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How to get Page as result in Querydsl query with fetch or fetchResults properly?

Hi what i trying to achieve here is, i want to submit Pageable data into QueryDsl query and get the result as Page, how can i do it properly? here is what i do until now :
here is my controller :
#PostMapping("/view-latest-stock-by-product-codes")
public ResponseEntity<RequestResponseDTO<Page<StockAkhirResponseDto>>> findStockByProductCodes(
#RequestBody StockViewByProductCodesDto request) {
Page<StockAkhirResponseDto> stockAkhir = stockService.findByBulkProduct(request);
return ResponseEntity.ok(new RequestResponseDTO<>(PESAN_TAMPIL_BERHASIL, stockAkhir));
}
in my controller i submit StockViewByProductCodesDto which is looked like this :
#Data
public class StockViewByProductCodesDto implements Serializable {
private static final long serialVersionUID = -2530161364843162467L;
#Schema(description = "Kode gudang yang ingin di tampilkan", example = "GBKTJKT1", required = true)
private String warehouseCode;
#Schema(description = "id dari sebuah branch", example = "1", required = true)
private Long branchId;
#Schema(description = "Kode Branch", example = "JKT", required = true)
private String branchCode;
#Schema(description = "Kode Product yang merupakan kode yang di ambil dari master product", example = "[\"MCM-508\",\"TL-101\"]", required = true)
private List<String> productCodes;
#Schema(description = "Size of row per page", example = "15", required = true)
#NotNull
private int size;
#Schema(description = "Page number", example = "1", required = true)
#NotNull
private int page;
#Schema(description = "Sort by", example = "id", required = false)
private String sort;
}
and here is my service :
public Page<StockAkhirResponseDto> findByBulkProduct(StockViewByProductCodesDto request) {
String warehouseCode = request.getWarehouseCode();
Long branchId = request.getBranchId();
String branchCode = request.getBranchCode();
List<String> productCodes = request.getProductCodes();
Set<String> productCodesSet = new HashSet<String>(productCodes);
Pageable pageable = PageUtils.pageableUtils(request);
Page<StockAkhirResponseDto> stockAkhir = iStockQdslRepository.findBulkStockAkhirPage(warehouseCode, branchId, branchCode, productCodesSet, pageable);
return stockAkhir;
}
as you can see, i extract pageable information with PageUtils.pageableUtils(request), here is my pageableUtils function looked like :
public static Pageable pageableUtils(RequestKeyword request) {
int page = 0;
int size = 20;
if (request.getPage() > 0) {
page = request.getPage() - 1;
}
if (request.getSize() > 0) {
size = request.getSize();
}
if (!request.getSort().isEmpty()) {
return PageRequest.of(page, size, Sort.by(request.getSort()).descending());
} else {
return PageRequest.of(page, size);
}
}
after i got the Pageable data, i submit it into my repository, which is looked like this :
public Page<StockAkhirResponseDto> findBulkStockAkhirPage(String warehouseCode, Long branchId, String branchCode,
Set<String> productCodes, Pageable pageable) {
JPQLQuery<Tuple> query = new JPAQuery<>(em);
long offset = pageable.getOffset();
long limit = pageable.getPageSize();
QStock qStock = QStock.stock;
NumberExpression<Integer> totalQty = qStock.qty.sum().intValue();
query = query.select(qStock.productId, qStock.productCode, totalQty).from(qStock)
.where(qStock.warehouseCode.eq(warehouseCode), qStock.productCode.in(productCodes),
qStock.branchCode.eq(branchCode), qStock.branchId.eq(branchId))
.groupBy(qStock.productId, qStock.productCode);
query.limit(limit);
query.offset(offset);
QueryResults<Tuple> result = query.fetchResults();
long total = result.getTotal();
List<Tuple> rows = result.getResults();
List<StockAkhirResponseDto> stockAkhirDto = rows.stream()
.map(t -> new StockAkhirResponseDto(t.get(0, Long.class), t.get(1, String.class), t.get(2, Integer.class)))
.collect(Collectors.toList());
return new PageImpl<>(stockAkhirDto, pageable, total);
}
there is no error in my editor when viewing this my repository and i able to run my project, but when i execute my repository function, i got this error :
"org.hibernate.hql.internal.ast.QuerySyntaxException: expecting CLOSE,
found ',' near line 1, column 38 [select count(distinct
stock.productId, stock.productCode, stock.warehouseId,
stock.warehouseCode, stock.branchCode, stock.branchId)\nfrom
com.bit.microservices.b2b.warehouse.entity.Stock stock\nwhere
stock.warehouseCode = ?1 and stock.productCode in ?2 and
stock.branchCode = ?3 and stock.branchId = ?4]; nested exception is
java.lang.IllegalArgumentException:
org.hibernate.hql.internal.ast.QuerySyntaxException: expecting CLOSE,
found ',' near line 1, column 38 [select count(distinct
stock.productId, stock.productCode, stock.warehouseId,
stock.warehouseCode, stock.branchCode, stock.branchId)\nfrom
com.bit.microservices.b2b.warehouse.entity.Stock stock\nwhere
stock.warehouseCode = ?1 and stock.productCode in ?2 and
stock.branchCode = ?3 and stock.branchId = ?4]"
the problem is here, on this line :
QueryResults<Tuple> result = query.fetchResults();
when i execute that line, it give me that error, i try to get the fetchResult, because i want to get the .getTotal() for the total.
but if i execute the query with .fetch(), it worked fine, like this :
List<StockAkhirResponseDto> stockAkhirDto = query.fetch()
i got my sql result execute correctly, what did i missed here? how do i get Page result correctly?

