I am trying using hibernate full text by following this link:
hibernate/search/4.1/reference/en-US/html/getting-started
Basically, it works, but I want to know how to get total count while I execute a full text query,then I can tell user how many results and how many pages would be in such a query.
Here is the code(Using JPA to create and execute a search):
EntityManager em = entityManagerFactory.createEntityManager();
FullTextEntityManager fullTextEntityManager =
org.hibernate.search.jpa.Search.getFullTextEntityManager(em);
em.getTransaction().begin();
// create native Lucene query unsing the query DSL
// alternatively you can write the Lucene query using the Lucene query parser
// or the Lucene programmatic API. The Hibernate Search DSL is recommended though
QueryBuilder qb = fullTextEntityManager.getSearchFactory()
.buildQueryBuilder().forEntity( Book.class ).get();
org.apache.lucene.search.Query query = qb
.keyword()
.onFields("title", "subtitle", "authors.name", "publicationDate")
.matching("Java rocks!")
.createQuery();
// wrap Lucene query in a javax.persistence.Query
javax.persistence.Query persistenceQuery =
fullTextEntityManager.createFullTextQuery(query, Book.class);
persistenceQuery.setFirstResult((page - 1) * PAGECOUNT);
persistenceQuery.setMaxResults(PAGECOUNT);
// execute search
List result = persistenceQuery.getResultList();
em.getTransaction().commit();
em.close();
In SQL, I can use select count(*) from something, but here I don't know how to do that. I want to just fetch one page of data every time and use another API to get total count.
query.getResultSize(); //return the total number of matching ... regardless of pagination
I'm not sure if there is such a way when using the Hibernate full text search.
If you want to know the total number of results then you have to perform the full query. After you have the full count you can set your page limiter and perform it again.
javax.persistence.Query persistenceQuery =
fullTextEntityManager.createFullTextQuery(query, Book.class);
int count = persistenceQuery.getResultList().size();
persistenceQuery =
fullTextEntityManager.createFullTextQuery(query, Book.class);
persistenceQuery.setFirstResult((page - 1) * PAGECOUNT);
persistenceQuery.setMaxResults(PAGECOUNT);
List result = persistenceQuery.getResultList();
For Hibernate(maybe for JPA)
public interface FullTextQuery extends Query
in other words, you need use
org.hibernate.search.FullTextQuery query = fullTextEntityManager.createFullTextQuery(query, Book.class);
instead of
org.hibernate.Query query = fullTextEntityManager.createFullTextQuery(query, Book.class);
and method getResultSize() will be available
When using directly Lucene/Solr, I usually use a hack* by searching for *:*, setting it to return the least possible results BUT that does return the total result count for "everything", and I proceed to extract it. Basically it's the same as the SELECT count(*) FROM whatever :P
*I say hack because I'm not sure if it's supposed to be that way or not, but it works for me...
Related
I try to do the following inside a Spring Boot application : create a native query and page it so it can returns a page of a given number of elements from a #RestController.
Here's the snippet of my code, where em is the #PersistanceContext EntityManager, and the repository method is the following, knowing that queryString is the native query :
Query searchQuery = em.createNativeQuery(this.queryString, MyEntity.class);
List<MyEntity> resultsList = searchQuery.getResultList();
return new PageImpl<>(resultsList, PageRequest.of(index,size), resultsList.size());
My problem is that the Page returned has a content of the complete query result, not a content of the size of size parameter inside the PageRequest.of.
Has anybody faced the same issue and could give a working example on how to paginate a nativeQuery please ?
Thanks for your help
You are mixing Spring Data JPA (Pageable) with JPA EntityManager. You can't do that. If you are already using a native query then simply put the pagination in the query. You can use what your database supports, for example the standard:
SELECT [a_bunch_of_columns]
FROM dbo.[some_table]
ORDER BY [some_column_or_columns]
OFFSET #PageSize * (#PageNumber - 1) ROWS
FETCH NEXT #PageSize ROWS ONLY;
this is example of using native query with pagination:
#Query("SELECT c FROM Customer As c INNER JOIN Offer as f on f.id=c.specialOffer.id inner join User As u on u.id=f.user.id where u.id=?1 And c.status=?2")
Page<Customer> getAllCustomerToShop(Integer shopId,String status,Pageable pageable)
and then you can call it as:
getAllCustomerToShop(shopId,"status",PageRequest.of(index, PAGE_SIZE));
Modify your code as follows
Query searchQuery = em.createNativeQuery(this.queryString, MyEntity.class)
.setFirstResult(pageable.getPageNumber() * pageable.getPageSize())
.setMaxResults(pageable.getPageSize());
I have the following code
#Indexed
#PrimaryKeyColumn(name = "x", ordinal = 1, type = PrimaryKeyType.PARTITIONED)
#Column(value="x")
private String x;
#Indexed
#PrimaryKeyColumn(name = "code", ordinal = 2, type = PrimaryKeyType.PARTITIONED)
#Column(value="code")
private String code;
#Query(value = "select * from customers where code = ?0")
Optional<Customer> findByCode(String code);
When this is executed, I get Caused by: com.datastax.driver.core.exceptions.InvalidQueryException: Cannot execute this query as it might involve data filtering and thus may have unpredictable performance. If you want to execute this query despite the performance unpredictability, use ALLOW FILTERING.
