How to pass where clause whitout using query dsl or custom repository?
public interface PlTransactionsRepository extends PagingAndSortingRepository<PlTransactions, Integer>, JpaSpecificationExecutor<PlTransactions> {
#Query(value = "SELECT a FROM PlTransactions :whereClause")
List<PlTransactions> selectTrxForRecon(#Param("whereClause") Integer whereClause);
}
For dynamic where queries, you shouldn't use JPQL but Criteria API or the Spring Data JPA JpaSpecificationExecutor
If you implement JpaSpecificationExecutor you'll get find methods where you can pass a Specification. A Specification will form the dynamic where clause.
Please find more information in the documentation:
https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#specifications
Related
I am trying to make a specific query in a MongoDB collection with SpringBoot. There are lots of results with the query that can be seen here. I am trying to sort and filter the results as I did in MongoDB compass in the screenshot and get ONLY the latest entry in the query results.
TaskRepo.java
public interface TaskRepo extends MongoRepository<Task, String> { }
MongoRepository help you to query document with attributes of resource (entity), when you want to query with attributes of sub-resource (embedded entity) you can use #Query to declare finder queries directly on repository methods
public interface TaskRepo extends MongoRepository<Task, String> {
#Query("{'meta.idf' : ?0, 'method': ?1}).sort({'meta.date': -1}")
public List<Task> findBySubResourceAndSort(String id, String method);
}
Or you can use MongoTemplate (refer this document https://docs.spring.io/spring-data/mongodb/docs/current/api/org/springframework/data/mongodb/core/MongoTemplate.html)
I have an entity, which has multiple(lets say more than 5) fields in it. I want to list only 2 of the fields in entity. I managed to do it with Entity Manager and JPA Query. In the code below, I added how I did it with entity manager, but it may not be optimal solution. What I want to ask is, can I do that with using the EntityGraph?
List<Object[]> test = entityManager.createQuery("SELECT c.a, c.b FROM TestClass c WHERE c.id = :id", Object[].class)
.setParameter("id", id)
.getResultList();
TestClassResult testClassResult = new TestClassResult();
for (Object[] row : test) {
testClassResult.setA((BigDecimal) row[0]);
testClassResult.setB((BigDecimal) row[1]);
}
As far as I know, an implementation is allowed to fetch only what you specify when registering an entity graph as fetch graph (different from a load graph), but at least Hibernate does not support this.
Anyway, DTO projections are usually the way to in such a case anyway and I think this is a perfect use case for Blaze-Persistence Entity Views.
I created the library to allow easy mapping between JPA models and custom interface or abstract class defined models, something like Spring Data Projections on steroids. The idea is that you define your target structure(domain model) the way you like and map attributes(getters) via JPQL expressions to the entity model.
A DTO model for your use case could look like the following with Blaze-Persistence Entity-Views:
#EntityView(TestClass.class)
public interface TestClassResult {
#IdMapping
Integer getId();
BigDecimal getA();
BigDecimal getB();
}
Querying is a matter of applying the entity view to a query, the simplest being just a query by id.
TestClassResult a = entityViewManager.find(entityManager, TestClassResult.class, id);
The Spring Data integration allows you to use it almost like Spring Data Projections: https://persistence.blazebit.com/documentation/entity-view/manual/en_US/index.html#spring-data-features
Page<TestClassResult> findAll(Pageable pageable);
The best part is, it will only fetch the state that is actually necessary!
as far as I know, entity graphs define which attributes to fetch from the database so you can fetch the 2 attributes eagerly and the other 3 lazily, "Thorben Janssen" has a good article on his website about graphs, another way to exclusively fetch selected attributes is to use DTO Projections, he also does have a good article touching the subject.
I was doing a project and there i had a requirement of using pageable object and recieved page object from JPA.
Does anyone have any idea on how to use this?
#Repository
public interface CustomerRepository extends JpaRepository<Customer,Long>{
#Query("SELECT * FROM WHERE name=?1 AND surname=?2 ", nativeQuery = true)
List<Customer> findAllByNameAndSurname(String name,String surname);
}
I want a page List for result fetch from this query.
Spring Data JPA and native queries with pagination is not supported in Spring. According to documentation , Spring Data JPA repositories can be used with native queries and pagination. But, in real life Spring Data JPA (1.10.2.RELEASE) requires some additional fix.
You have to use this if you want pagination support.
List<Customer> customers = customerRepository.findAllByNameAndSurname(name,username);
PagedListHolder<Customer> pages = new PagedListHolder(customers);
pages.setPage(currentPageNumber); //set current page number
pages.setPageSize(pageSize); // set the size of page
pages.getPageList(); // return the list of items(or in your case List<Customer> ) of current page
Try this:
#Repository
public interface CustomerRepository extends JpaRepository<Customer, Long> {
Page<Customer> findAllByNameEqualsAndSurnameEquals(String name, String surname, Pageable pageable);
}
I am pretty sure JpaRepository can handle your Pageable parameter.
Also, method name has to be as I mentioned as spring creates queries based on method name (uses reflection).
If you really need to execute NATIVE QUERY you will have to find other solution but I do not recommend the one provided by Dasari Swaroop Kumar as it just queries all objects from database and then kinda filters it in memory.
Also to that native query solution - you can extend your method definition to additional 2 parameters for page and pageSize and append them to your native query and leave repository to return plain List and then create PageImpl object in the layer that calls your CustomerRepository object.
The #Query annotation supports only JPA query syntax or Hibernate (HQL)? or both of them i am kinda confused
interface TodoRepository extends CrudRepository<Todo, Long> {
#Async
#Query("SELECT t.title FROM Todo t where t.id = :id")
Book<String> findTitleById(#Param("id") Long id);
SpringData repositories support JPQL (Java Persistence Query Language).
Though JPQL is a subset of HQL so any JPQL query is a valid HQL query.
The inverse is obviously not true.
I am new to SpringData and I am not getting what is happening here. I have created an Interface that extends PagingAndSortingRepository and overrided the findAll() method like this:
#Override
#Query
List<MyEntity> findAll();
I am calling this method in my service, but it is making my app to throw an exception Caused by: java.lang.StackOverflowError because that method is reading through the entire database, not only from MyEntitytable in database. Any idea?
Apparently the problem is in the configuration of EclipseLink. In persistence.xml I added this row <shared-cache-mode>NONE</shared-cache-mode> and now it works as it should.
no need to override getall() method.in your service autowired that dao or repository class and using this you can directly call the findall() method.
in the case you want to write your custom method apart from what given by spring data jpa then we use the #Query to write custom query.
No Need to Override. What i have done is i have created a repository i.e
FavoriteRepository which is extending JpaRepository and i have mentioned the
dbmodel name (Favorite)
like this JpaRepository<Favorite, Long> // Here Favorite is my model name
and Long is the type of primary key mentioned in db model Favorite as #Id
#Repository
public interface FavoriteRepository extends JpaRepository<Favorite, Long>{
}
Now you can use method findOne or findAll. As these methods are present in
Jparepository.Hope so it will help
If you want to add new method then use #Query with JpQL
#Query(value = "select f from Favorite f where f.userId=:userId ")
public List<Favorite> getFavoritesForUser(#Param("userId") String userId);