I have a case statement in my Native query where I am attempting to override a field in my entity.
SELECT i.id, i.ONE_TO_ONE_ID, i.ANOTHER, CASE(WHEN condition THEN 'YES' WHEN another_condition THEN 'NO' ELSE 'MAYBE' END) as word ....
I am using this with JpaRepository as a native query, with pagination.
When I run the native query against my db directly, the result set looks as though I expect.
| id_value | MAPPED_ENTITY_ID_value | another value | word_value (YES) |
When I run the native query from my JpaRepository, everything works there, except word is always null. I cant' seem to figure out how to map the additional String word result to a field in my Entity.
Is there a way to get this to map? Or will I have to create an entire #SqlResultSetMapping() for all of my fields coupled with a native query? (hoping not)
UPDATE: 1
I was generalizing above. Here is my Query.
#Query(
name = "listPagedMapping",
value = "SELECT DISTINCT i.ID, i.INSTANCE_ID, i.REGION, i.CNAME_STACK_ID, i.INSTANCE_STATE, i.IP_ADDRESS, i.EC2_ROLE_NAME, i.INSTANCE_OWNER, i.IS_MASTER, i.EC2_MASTER_ID, i.CNAME, i.EC2_START_TIMESTAMP, i.PRIVATE_DNS, i.INSTANCE_NAME, i.AUTO_TERMINATE, i.AUTO_TERMINATE_DATE, i.TERMINATION_ZONE, i.ADMIN_GROUP_AD_LDAP_ID, i.USER_GROUP_AD_LDAP_ID, (CASE WHEN i.INSTANCE_OWNER=:username THEN 'OWNER' WHEN i.ADMIN_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID) THEN 'ADMIN' WHEN i.USER_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID) THEN 'USER' END) as PERMISSION FROM USER u, USER_ACCESS_GROUPS g, EC2_PROVISIONING i WHERE i.INSTANCE_OWNER=:username and i.INSTANCE_STATE in (:instanceStates) or u.username=:username and i.INSTANCE_STATE in (:instanceStates) and g.USER_ID=u.USER_ID and (i.ADMIN_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID) or i.USER_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID))",
countQuery = "SELECT count(*) FROM (SELECT DISTINCT i.* FROM USER u, USER_ACCESS_GROUPS g, EC2_PROVISIONING i WHERE i.INSTANCE_OWNER=:username and i.INSTANCE_STATE in (:instanceStates) or u.username=:username and i.INSTANCE_STATE in (:instanceStates) and g.USER_ID=u.USER_ID and (i.ADMIN_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID) or i.USER_GROUP_AD_LDAP_ID IN (g.AD_LDAP_ID))) as ug",
nativeQuery = true)
Page<Ec2Instance> findAllByPermissionUserAdminOrOwnerAndInstanceStateIn(
#Param("username")final String username,
#Param("instanceStates") final Set<String> instanceStates,
final Pageable pageable);
}
Obviously a bit more complex.
I can get it to map to the entity field with using a named query, but then I loose all the default mappings:
#JsonInclude(JsonInclude.Include.NON_NULL)
#SuppressWarnings("unused")
#Data
#AllArgsConstructor
#NoArgsConstructor
#EqualsAndHashCode(exclude={"masterNode", "workers", "associatedBuckets"})
#Entity
#Table(name = "EC2_PROVISIONING")
#SqlResultSetMapping(
name="listPagedMapping",
columns = {
#ColumnResult(name = "permission", type = String.class)
}
)
#NamedNativeQuery(
name = "listAccessibleInstances",
query = ACCESSIBLE_QUERY,
resultSetMapping = "listPagedMapping"
)
public class Ec2Instance {
....
private String permission;
#column(name = "INSTANCE_ID")
private String instanceId;
#ManyToOne
#JoinColumn(name = "EC2_MASTER_ID")
private Ec2Instance masterNode;
#Setter(AccessLevel.NONE)
#ManyToMany(fetch = FetchType.EAGER)
#JoinTable(name = "WORKER_EC2_NODES", joinColumns = { #JoinColumn(name = "EC2_MASTER_ID") }, inverseJoinColumns = {
#JoinColumn(name = "ID") })
private Set<Ec2Instance> workers = new HashSet<>();
... More fields ..