Your problem could be related with an open QueryDSL issue. The documented issue has to do with the use of fetchCount but I think very likely could be also your case.
Consider the following comment in the mentioned issue:
fetchCount() uses a COUNT function, which is an aggregate function. Your query already has aggregate functions. You cant aggregate aggregate functions, unless a subquery is used (which is not available in JPA). Therefore this use case cannot be supported.
The issue also provides a temporary solution.
Basically, the idea is be able to perform the COUNT by creating a statement over the initial select. AFAIK it is not possible with QueryDsl and this is why in the indicated workarounds they access the underline mechanisms provided by Hibernate.
Perhaps, another thing that you can try to avoid the limitation is to create a database view for your query, the corresponding QueryDsl objects over it, and use these objects to perform the actual computation. I am aware that it is not an ideal solution, but it will bypass this current QueryDsl limitation.

JPA - find by multiple attributes in collections of objects

I have an event object with following attributes:
class Event {
String name;
String location;
LocalDateTime date;
String description;
}
Lets say I get from web API a list of events:
List<Events> events = getEvents(); // e.g. 5 events
And now I want to check how many of these events I already have in my DB.
Event is unique if combination of values: name, location and date is also unique.
So basically I want to a create query to do this:
Optional<Event> getByNameAndLocationAndDate(String name, String location, LocalDate date);
but for a list of item in just one query. Something like:
Optional<Event> getByNameAndLocationAndDate(List<Events> events);
Is it possible with JPA?

