I am trying to get hibernate to return an object that has the lowest ID number that is greater than a certain value.
The code I have is returning an integer though, instead of the object.
Code
Criteria criteria = session.createCriteria(Story.class);
Criterion storyId = Restrictions.ge("id", 2);
ProjectionList projList = Projections.projectionList();
projList.add(Projections.min("id"));
criteria.add(storyId);
criteria.setProjection(projList);
List<?> storyResult = criteria.list();
session.close();
Story story = (Story) storyResult.get(0);
Right now this is returning "3" as an integer. 3 is the next available ID, but why is hibernate giving me back an integer instead of the object?
Thanks
By adding a Projection, you are essentially asking Hibernate to change your query from SELECT * FROM TABLE to a SELECT MIN(ID) FROM TABLE query. That's one of the features of a projection.
To achieve what you actually want to achieve, you need to use the projection to get the ID and then use another query to retrieve the object.
Criteria idQuery = session.createCriteria(Story.class);
idQuery.add(Restrictions.ge("id", 2));
idQuery.setProjection(Projections.min("id"));
int returnedId = criteria.uniqueResult();
Criteria storyQuery = session.createCriteria(Story.class);
storyQuery.add(Restrictions.idEq(returnedId);
Story story = (Story) storyQuery.uniqueResult();
return story;
Related
In the following criteria query
Criteria criteria = createLogRecordCriteria(maxId, playerId, playerStatus, userCategory, from, to);
criteria.setFirstResult(offset);
criteria.setMaxResults(limit);
criteria.setProjection(Projections.distinct(Projections.property("player")));
List lst = criteria.list();
return lst;
I retrieve only the set of different players , but I need to retireve all entities with different player value. How can it be done through criteria?
Believe this is the query that you are searching for.
For the below query:
select t from Table t
where t.player IN (select distinct t.player
from Table t
);
if DetachedCriteria is a feasible option, the subCriteria can be passed to the mainCriteria written as below (provided that subCriteria should be defined as a DetachedCriteria):
Criteria subCriteria = Criteria.forClass(Table.class);
subCriteria.setProjection(Projections.distinct(Projections.property("player")));
Criteria mainCriteria = createLogRecordCriteria(maxId, playerId, playerStatus, userCategory, from, to);
mainCriteria.add(Property.forName("t.player").in(subCriteria));
//adding the extra restrictions provided in the Question.
mainCriteria.setFirstResult(offset);
mainCriteria.setMaxResults(limit);
List lst = mainCriteria.list();
return lst;
If not, you have to get the result of 'sub-criteria' and then pass the same (in the form of Object[] or Collection) as the parameter to
> mainCriteria.add(Property.forName("t.player").in(Result_Of_subQuery));
Hope this helps.
I need to fetch the result of the following query but i am getting a typecast exception. Kindly help out!
SELECT COUNT(*) FROM ( SELECT DISTINCT a.PROPSTAT_CODE,a.PROPSTAT_DESC,a.PROPSTAT_TYPE FROM CNFGTR_PROPSTAT_MSTR a WHERE 1 = 1 )
My code is given below,
Query query = session.createSQLQuery(sqlQuery);
listRes = query.list();
int ans = ((Integer)listRes.get(0)).intValue();
Thanks in advance
Since you say that you are wrapping the above query in another query that returns the count, then this will give you want, without having to convert to any other data types.
Integer count = (Integer) session.createSQLQuery("select count(*) as num_results from (SELECT DISTINCT a.PROPSTAT_CODE,a.PROPSTAT_DESC,a.PROPSTAT_TYPE FROM CNFGTR_PROPSTAT_MSTR a WHERE 1 = 1)")
.addScalar("num_results", new IntegerType())
.uniqueResult();
System.err.println(count);
The trick is the call to "addScalar". This tells Hibernate you want the data type of "num_results" pre-converted to an Integer, regardless of what your specific DB implementation or JDBC driver prefers. Without this, Hibernate will use the type preferred by the JDBC driver, which explains why different answers here have different casts. Setting the desired result type specifically removes all guesswork about your returned data type, gives you the correct results, and has the added bonus of being more portable, should you ever wish to run your application against a different relational database. If you make the call to "list" instead of "uniqueResult" then you can assign the results directly to a List
Use long instead of int. Hibernate returns count(*) as long not int.
Query query = session.createSQLQuery(sqlQuery);
listRes = query.list();
long ans = (long)listRes.get(0);
Well.. I suppose this should work:
Query query = session.createSQLQuery(sqlQuery);
List listRes = query.list();
int ans = ((BigDecimal) listRes.get(0)).intValue();
Note: you need to import java.math.BigDecimal
List number=session.createSQLQuery("SELECT COUNT(*) FROM devicemaster WHERE ClientId="+id).list();
session.getTransaction().commit();
int ans = ((java.math.BigInteger) number.get(0)).intValue();
i am building a shopping cart using jsp and hibernate.
i am filtering the content by brand size and price using checkboxes
the checked checkboxes are returned to the class where hql query exists.
so i want i single hql query that can handle this.
as like if one of the parameter like size is empty (means user doesnt uses it to filter the content ) than an empty string is passed to the hql query which returns any value...
so is there anything possible that all values can be retrived in where clause for empty string or some other alternative except coding different methods for different parameter...