}
I guess, I am hoping there is a way to provide a single mapping on-top of the default mapping that is done by ORM. The above code results in only a pageable of Content PERMISSION, rather than the whole entity + permission.
UPDATE: 2
Ok, so I am getting closer... Seems by removing the #ColumnResult I do get the default mapping, plus the PERMISSION field mapped over! Looks like this:
#SqlResultSetMapping(
name="listPagedMapping"
)
The last issue is it does not accept my CountQuery, and causes my tests to fail whenever a Pagination Query results with multiple pages. Looks like Spring try's to come up with its own CountQuery, which is not correct.
UPDATE: 3
To finish this off, looks like I can provide the Count Query as described here: Spring Data - Why it's not possible to have paging with native query
I will give this a go and update back.
I never got this to work quite how I wanted. I am sure I could by mapping my entire entity, but, that would have been painstaking. I ended up solving this by using NamedNativeQueries, with mapping for the additional Column as a result of my Case statement. My entity class is now annotated like:
#JsonInclude(JsonInclude.Include.NON_NULL)
#SuppressWarnings("unused")
#Data
#AllArgsConstructor
#NoArgsConstructor
#EqualsAndHashCode(callSuper = false)
#Entity
#Table(name = "EC2_PROVISIONING")
#SqlResultSetMappings({
#SqlResultSetMapping(
name = "listPagedMapping",
entities = {
#EntityResult(
entityClass = Ec2Instance.class
)
},
columns = {#ColumnResult(name = "permission", type = String.class)}
),
#SqlResultSetMapping(name = "listPagedMapping.count", columns = #ColumnResult(name = "cnt"))
})
#NamedNativeQueries({
#NamedNativeQuery(
name = "Ec2Instance.listAccessibleInstances",
query = ACCESSIBLE_QUERY,
resultClass = Ec2Instance.class,
resultSetMapping = "listPagedMapping"
),
#NamedNativeQuery(
name = "Ec2Instance.listAccessibleInstances.count",
resultSetMapping = "listPagedMapping.count",
query = ACCESSIBLE_QUERY_COUNT
)
})
We also dont need the permission field in this entity anymore. I removed that.
Then in my Repository:
Page<Object[]> listAccessibleInstances(
#Param("username")final String username,
#Param("instanceStates") final Set<String> instanceStates,
final Pageable pageable);
Thats it! Now the result of my case statement is returned with each entity.
Object[0] = original, default mapped entity.
Object[1] = permission
Related
A many-to-many relationship exists between songs and artists like this:
public class Song {
// ... other fields here
protected Collection<Artist> artists;
#JoinTable(
name = "song_artists",
schema = "playout",
joinColumns = #JoinColumn(name = "song"),
inverseJoinColumns = #JoinColumn(name = "artist"),
foreignKey = #ForeignKey(name = "fk_song_artists_song"),
inverseForeignKey = #ForeignKey(name = "fk_audio_artists_artist")
)
#ManyToMany
public Collection<Artist> getArtists(){
return artists;
}
}
The artist class is a basic Entity
public class Artist {
}
Given a Song x, show songs by any of the artists involved in Song x
, A raw SQL query would be something like this
SELECT * FROM songs WHERE id IN((SELECT song FROM song_artists x WHERE x.artist = ?));
Where '?' would be replaced by a comma separated string of artist IDs involved in the song in question
How can the same result be achieved with JPA (using Hibernate specifically)
Song song = null; // get desired song
Collection<Artist> artists = song.getArtists();
CriteriaBuilder builder = entityManager.getCriteriaBuilder()
CriteriaQuery criteria = builder.createQuery(Song.class);
Root<Song> root = criteria.from(Song.class);
Subquery<Artist> subquery = null; // how to create an appropriate subquery from the join
How can we filter the results here (get more songs by any of the artists in "artists" collection)?
Your feedback will be very much appreciated
Solved it!
