Spring Data JPA Query DSL to relax null parameter - spring-data-jpa

Similar to Handle optional parameters in QueryDSL, I need to change existing Spring Query DSL methods like findByName(String name)
so that the following condition is satisfied
name = :nameParam And (:ownerParam is null OR owner is null OR owner = :ownerParam)
where owner is a new column in the existing entity/table.
Following the Table 2.3. of Supported keywords inside method names
I have changed to findByNameAndOwnerOrOwnerIsNull(String nameParam, String ownerParam) for
name = :nameParam And (owner is null OR owner = :ownerParam)
Though I'm not sure about the precedence of Or, And in query DSL.
Any help on this is more than welcome.
I am using
spring-data-commons-1.6.3.RELEASE.jar
spring-data-jpa-1.4.3.RELEASE.jar
(i)hibernate-entitymanager-4.2.14.SP1-redhat-1.jar, (ii)
hibernate-jpa-2.0-api-1.0.1.Final-redhat-2.jar offered by JBOSS EAP 6.3

Related

Spring JPA findByColumnNameLike not working

I have a method -> findByfileNameLike(fileName,1, pageable) and its declaration in a repository that extends JPA Repository is
#Query(value = QUERY)
#Transactional(propagation = Propagation.REQUIRED, readOnly = true)
#LogExecutionTime
Page<BatchDTO> findByfileNameLike(String
fileName,#Param("departmentId")Integer departmentId, Pageable pageable)
Query is Select new DTO(bdm.id.batch.status) from Table bdm where bdm.id.departmentId =:departmentId and bdm.id.batch.status <> 7";
I want to filter the query by the column fileName.I have read to give the method name as given according to the doc of spring data jpa.But its not working.
Where and how will i give the fileName to be filtered?Should it be first parameter in the method?
Once you specify a query using the annotation #Query, Spring data jpa will not automatically create a query for you based on the method name and it will rely on the query provided by using the annotation.
The method findByfileNameLike will not make any difference here as a query is provided explicitly. Hope that answers your question

Named query with input parameter

I am learning JPA with Hibernate, using maven as well. My problem is How can I use input parameters with UPDATE and SET clause in named query ?
#NamedQuery(name = "updateEmailAddress", query = "Update User u set u.email = :email where u.username = :username")
It gives me an error that a parameter can only be used in the WHERE or HAVING clause. I referred several article but still cannot find the proper solution.
In JPA 2.0 and below, parameters are not allowed in the set clause of a named query; only literals. This limitation is lifted if you are using JPA 2.1.
From what I can gather, you are not using JPA 2.1. Hence, I'll give you a couple of ways to sidestep this limitation.
Option 1:
Use the createQuery method and pass a dynamically generated string to the method.
String queryString = generateQueryString(email, username);
entityManager.createQuery(queryString).executeUpdate();
Option 2:
Update the associated entity and merge.
List<User> result = entityManager.createQuery('select u from user u where
u.username = :username').setParameter('username', username).getResultList();
for (User user : result) {
user.setEmail(email);
entityManager.merge(user);
}
Option 3:
Create the query using HQL not JPQL. I haven't tested this nor do I recommend it because you are going behind the entity manager's back.
Query q = sessionFactory.getCurrentSession().createNamedQuery('updateEmailAddress');
q.setParameter('email', email);
q.setParameter('username', username);
q.executeUpdate();
While in fact until JPA 2.1 this was not allowed, you can actually use it because the providers will let you provide parameters in that way (which turns out to be a good thing!).
It seems the JPA providers are not conforming to the spec regarding this validation, and I think is just because it didn't make any sense (you can see in 2.1 it is now permitted). "Why would me make it difficult do developers?"
I am also using EclipseLink 2.3.1 and it is working fine.
The recommended solution
Just disable Eclipse's JPQL query validation.
If the provider accepts it, you should be fine, otherwise you need to conform to the spec. Very simple. Code will be cleaner and it will conform to recent evaluations of the spec.
Just go to: Preferences > Java Persistence > JPA > Errors/Warnings > Queries and Generators > Invalid or incomplete JPQL queries: and Ignore it
Check this article for details:
Conclusion
Hibernate does not follow the specification on this point but one
might guess that the new version of the JPA-spec will allow this
behavior as indicated by the draft JSR. JBoss Tools is probably
validating the query against the JPQL-grammar which is based on the
specification and is therefore showing a validation error.
And this is the resolution:
End remark
After a discussion in out team we decided to keep the current
implementation despite the breach of specification. Changing the
behavior would mean string concatenation or string substitution to
build the query and the current approach is much cleaner. As we see no
indications of a shift in persistence provider or application server
at this stage we believe the gains of keeping the code are larger than
the risks at this point.
Can you try positional parameter and see if it works?
#NamedQuery(name = "updateEmailAddress", query = "UPDATE User u SET u.email = ?1 WHERE u.username = ?2")
//The parameter needs to be passed as
query.setParameter(1, "the_emailaddress");
query.setParameter(2, "the_username");
You must build a query named as follows:
Query query = getEntityManager().createNamedQuery("updateEmailAddress");
query.setParameter("email", "email#test.com");
query.setParameter("username", "emailuser");
int result = query.executeUpdate();
System.out.println("Rows affected: " + result);
Sources:
Hibernate 3.6 - DML-style operations
hibernate 4.2 - HQL for UPDATE and DELETE
Hibernate Query examples (HQL)
Hibernate Query Languages