There is no built-in or specially pretty way of doing this. But you could generate a query by using a loop:
public List<Event> getByNameAndLocationAndDate(List<Event> events) {
if (events.isEmpty()) {
return new ArrayList<>();
}
final StringBuilder queryBuilder = new StringBuilder("select e from Event e where ");
int i = 0;
for (final Event event : events) {
if (i > 0) {
queryBuilder.append("or")
}
queryBuilder.append(" (e.name = :name" + i);
queryBuilder.append(" and e.location = :location" + i);
queryBuilder.append(" and e.date = :date" + i + ") ");
i++;
}
final TypedQuery<Event> query = em.createQuery(queryBuilder.toString());
int j = 0;
for (final Event event : events) {
query.setParameter("name" + j, event.getName());
query.setParameter("location" + j, event.getLocation());
query.setParameter("date" + j, event.getDate());
}
return query.getResultList();
}
Like I said, not very pretty. Might be better with criteria API. Then again, unless you have very strict requirements for execution speed, you might be better off looping through the list checking one event at the time. It will result in the more queries run against the database, but also much prettier code.
Edit: Here is attempt using criteria API, haven't used it much so created just by googling, no guarantee it works as it is..
public List<Event> getByNameAndLocationAndDate(List<Event> events) {
if (events.isEmpty()) {
return new ArrayList<>();
}
final CriteriaBuilder cb = em.getCriteriaBuilder();
final CriteriaQuery<Event> query = cb.createQuery(Event.class);
final Root<Event> root = query.from(Event.class);
final List<Predicate> predicates = new ArrayList<>();
final List<Predicate> predicates = events.stream().map(event -> {
return cb.and(cb.equal(root.get("name"), event.getName()),
cb.equal(root.get("location"), event.getLocation()),
cb.equal(root.get("date"), event.getDate()));
}).collect(Collectors.toList());
query.select(root).where(cb.or(predicates.toArray(new Predicate[]{})));
return em.createQuery(query).getResultList();
}

try
List<Event> findByNameInAndLocationInAndDateIn(List<String> names,List<String> locations,List<Date> dates);
but this returns a list, not a single event, if you need verify if one event is not in database, the only way to do this is search one by one,
you can use this function for decide if needs that.
I'm not sure if this function behaves as you wish

Spring Hibernate generate dynamic query

I am using hibernate spring where I need to generate query on a condition.
DAO.java
public ReturnData updateUserDetails(Users users, String mailID)
{
if(!users.getImageURL().equals(""))
{
Query query = this.sessionFactory.getCurrentSession().createQuery("UPDATE users SET emailID=:email_ID, name=:name, imageURL=:imageURL WHERE emailID=:emailID")
//setString....
}
else
{
Query query = this.sessionFactory.getCurrentSession().createQuery("UPDATE users SET emailID=:email_ID, name=:name WHERE emailID=:emailID")
//setString....
}
}
In the above code, I check if image also has been uploaded or not. On the basis of this condition, I have to dynamically generate query. I have to rewrite the whole code for query+execution 2 times. Is it the good way, or is there any better way to do this?

You can dynamically append the query conditions to the query string if they are not null. After getting the final list of conditions, you can create Hibernate query.
StringBuilder sqlQuery = new StringBuilder();
Map<String,Object> parameters = new HashMap<String,Object>();
boolean isFirstSearchCriterion = true;
sqlQuery.append("UPDATE users");
if(email_ID!= null && !email_ID.trim().equals("")) {
if(isFirstSearchCriterion) {
sqlQuery.append(" set emailID= :email_ID");
} else {
sqlQuery.append(" and emailID= :email_ID");
}
parameters.put("email_ID",email_ID);
isFirstSearchCriterion = false;
}
if(name!= null && !name.trim().equals("")) {
if(isFirstSearchCriterion) {
sqlQuery.append(" set name= :name");
} else {
sqlQuery.append(" and name= :name");
}
parameters.put("name",name);
isFirstSearchCriterion = false;
}
if(imageURL!= null && !imageURL.trim().equals("")) {
if(isFirstSearchCriterion) {
sqlQuery.append(" set imageURL= :imageURL");
} else {
sqlQuery.append(" and imageURL= :imageURL");
}
parameters.put("imageURL",imageURL);
isFirstSearchCriterion = false;
}
Query query = this.sessionFactory.getCurrentSession().createQuery(sqlQuery);
Set<String> parameterSet = parameters.keySet();
for (Iterator<String> it = parameterSet.iterator(); it.hasNext();) {
String parameter = it.next();
query.setParameter(parameter, parameters.get(parameter));
}

