How can we implement the Hibernate sqlprojection in my query?
Here is my query
SELECT sum(total_amount) as total,created_at from order where created_at < DATE_SUB(curdate(), INTERVAL 7 DAY) and doctor_id = 193 GROUP BY created_at
I have implement DATE_SUB function using sqlRestriction like this:
String sqlWhere = "created_at > DATE_SUB(curdate(), INTERVAL "+activityGraph+" DAY) AND doctor_id = "+id +" GROUP BY created_at";
Criteria criteria = Hibernatesession.createCriteria(Order.class);
criteria.add(Restrictions.sqlRestriction(sqlWhere));
But I don't know how I get the sum of a field using Hibernate query.
I found out that setProjection in Hibernate is used to get the sum as we desired but I don't know how to use it. Also here I want to use sqlRestriction to write WHERE condition for date_sub function.
So I will use setProjection and sqlRestriction in a single query.
You're making you life difficult. Why don't you simply compute the date limit in Java before executing the query?
Date today = DateUtils.truncate(new Date(), Calendar.DATE);
Date limit = DateUtils.addDays(today, -7);
And since the query is completely static, why using the Criteria API. HQL is much easier:
String hql = "SELECT sum(o.totalAmount) as total, o.createdAt from Order o"
+ " where o.createdAt < :limit"
+ " and o.doctor.id = 193"
+ " group by o.createdAt";
criteria.setProjection((Projections.sum("/* name of the mapping variable for total_amount*/")));
public int getSum() {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
Criteria criteria = session.createCriteria(Product.class);
criteria.setProjection(Projections.sum("productCount"));
List list = criteria.list();
session.getTransaction().commit();
return (int) list.get(0);
}
//hibernate mpping
<property name="productCount" type="int" column="PRODUCT_COUNT"/>
Related
I want to add a value to an existing column, but I don't want to have to select it first. Right now I would have to do something like
// run hql in a named query
from Employee where id = :id
// after running the above
e.setBonus(e.getBonus() + 100); // add 100 to e's bonus
// commit to database
HibernateUtil.saveOrUpdate(e);
But I want something that's just one-and-done - something like
update Employee e set e.bonus = e.bonus + 100
Is this something I can do in Hibernate? If so, how. If not, what's the suggested best practice for such an update?
You could create a hql query that just does an update
Query updateBonus = createQuery("UPDATE Employee SET bonus = bonus+100 WHERE id = :id" );
updateBonus.setInteger("id", employee.getId());
updateBonus.executeUpdate();
Yes, you can do it as intended with hql query. Try such code:
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
String hql="update Employee e set e.bonus = e.bonus + :p where id=:id";
session.createQuery(hql).setInteger("p",100).setInteger("id",id).executeUpdate();
tx.commit();
session.close();
More info you can find by the link
I want to count elements from table using NamedQueries.
NamedQuery is:
#NamedQuery(name = Advertisement.countBySubcategoryList, query = "select count(*) from Advertisement where subcategoryId IN (:subcategoryId)")
and:
public static final String countBySubcategoryList = "Advertisement.countBySubcategoryList";
In model I use:
List<Advertisement> advertisements = session.getNamedQuery(Advertisement.countBySubcategoryList)
.setParameterList("subcategoryId", subcategoryIds)
.list();
How to get count value from query?
Your query should be something like
select count(a) from Advertisement a where a.subcategoryId IN (:subcategoryId)
And you should call it like this
Long count = (Long)session.getNamedQuery(Advertisement.countBySubcategoryList)
.setParameterList("subcategoryId", subcategoryIds)
.uniqueResult();
EDIT
Hibernate versions prior to 4 returned Integer instead of Long for this type of query.
You can even try this, if you are hibernate version < 4
int count =
((Number)em.createNamedQuery("Advertisement.countBySubcategoryList").getSingleResult()).intValue();
if you are hibernate version >= 4 . #Maric is right
Long count =
(Long)session.getNamedQuery(Advertisement.countBySubcategoryList)
.setParameterList("subcategoryId", subcategoryIds)
.uniqueResult();
Below is mysql query which is working fine and giving me expected results on mysql console.
select * from omni_main as t where t.date_time BETWEEN STR_TO_DATE(CONCAT('2011', '08', '01'),'%Y%m%d') AND LAST_DAY(STR_TO_DATE(CONCAT('2012', '08','01'), '%Y%m%d')) group by year(date_time),month(date_time)
I need its JPA equivalent query. Below is what I am trying but its returning nothing.
String queryStr = "select * from OmniMainEntity o where o.dateTime BETWEEN STR_TO_DATE(CONCAT('"+fromYear+"', '"+fromMonth+"','01'), '%Y%m%d') AND "
+"LAST_DAY(STR_TO_DATE(CONCAT('"+toYear+"', '"+toMonth+"','01'), '%Y%m%d'))";
Query query = manager.createQuery(queryStr);
System.out.println("Result Size: "+query.getResultList().size());
Here fromYear, fromMonth, toYear, toMonth are method parameters using in creating queryStr.
Please suggest where I may wrong!
Any other way to achieve goal is also welcome!
As you are using JPA Query, it would be better to not use database-specified sql function, such as STR_TO_DATE.