Is there a way to avoid this just from spring-data-cassandra? I do not want to add ALLOW FILTERING in my query. I tried creating a separate index on the code column but this haven't solved the issue. I think it stops in the spring data configuration. If I execute the same query in cqlsh, it works.
You must specify partition key on your query, unless you create index or use ALLOW FILTERING
Executing query with allow filtering might not be a good idea as it can use a lot of your computing resources and Might not return any result because of timeout. Don't use allow filtering in production Read the datastax doc about using ALLOW FILTERING
https://docs.datastax.com/en/cql/3.3/cql/cql_reference/select_r.html?hl=allow,filter
When using a no-sql database, you need to properly design your data to avoid filtering. You can add a secondary index to optimize retrieval by a specific field. More details here: https://docs.datastax.com/en/archived/cql/3.3/cql/cql_using/useSecondaryIndex.html
If you are sure that the query is what you need, you can use the allowFiltering parameter on the #Query annotation to explicitly indicate that ALLOW FILTERING be used.
#Query(value = "select * from customers where code = ?0", allowFiltering = true)
Optional<Customer> findOneByCode(String code);
I am using Criteria API for creation of queries which are usually not using PK as identifier. I am not able to force eclipselink store result to cache.
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Book> criteriaQuery = builder.createQuery(MetadataTextValue.class);
Root<Book> root = criteriaQuery.from(MetadataTextValue.class);
criteriaQuery = criteriaQuery.where(builder.equal(root.get("value"),value.getValue()));
TypedQuery<Book> typedQuery = em.createQuery(criteriaQuery);
MetadataTextValue metadataTextValue = typedQuery.getSingleResult();
But it works for:
Query query = entityManager.createQuery("select m from MetadataTextValue m where m.value = :value");
query.setParameter("value",value.getValue());
return (MetadataTextValue)query.getSingleResult();
So there should not be problem with the entity and value itself. I tried to debug Eclipselink search and when using criteria API, after first cache miss result is added to cache, but next search for same value is again cache miss, but is not added.
There is any way to paginate one Ehcache query from X item to Y item in the index?
Query query = getCache().createQuery();
Attribute<String> did = new Attribute("did");
Attribute<Date> activity = new Attribute("activity");
Attribute<Double> latitude = new Attribute("latitude");
Attribute<Double> longitude = new Attribute("longitude");
query
.addOrderBy(activity, Direction.DESCENDING)
.includeAttribute(did)
.includeAttribute(activity)
.includeAttribute(latitude)
.includeAttribute(longitude)
.includeValues()
.end();
Results results = query.execute();
// To do in query???
List<Result> page = results.range(range * 20, (range + 1) *20);
After call the execute() method, I know the Results.range(int, int) method does it, but I want only get the focus items.
Thank you in advance.
The way you describe is the way to do it.
What you are querying for contains an orderBy clause, so it cannot even be correct without looking at all the results anyway.
Remember also that this is a cache you are dealing with, two queries at different time may return different results as a consequence of expiry or eviction taking place. In this context, trying to get specific range of results across query executions may show duplicate or missed results.
Is this manner a good aproximation to get more performance?
query
.addOrderBy(activity, Direction.DESCENDING)
.includeAttribute(activity)
.includeValues()
.maxResults((range + 1) * 20)
.end();
List<Result> page = query.execute().range(range * 20, (range + 1) * 20);
I use one activity Date property, set when the item is push on cache to avoid the problem exposed by Louis Jacomet previusly.
I am implementing an autocomplete functionality using Jquery, when I type the name, it fetches the record from the db, The records stored in db are mixture of capital & small letters. I have written a HQL Query which fetches me the records with case-sensitive, but I need to records irrespective of case. Here is the query,
List<OrganizationTB> resultList = null;
Query query = session.createQuery("from DataOrganization dataOrg where dataOrg.poolName
like '%"+ poolName +"%'");
resultList = query.list();
Ex : If I have pool names, HRMS Data set, Hrms Data, Hr data etc... if I type HR or hr I need to get all the 3 records, which I'm not able to.
Please help...
change your query to
"from DataOrganization dataOrg where lower(dataOrg.poolName)
like lower('%"+ poolName +"%')"
for more information have a look 14.3 doc
A good solution is:
List<OrganizationTB> resultList = null;
Query query = session.createQuery("from DataOrganization dataOrg where lower(dataOrg.poolName) like lower(:poolName)");
query.setParameter("poolName", '%'+poolName+'%', StringType.INSTANCE);
resultList = query.list();
So you protect your code from SQL injection