Manage #NamedNativeQuery and schema

I have many EntityManager, one per schema that I have (I use entity-mappings file to map EMs with schemas). It works.
When I use #NamedQuery it's working like a charm but when I use #NamedNativeQuery schema is not used. I have to qualify with it SELECT foo FROM schema.table.
Is it the right behaviour ?
I think it's not possible to parameter #NamedNativeQuery to dynamically pass schema (I believe only columns can be dynamics not tables or schemas or anything else) so how can I use #NamedNativeQuery with dynamic schema please ?
Prefix your table name with "{h-schema}", e.g.SELECT foo FROM {h-schema}table
(courtesy of getting hibernate default schema name programmatically from session factory?)
Excerpts from documentation :
NamedNativeQuery : Specifies a named native SQL query. Query names are scoped to the persistence unit.
NamedQuery : Specifies a static, named query in the Java Persistence query language. Query names are scoped to the persistence unit.
It isn't specified directly that NamedNativeQuery is static, but both are same scoped & can't be altered afterwards & it's the desired behaviour.
Named queries are mean to be accessed by multiple modules - application wide, identified by unique name, so they are static & constant. You can try building a query string dynamically & can create a native query from it, instead of named native query.

Ebean generates sql with undercase_notation not CamelCase as expected

I'm setting up a Play! 2 application with an already existing db. The entities have been ported to the new app. When running the application I get a PersistenceException since
the sql generated by ebean uses undercase_notation and not CamelCase as it did in my
previous application. So my restfulIdentifier property becomes restful_identifier_id
instead of restfulIdentifier_id.
I have read the documentation at http://www.avaje.org/ebean/getstarted_props.html but I can't find the settings.
Stack:
PersistenceException: Query threw SQLException:Unknown column 't0.restful_identifier_id'
in 'field list' Bind values:[200926947] Query was: select t0.id c0, t0.name c1, t0.state c2,
t0.restful_identifier_id c3 from company t0 where t0.id = ?
You will have to modify the meta data of the Entity to tell JPA that your columns have a different name now. Either you are using Annotations or XML files. However you need to compile the sources (or at least enahnce it) to get it done.
This is a really old question but Ebean has 2 naming convention implementations - UnderscoreNamingConvention and MatchingNamingConvention ... and MatchingNamingConvention would provide the camel case convention you are after.
So again, the answer would be to do
MatchingNamingConvention namingConvention = new MatchingNamingConvention();
ServerConfig serverConfig = ...
serverConfig.setNamingConvention(namingConvention);

Adding OrderBy clause to a named query

Is it possible to add an OrderBy clause in to JPA Named query at runtime?
Named queries are processed by the persistence provider when the EntityManagerFactory is created. You can't change/modify/append anything about a named query dynamically at runtime.
If you are using JPA 2.0 and you need a way to do high-performance dynamic queries at runtime, you should look into the Criteria API.
From Java EE 5 Documentation : "Is used to specify a named query in the Java Persistence query language, which is a static query expressed in metadata. Query names are scoped to the persistence unit".
As it says, it is static & you can't change the query at runtime.
Rather use custom query or if ordering element is fixed then you can use annotation;
Field:
#OrderBy(value="nickname")
List<Person> friends;
Method:
#OrderBy("nickname ASC")
public List<Person> getFriends() {...};
Even if you can't add order-by clause to your named query, you can provide a parametric orderBy. The following is a perfectly valid query:
SELECT u FROM User u ORDER BY :orderBy
And you are going to change ordering with something like:
query.setParameter("orderBy", "id");