In case you face something similar, here's what I did:
Subquery<Artist> subquery = criteria.subquery(Artist.class);
subquery.from(Artist.class);
Join<Audio, Artist> join = subquery.correlate(root.join("artists", JoinType.LEFT));
subquery.select(builder.nullLiteral(Artist.class));
subquery.where(join.in(value.getArtists()));
criteria.select(root).where(
builder.and(
builder.notEqual(root, value), builder.exists(subquery)
)
);
I have a table form_header with 3 records
There are more fields in the table decided not to add it here in the post since most are irrelevant. I created a class/entity to get the count with distinct for each status in sql.
#Entity()
#Table(name = "Form_Header")
#SqlResultSetMapping(name = "myMapping",
entities = {#EntityResult(
entityClass = FormSummary.class,
fields = {#FieldResult(name = "status", column = "status"),
#FieldResult(name = "id", column = "header_id")})})
public class FormSummary {
#Id()
private Long id;
private String status;
<getter and setter>
with entity manager
List<FormSummary> results = entityManager.createNativeQuery("select DISTINCT(status), COUNT(header_id) as header_id from Form_Header where is_deleted = 0 group by status order by status", "myMapping").getResultList();
for (FormSummary x : results) {
System.out.println("ABC " + x.getId());
System.out.println("ABC " + x.getStatus());
}
Issue is the sysout is showing this
instead of this
status header_id
APPROVE 1
DRAFT 1
SUBMITTED 1
Whats even weird is if I add an extra record in the table with the same status
I will get the correct data in my jpa
Am I missing something in my code or a possible bug with SqlResultSetMapping?
I need to retrieve a list of Category from the DB on the basis of value of column called owner. Here is my Category -
#Entity
#Table(name = "categories")
class Category(#Column(name = "category_id", nullable = false)
#Id #GeneratedValue(strategyGenerationType.AUTO)
var id: Long = 0,
#Column(name = "category_owner", nullable = false)
#field:NotNull(message = "Please assign an owner")
var owner: Long?,
#Column(name = "category_name", nullable = false)
#field:NotEmpty(message = "Please assign a name")
var name: String?)
Here is my interface which defines the function findByOwner -
interface CategoryRepository: JpaRepository<Category, Long> {
fun findByOwner(categoryOwner: Long): List<Category>
}
However, when I call the method, I get no response. I have made sure that the DB has correct data and I'm providing the correct owner Id. Have even invalidated the cache etc. What could be going wrong?
EDIT:
After spring.jpa.show-sql=true -
findAll()
Hibernate: select category0_.category_id as category1_0_, category0_.category_name as category2_0_, category0_.category_owner as category3_0_ from categories category0_
findByOwner()
Hibernate: select category0_.category_id as category1_0_, category0_.category_name as category2_0_, category0_.category_owner as category3_0_ from categories category0_ where category0_.category_owner=?
EDIT 2:
Turns out that my implementation was fine all along. The bug was in my service.
Create your named method according with the name of the column.
fun findByCategoryOwner(categoryOwner: Long): List<Category>
Or use #Query
#Query("SELECT * FROM categories WHERE category_owner = ?1", nativeQuery = true)
fun findByOwner(cateogryOwner: Long): List<Category
Can you put a breakpoint in org.springframework.data.jpa.repository.query.JpaQueryExecution class and when you execute findByOwner, it will come here.
When it reaches this breakpoint, select the query.createQuery(accessor).getResultList() and evaluate to see what value is returned by hibernate for spring-data-jpa to use
This post should help you. It appears to be happeing because of the parameter name mismatch.
Use camelCase to name your variables in Entity class then jpa will auto recognise the column name
findByCategoryOwner(String categoryOwner)
If you still wish to have underscore in your column names then try this
findByCategory_Owner(String categoryOwner)
I haven't tried the second option though
At least in java you need to provide the id in the method name:
**fun findByOwner_Id(categoryOwner: Long): List<Category>**
So change it from findByOwner -> findByOwnerId.
