follows:
#Entity
#Table(name = "table1")
public class Table1 {
#Column(nullable = false)
private String name;
#Column(nullable = false)
private Integer number;
#ManyToOne
#JoinColumn(name = "table2_id")
private Table2 table2;
// Getters and Setters
}
#Entity
#Table(name="table2")
public class Table2 {
private Integer id;
private Integer column1_number;
#Override
public Integer getId() {
return id;
}
#Override
public void setId(Integer id) {
this.id = id;
}
// Getters and Setters
}
The Repository is:
#Repository
public interface Table1Repository extends JpaRepository<Table1, Integer> {
#Query(value = "SELECT name FROM table1 t1 WHERE t1.table2_id IN (SELECT id FROM table2 t2 WHERE t2.column1_number = ?1 AND t2.id IS NOT NULL) ORDER BY t1.name", nativeQuery = true)
List<Table1> findByNumberOrderByName(Integer number);
}
Any ideas as to why I am getting this error at run time? This error does not occur at compile time.
#Query(value = "SELECT name FROM table1 t1 WHERE t1.table2_id IN (SELECT id FROM table2 t2 WHERE t2.column1_number = ?1 AND t2.id IS NOT NULL) ORDER BY t1.name", nativeQuery = true)
List<Table1> findByNumberOrderByName(Integer number);
should have been List<String> and not List<Table1>
and so the solution was:
#Query(value = "SELECT name FROM table1 t1 WHERE t1.table2_id IN (SELECT id FROM table2 t2 WHERE t2.column1_number = ?1 AND t2.id IS NOT NULL) ORDER BY t1.name", nativeQuery = true)
List<String> findByNumberOrderByName(Integer number);
You are trying to search in table2 using id, but you didn't choose the correct mapping column from table1 which should be table2_id.id , so the query should be something like this
SELECT name FROM table1 t1 WHERE t1.table2_id.id IN (SELECT id FROM table2 t2 WHERE t2.column1_number = 1 AND t2.id IS NOT NULL) ORDER BY t1.name
Also note you're using native query, that means querying the db directly, so make sure you're using the same correct name in your database tables.
Try to add Id element to table1 and annotated both tables Id fields with #Id annotation like below.
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id")
private Long id;
Java, Spring Data JPA
I have 2 entities:
class Source {
Integer id;
String name;
}
class Item {
Integer id;
String name;
Integer sourceId;
}
I need statistic native query result like this:
select s.id source_id, s.name source_name, count(i.id) item_count
from source s
left join item i on s.id = i.source_id
group by s.id
And i want to have result in Java object MyResult:
class MyResult {
Source source;
Integer itemCount;
MyResult(Source source, Integer itemCount) {...}
}
The closest solution is using #SqlResultSetMapping like this:
#SqlResultSetMapping(
name = "MyResultMapping",
entities = {
#EntityResult(
entityClass = Source.class,
fields = {
#FieldResult(name = "id", column = "source_id"),
#FieldResult(name = "name", column = "source_name"),
}
),
...
???
}
)
OR
#SqlResultSetMapping(
name = "MyResultMapping",
classes = {
#ConstructorResult(
targetClass = MyResult.class,
columns = {
#ColumnResult(name = "???"),
???
}
)
}
)
With second variant i can use something like this:
MyResult(Integer sourceId, String sourceName, Integer itemsCount) {
this.source = new Source(sourceId, sourceName);
this.itemsCount = itemsCount;
}
but i want it to automate with #SqlResultSetMapping... (because my real objects more complex)
With Spring Data JPA it's better to use projections to achieve you need, for example:
public interface SourceWithItemCount {
Source getSource();
Integer getItemCount();
}
Then in your Source repository create HQL query method, like this:
public interface SourceRepo extends JpaRepository<Source, Integer> {
#Query("select s as source, count(i) like itemCount from Source s left join Item i on i.sourceId = s.id group by s"
List<SourceWithItemCount> getSourcesWithItemCount();
}
Important note is to use aliases for returned values (s as source etc.) it's allows Spring Data JPA to map them to projections properties.
Join on <condition> works from Hibernate version 5.1+ (if I'm not mistaken) so I recommend you to create classic one-to-many relation between your objects, like this, for example:
#Entity
class Source {
#Id private Integer id;
private String name;
#OneToMany #JoinColumn(name = "source_id") private List<Item> items;
}
#Entity
class Item {
#Id private Integer id;
private String name;
}
Then create JPQL query method supported by all versions of Hibernate (and other ORM providers):
#Query("select s as source, count(i) like itemCount from Source s left join s.items i group by s"
List<SourceWithItemCount> getSourcesWithItemCount();
I have classes A, B
class A{
#Embedded
private B objB;
}
#Embeddable
class B{
Integer x;
Integer y;
float z;
}
Now I have a bunch of class A objs Set, I want to query the database, so that rows contain same x and y in Class B (z is not important in comparison in this case) should be selected, how do I achieve that?
It's like "In" in SQL, but since I am comparing embedded objects, how should I do with it ? Many thanks!!
Given the classes:
public class RandomEntity {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
#Embedded
private EmbeddableEntity embedded;
}
and
#Embeddable
public class EmbeddableEntity {
private Long valueA;
private Long valueB;
}
You can query it like:
session.createQuery( "select a from RandomEntity a where a.embedded.valueA=:value" ).setParameter( "value", 1L ).list();
Hibernate: select randomenti0_.id as id1_2_, randomenti0_.valueA as valueA2_2_, randomenti0_.valueB as valueB3_2_ from RandomEntity randomenti0_ where randomenti0_.valueA=?
or:
session.createQuery( "select a from RandomEntity a where a.embedded.valueA in (:value)" ).setParameterList( "value", Arrays.asList( 1L, 2L ) ).list();
Hibernate: select randomenti0_.id as id1_2_, randomenti0_.valueA as valueA2_2_, randomenti0_.valueB as valueB3_2_ from RandomEntity randomenti0_ where randomenti0_.valueA in (?)