You can simply do without checking empty String, if user has image url it will add in column or else empty url will be pass on.
public ReturnData updateUserDetails(Users users, String mailID)
{
Query query = this.sessionFactory.getCurrentSession().createQuery("UPDATE users SET emailID=:email_ID, name=:name, imageURL=:imageURL WHERE emailID=:emailID")
query.setParameter("imageURL",users.getImageURL(), Hibernate.STRING);
}

Complex query in Morphia

in my method Java,
I would like to pass as a parameter to my collection MongoDB a complex query like this one:
{"$or": [{"$and": [{"contextID": "AKKA"}, {"messageID": "PIPPO"}]},
{"$and": [{"domain": "Niguarda"}, {"hostName": {"$ne": "hostServer"}}]}
]
}
The string that contains the query is variable and passed as parameter in query string.
I tried to pass the query as parameter to method criteria
(queryDB.criteria("
{"$or": [
{"$and": [{"contextID": "AKKA"}, {"messageID": "PIPPO"}]},
{"$and": [{"domain": "Niguarda"}, {"hostName": {"$ne": "hostServer"}}]}]
}"
)
but it does not work.
Any suggestions?

What you're trying to do would be
Query q = dao.createQuery();
q.or(
q.and(new Criteria[]{ dao.createQuery().filter("contextID").equal("AKKA"),
dao.createQuery().filter("messageID").equal("PIPPO") }),
q.and(new Criteria[]{ dao.createQuery().filter("domain").equal("Niguarda"),
dao.createQuery().filter("hostname").notEqual("hostServer") })
);

This is now the code (it's works fine but I abandoned morphia):
public long count(String query) throws Exception {
DB db = mongoClient.getDB(mongoDBName);
DBCollection dbCollection = db.getCollection(mongoDBCollection);
DBObject dbObjQuery;
long l = 0;
try {
if (!(query == null)) {
dbObjQuery = (DBObject) JSON.parse(query);
l = dbCollection.find(dbObjQuery).count();
} else {
l = dbCollection.find().count();
}
} catch (Exception e) {
} finally {
}
return l;
}
There is another way to do this with morphia?

How can I retrieve multiple objects with JPA?

I'm using JPA2/hibernate with this data model:
class Stock {
#ManyToOne
private StockGroup stockGroup;
private boolean visible;
}
class StockGroup {
#OneToMany(mappedBy = "stockGroup")
private List<Stock> stocks;
}
I would like to retrieve StockGroup's containing Stock's where visible==true.
I've come up with this faulty code:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<StockGroup> q = cb.createQuery(StockGroup.class);
Root<StockGroup> r = q.from(StockGroup.class);
Join<StockGroup, Stock> j = r.join(StockGroup_.stocks, JoinType.INNER);
Predicate p = cb.equal(j.get(Stock_.visible), true);
// This becomes a cartesian product :(
List<StockGroup> l = em.createQuery(q.where(p)).getResultList();
// Stocks are not filtered on visible :(
l.get(0).getStocks();
Is it possible to retrieve the StockGroup and Stock Objects with one CriteriaQuery or can JPA only fill one type at once? Or can i add some Criteria when .getStocks() is filled lazily?

The trick to doing this is returning a tuple containing an old-fashioned join between the Stock and the StockGroup, like this:
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Tuple> q = cb.createQuery(Tuple.class);
Root<Stock> sRoot = q.from(Stock.class);
Root<StockGroup> sgRoot = q.from(StockGroup.class);
q.select(cb.tuple(sRoot, sgRoot)).where(
cb.and(cb.equal(sRoot.get(Stock_.stockGroup), sgRoot),
cb.isTrue(sRoot.get(Stock_.visible))));
List<Tuple> l = em.createQuery(q).getResultList();
The tuple is then not fully type safe, but you can reach it by position (or by alias, if you've given your select expressions or roots an alias):
for (Tuple t : l) {
Stock s = (Stock) t.get(0);
StockGroup sg = (StockGroup) t.get(1);
System.out.println("Stock is : " + s + " .... StockGroup: " + sg);
}
There's a good article on IBM DeveloperWorks on JPA2 Typesafe Queries.
Good luck in your JPA2 endeavors!