Develop Reference

sql to hql throwing exception

I'm using hibernate in my project and I'm trying to convert an existing sql query from DaoImplementation class to hql,
The sql query I have is
JdbcTemplate select = new JdbcTemplate(dataSource);
String sql = "SELECT * FROM (SELECT site_id,rtc,sigplan,cycle_time,health,phase_no,phase_time,active_groups,groupscolour,ip "+
"FROM status_data where rtc>='" + fromDate + "' and rtc<'" + toDate + "' and "+
"site_id=" + SiteId + " order by rtc desc limit "+recordLimit+" )as temp ORDER BY RTC ASC";
I wrote the hql version to get data from HealthLog table as
String hql = " select f from (select h from HealthLog h where rtc>='"+fromDate+"' and rtc <'"+toDate+"' "
+ "and siteId = "+siteId+" order by rtc desc limit "+limit+" ) as f order by rtc asc ";
return super.readListByHql(hql);
But the above hql throws the following exception
org.hibernate.hql.internal.ast.QuerySyntaxException: unexpected token: ( near line 1, column 16 [ select f from (select h from com.traff.hibernate.model.HealthLog as h where rtc>='1974-08-01 14:10:00.0' and rtc <'1974-09-01 23:46:20.6' and siteId = 20 order by rtc desc limit 50000 ) as f order by rtc asc ]
at org.hibernate.hql.internal.ast.QuerySyntaxException.convert(QuerySyntaxException.java:54)
at org.hibernate.hql.internal.ast.QuerySyntaxException.convert(QuerySyntaxException.java:47)
at org.hibernate.hql.internal.ast.ErrorCounter.throwQueryException(ErrorCounter.java:79)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:276)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:180)
at org.hibernate.hql.intern
I also tried the below code snippet but that giving me wrong results
Criteria criteria = createEntityCriteria();
criteria.add(Restrictions.ge("rtc", fromDate));
criteria.add(Restrictions.lt("rtc", toDate));
criteria.add(Restrictions.eq("siteId", siteId));
criteria.setMaxResults(limit);
criteria.addOrder(Order.asc("rtc"));
criteria2 = criteria;
criteria2.addOrder(Order.desc("rtc"));
return criteria2.list();
Which is the correct way to achieve the result?

First of all, as already mentioned in the comments, you cannot do a subquery within the FROM clause in HQL.
See: Hibernate Documentation
Secondly, the limit keyword is not supported by HQL.
Usually you would use query.setFirstResult(0) and query.setMaxResults(recordLimit) methods where query has the type of the Query Interface. But since you are using the limit in a subquery, there is no way.
See: How to set a limit to inner query in Hibernate?
Some options:
Use a native SQLQuery
Since you are only sorting in the outer Query. You could only execute the inner query and sort in Java.
Example for Option 2:
Session session = factory.openSession();
Query query = session
.createQuery("FROM HealthLog "
+ "WHERE rtc >= :rtcL and rtc < :rtcG and siteId = :siteId "
+ "ORDER BY rtc DESC");
query.setParameter("rtcL", fromDate);
query.setParameter("rtcG", toDate);
query.setParameter("siteId", siteId);
query.setFirstResult(0);
query.setMaxResults(recordLimit);
List<HealthLog> res = query.list();
session.close();
Collections.sort(res, new Comparator<HealthLog>() {
public int compare(HealthLog o1, HealthLog o2) {
return o1.getRtc().compareTo(o2.getRtc());
}
});
The query above returns HealthLogs with all attributes. If you want to only retrieve specific attributes, you can add a SELECT new HealthLog(siteId,rtc,sigplan,cycle_time,...) to your Query with a fitting constructor in HealthLog.
Please note that the code snippet might not be ready to use, since i do not know your model and attribute names.

JPA SQLSyntax missing expression error

I have a Java EE application that has a named Query in an entity called download.
The named query is:
#NamedQuery(name="Users.DownloadCount",
query="SELECT u.fullName, count(u.downloads) FROM WebUser u "
+ "JOIN u.downloads ud WHERE ud.downloadTime "
+ "> :startDate AND ud.downloadTime < :endDate")
I attempt to do the following query in one of my methods:
List<Object[]> downloads = new ArrayList();
if(userName==null){
downloads = manager.createNamedQuery("Users.DownloadCount").setParameter("startDate", sDate,TemporalType.DATE)
.setParameter("endDate", eDate,TemporalType.DATE).getResultList();
The date variables sDate and eDate are:
Date sDate = format.parse(startDate);
Date eDate = format.parse(endDate);
For some reason however I seem to be getting a :
java.sql.SQLSyntaxErrorException: ORA-00936: missing expression
exception.
I have pulled the query out of the entity class and done a normal entitymanager query call but I still get the same exception.