I'm using Spring Boot v1.5.3
In my code, I have a search operation with a lot of conditions.
public Page<ParentObject> search(Pageable pageable) {
Specification<ParentObject> specification = (root, cq, cb) -> {
Predicate p = cb.and(
cb.equals(root.get("child").get("id"), "someValue"),
// a lot of predicates appended by conditions
);
return p;
};
Sort newSort = pageable.getSort().and(new Sort(Sort.Direction.ASC, "child.id"));
pageable = new PageRequest(pageable.getPageNumber(), pageable.getPageSize(), newSort)
Page<ParentObject> result = parentObjectRepository.findAll(specification, pageable);
return result;
}
The problem is that my parent table contains child_id field with index. And I want SQL to be like:
SELECT .... FROM parent p INNER JOIN child c ON c.id = p.child_id WHERE ...
ORDER BY p.child_id ASC;
But in result I have:
SELECT .... FROM parent p INNER JOIN child c ON c.id = p.child_id WHERE ...
ORDER BY c.id ASC;
Pay attention to ORDER BY clause. If I have c.id index is not involved and the search is slow. If I have ORDER BY p.child_id it works much faster.
I tried to use
Sort newSort = pageable.getSort().and(new Sort(Sort.Direction.ASC, "child"));
but it does not work as expected.
Entity:
public class ParentObject {
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "child_id", referencedColumnName = "id")
private ChildObject child;
}
I can't replace this by native SQL, because this search specification contains 30+ if/else statements and it will take a lot of time to rewrite the code.
How can I solve this problem? Thanks in advance for your answers.
Finally, I found a solution. As we know, ORM works with database thru entities.
All my entities have String (UUID) values as ids. So, I have added the following code into my ParentObject:
public class ParentObject {
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "child_id", referencedColumnName = "id")
private ChildObject child;
#Column(name = "child_id", insertable = false, updatable = false)
private String childId;
}
As you see, here I have added simple field that contains id of child object. It's important to mark this field as insertable = false, updatable = false and we can't change this field in the code, this is read-only field. But this allows us to sort results by parent.child_id, not by child.id. If we need to replace child object, need just call setChild(newValue).
And finally, my search method now looks like:
public Page<ParentObject> search(Pageable pageable) {
Specification<ParentObject> specification = (root, cq, cb) -> {
Predicate p = cb.and(
cb.equals(root.get("child").get("id"), "someValue"),
// a lot of predicates appended by conditions
);
return p;
};
// IMPORTANT change in next line
Sort newSort = pageable.getSort().and(new Sort(Sort.Direction.ASC, "childId"));
pageable = new PageRequest(pageable.getPageNumber(), pageable.getPageSize(), newSort)
Page<ParentObject> result = parentObjectRepository.findAll(specification, pageable);
return result;
}
And in result I have the following SQL query:
SELECT .... FROM parent p INNER JOIN child c ON c.id = p.child_id WHERE ...
ORDER BY p.child_id ASC;
Hope this would be useful for someone
I set up a Database Application with Spring an Hibernate and I'm using a Many-To-Many-Relationship.
Here's the code:
Author.java
#ManyToMany(cascade = {CascadeType.ALL})
#JoinTable(name = "writes", joinColumns = {#JoinColumn(name = "authorId")}, inverseJoinColumns = {#JoinColumn(name = "publicationId")})
private Set<Publication> publications = new HashSet<Publication>();
Publication.java
#ManyToMany(mappedBy = "publications")
private Set<Author> authors = new HashSet<Author>();
these lines of code generate a connection-table named writes, but when I try to run a query over all Tables int gives me the error, named above.
this is the method, that schould run the query:
#Transactional
public List<Author> findAuthorByLastname(String lastName) {
String hql = "from Author a, Publication p, writes w where a.id = w.authorId and p.id = w.publicationId and a.lastname = :lastName";
Query q = sessionFactory.getCurrentSession().createQuery(hql);
q.setParameter("lastName", lastName);
List<Author> result = q.list();
return result;
}
You don't need to mention connection table explicitly in HQL queries (moreover, you even cannot mention them - only mapped entities). You need to use join on mapped relationships instead.
Also, it's not quite clear what you want to achieve.
If you want to fetch Authors with eagerly filled collections of their Publications in one query, use join fetch:
select distinct(a) from Author a join fetch a.publications where a.lastName = :lastName
If you want to fetch a list of pairs (Author, Publication), use regular join:
select a, p from Author a join a.publications p where a.lastName = :lastName