I typically use the Criteria api for things like this... if the user does not specify a size, do not add it to the criteria query.
Criteria criteria = session.createCriteria(MyClass.class);
if(size != null && !size.isEmpty()){
criteria.add(Restrictions.eq("size", size);
}
To have multiple restrictions via an OR statement, you use Disjunction. For an AND, you use Conjunction.
Criteria criteria = session.createCriteria(MyClass.class);
Disjunction sizeDisjunction = Restrictions.disjunction();
String[] sizes = { "small", "medium", "large" };
for(int i = 0; i < sizes.length; i++){
sizeDisjunction.add(Restrictions.eq("size", sizes[i]);
}
criteria.add(sizeDisjunction );
First, good practices say that instead of passing and empty String to the query, you should pass null instead. That said, this hql should help you:
from Product p
where p.brand = coalesce(:brand, p.brand)
and p.size = coalesce(:size, p.size)
and p.price = coalesce (:price, p.price)
Using Hibernate Criteria i am trying to achieve pagination but the problem is that for every page fetch i have to make two db calls one for results and another for total records count.
Is there any efficient way so that in a single db call i can get both the data or i can reduce db calls.
Criteria criteria=session.createCriteria(Student.class);
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
criteria.add(Restrictions.ne("enquiryStatus", ENQUIRY.JOINED));
criteria.setMaxResults(10);
criteria.setFirstResult((paginate.getStartIndex()-1)*10);
criteria.setProjection(Projections.rowCount());
//here i need to fetch total row count and records
Yes you need the separate query to get the total result count.
Query aCountQuery = session.createQuery("select count(s.id) from Student s
where s.enquiryStatus != :enquiryStatus");
aCountQuery.setParameter("enquiryStatus", ENQUIRY.JOINED);
Long resultCount = (Long)aCountQuery.uniqueResult();
or
Criteria criteria=session.createCriteria(Student.class);
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
criteria.add(Restrictions.ne("enquiryStatus", ENQUIRY.JOINED));
criteria.setProjection(Projections.rowCount())
Long resultCount = (Long)criteria.uniqueResult();
Update
Now you can use same Criteria for results with pagination and result count
Criteria criteria=session.createCriteria(Student.class);
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
criteria.add(Restrictions.ne("enquiryStatus", ENQUIRY.JOINED));
criteria.setMaxResults(10);
criteria.setFirstResult((paginate.getStartIndex()-1)*10);
List<Student> students = criteria.list();
criteria.setProjection(null);
criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
Long resultCount = (Long)criteria.uniqueResult();
As far As I know there is no direct method to do so.As simple as you can do is write a small hql query(my choice) ,Along with your main criteria.
Number count = (Number) session.createQuery(
"select count(s.id) from Student s").uniqueResult();
I make this query:
String query = FROM Account acc WHERE acc.id = ? OR acc.id = ? or acc.id = ?...
I have array of ids:
long[] accountIds= {327913,327652,327910,330511,330643};
Then I make
getHibernateTemplate().find(query, accountIds);
I see that the list of accounts I get back from this query is:
327652,327910,327913,330511,330643, obviously , ordered by id.
Any chance I get it back in the order I wrote the ids?
Will appreciate all the help
You may want to use Criteria and its addOrder.
Something like this:
DetachedCriteria cr = DetachedCriteria.forClass(entityClass);
//Add expressions or restrictions to your citeria
//And add your ordering
cr.addOrder(Order.asc("yourID"));
List<T> ls = getHibernateTemplate().findByCriteria(cr);
return ls;
You can't do it on query level.
You can sort after loading from db, something like this
long[] accountIds= {327913,327652,327910,330511,330643};
List<Account> afterHql = getHibernateTemplate().find(query, accountIds);
List<Account> sortedList = new ArrayList<Acount>();
for (long id : accountIds)
{
for (Account account : afterHql)
{
if (account.getId() == id)
{
sortedList.add(account);
}
}
}
It is not possible to fetch results by providing any entity in OR Query or Restrictions.in(). As by deafult when you fire this kind of query it will search for the results id wise. So it will give you results id wise only. You can change the order by using Criteria either in asc or desc. And if you want to have results as per you enter id, then second answer is the only option.
You can only order by column values returned by the query, in a sequence defined by the data type . Wouldn't it be better to pre-order the IDs you supply, and order the query result by ID, so they come out in the same order?