Add a blank between ud.downloadTime and > :s and between ud.downloadTime and < !

I realised the problem:
First problem: Missing a group by with the aggregate function
Second problem: Not joining the entities WebUser and Downloads so no way for the function to count the amount of related entities.
Query should be:
"SELECT u.fullName, count(d) FROM WebUser u JOIN u.downloads d "
+ "WHERE d.downloadTime > :startDate AND d.downloadTime< :endDate"
+ " GROUP BY u.fullName"

Hibernate many-to-many retrieve list with condition

Im working with hibernate and java. I have an Group class and a User class. They share a many-to-many relationship as shown in this ERD .
What Im trying to achieve is that I want to retrieve a list of groups with the condition that they contain a User with a certain User_id.
In the GroupDao I have defined a function retrieveForUser in which I tried to retrieve the list using hibernate query language:
public List<Group> retrieveForUser(int userid){
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
String hql = "select distinct g from Group g " +
"join g.allGroupMembers u " +
"where u.id = :id";
Query query = session.createQuery(hql).setResultTransformer(Transformers.ALIAS_TO_ENTITY_MAP);
query.setParameter("id", userid);
List<Group> list = query.list();
session.getTransaction().commit();
return list;
}
When I try to loop throught the resulting list using:
for(Group g : groupDao.retrieveForUser(user1.getId())){
System.out.println(g.getName());
}
I get the following errormessage:
java.lang.ClassCastException: java.util.HashMap cannot be cast to nl.hu.jelo.domain.group.Group
Question
How can I achieve it so that I end up with an List<Group> with only groups that contain a User with an certain User_id

You do not need to set result transformer. ALIAS_TO_ENTITY_MAP is for other purpose.
Simply do
String hql = "select distinct g from Group g " +
"join g.allGroupMembers u " +
"where u.id = :id";
Query query = session.createQuery(hql);
query.setParameter("id", userid);
is good enough.
Something off topic, are you sure you want to handle transaction manually like that?

NamedQuery select first in list

I try to make a namedQuery:
#NamedQuery(name = "Interval.findByMemoryType",
query = "select i from Interval i JOIN i.intervalDatas id "
+ "where id.fragments.memoryType = :memoryType")
My problem is, that fragments is a list of fragment. I'm only interested in memory type of first element in the list.
So I should have something like this:
#NamedQuery(name = "Interval.findByMemoryType",
query = "select i from Interval i JOIN i.intervalDatas id "
+ "(select first(id.fragments)) as fid) where fid.memoryType = :memoryType")
But I get always “The query contains a malformed ending” problem.
Could somebody help me??

You can take the first result:
TypedQuery<Interval> q = em.createQuery ("Interval.findByMemoryType", Interval.class);
q.setParameter("memoryType", memoryType);//+other parameters if you have
Interval interval = q.getSingleResult();
The small disadvantage is that it may load all its intervalDatas (depending on the mapping). Also check the documentation for possible exceptions.

Update with Join hibernate (HQL)

I'm on trouble with an hql problem.
I would like to write a query, that updates an attribut, and that's based on a value on another table.
This is my example, I have those two tables : Client and Widhdrawal.
Client : idClient, name ...
Widhdrawal : idWidh, cost, and the idClient (foreign key)
Now if i would update the client, under the condition of (idClient = 5 for example), i can't.
I tried this, but in vain :
String hql = "UPDATE Widhdrawal W set W.cost = :salary " +
"where W.Client.id_client = :employee_id)";
Query query = session.createQuery(hql);
query.setParameter("salary", 1000);
query.setParameter("employee_id", 5);
int result = query.executeUpdate();
I hope that someone can have some advices, thank you.

Try this:
String hql = "UPDATE Widhdrawal W set W.cost = :salary " +
"where W.idClient = :employee_id)";

Thank you, i found the solution.
I hope that this can help other people ...
This problem is du to lowerCase.
String hql = "UPDATE Widhdrawal W set W.cost= :newCost " +
"where W.client.id_client = :id_cl";
Query query = session.createQuery(hql);

Try this way --
String hql = "UPDATE Widhdrawal W set W.cost = :salary " +
"where W.id_client =(select id_client from client where id_client = :employee_id)";
Widhdrawal and client is POJO class name.