You can have a try by this way.(A Hibernate way, JPA should be similiar):
First, you can parse a java.util.Date object from "fromYear" and "fromMonth" like below:
DateFormat df = new SimpleDateFormat("yyyyMMdd");
Date startDate = df.parse(fromYear + "" + fromMonth + "01");
Date endDate = df.parse(.....);
Then, set them into the JPA query.
String queryStr = "select * from OmniMainEntity o where o.dateTime BETWEEN :startDate AND :endDate)"; // The query now changed to database independent
Query query = manager.createQuery(queryStr);
query.setDate("startDate", startDate);
query.setDate("endDate", endDate);
At last, doing the search:
System.out.println("Result Size: "+query.getResultList().size());
Your query doesn't have a verb in it. You probably want SELECT in there:
SELECT o FROM OmniMainEntity o WHERE...
Also, you should be using parameterized and typed queries, and it's usual to use short names (o instead of omniMainEnt) to make your queries readable.
I want to write a method that returns a list of last added objects grouped by field 'serviceId'.
The following HQL works, but I want to write this using Criteria API:
FROM Notification WHERE date IN
(SELECT MAX(date) FROM Notification GROUP BY serviceId)
ORDER BY date ASC
Something like this:
Criteria crit = session.createCriteria(Notification.class);
crit.add(Restrictions.in("date", <MAX dates>));
criteria.addOrder(Order.desc("date"));
Thanks in advance.
EDIT:
Now I need a similar query that works using eclipselink API =/
Basically, I need the last N rows (max date), which status is one of the five described bellow, grouped by serviceId column.
Due to my inexperience, it was the best I could:
ExpressionBuilder builder = new ExpressionBuilder();
Expression exStatus1 = builder.get("status").equal(MessageType.START.toString());
Expression exStatus2 = builder.get("status").equal(MessageType.RUNNING.toString());
Expression exStatus3 = builder.get("status").equal(MessageType.PAUSED.toString());
Expression exStatus4 = builder.get("status").equal(MessageType.END_ERROR.toString());
Expression exStatus5 = builder.get("status").equal(MessageType.END_SUCCESS.toString());
ReadAllQuery query = new ReadAllQuery();
query.setReferenceClass(Notification.class);
query.setSelectionCriteria(((exStatus1).or(exStatus2).or(exStatus3).or(exStatus4).or(exStatus5)));
query.setMaxRows(listSize);
query.addDescendingOrdering("date");
The clause to avoid duplicates serviceIds in result rows is missing...
You're going to want to use the Criteria projections API with a detached subquery:
Criteria crit = session.createCriteria(Notification.class, "main");
DetachedCriteria notificationSubQuery = DetachedCriteria.forClass(Notification.class, "sub");
notificationSubQuery.setProjection(Projections.max("date"));
notificationSubQuery.add(Restrictions.eqProperty("sub.serviceId", "main.serviceId"));
crit.add(Subqueries.propertyIn("date", notificationSubQuery));
crit.addOrder(Order.desc("date"));
This mirrors the technique you are using in your HQL query.
EDIT:
I updated the query to match serviceId between your main notification class and your sub query, essentially the same as this HQL Query:
FROM Notification main WHERE date IN
(SELECT MAX(sub.date) FROM Notification sub WHERE sub.serviceId = main.serviceId)
ORDER BY date ASC
This prevents the case where you would have a non-maximum date matching between two different serviceIds like so:
serviceId = 1: date = 3,4,5
serviceId = 2: date = 4,5,6
Old query return:
serviceId: 1, date: 5
serviceId: 2, date: 5,6
New query return:
serviceId: 1, date: 5
serviceId: 2, date: 6
Let me know if this works for you.
When I try to execute the following HQL query:
Query query = getSession().createQuery("update XYZ set status = 10");
query.executeUpdate();
I get this exception:
Exception in thread "main" org.hibernate.QueryException: query must begin with SELECT or FROM: update
EDIT:
I also tried following .But it doennot work either.
org.hibernate.Query query = getSession().createQuery("update XYZ t set t.status = 10");
EDIT2:
Making changes in hinbernate.cfg.xml solved my problem
Earlier i was using
setting hibernate.query.factory_class" = org.hibernate.hql.classic.ClassicQueryTranslatorFactor
Now am using following property
<property name="hibernate.query.factory_class">org.hibernate.hql.ast.ASTQueryTranslatorFactory</property>
Thats not an HQL query.
You want to import javax.persistence.Query which allows normal sql,
not org.hibernate.Query which works on entity objects.
If you want to use simple sql, you could also use PreparedStatement
However, if you really want to use hibernate, without taking advantage of entityobjects (totally defeating the point of using hibernate in the first place, imho) you could do it like this (reference docs):
String myUpdate = "update XYZ myAlias set myAlias.status = :newStatus";
// or String noAliasMyUpdate = "update XYZ set status = :newStatus";
int updatedEntities = getSession().createQuery(myUpdate) //or noAliasMyUpdate
.setInt( "newStatus", 10 )
.executeUpdate();
The question is thinking in SQL, when you should be thinking in objects:
XYZ xyz = new XYZ();
xyz.setStatus(10);
getSession().merge(xyz);
Try:
Query query = getSession().createQuery("update XYZ o set o.status = 10");
query.executeUpdate();
Take a look at this also.
Session sesssion = getSession(); //getter for session
For HQL :
String hql = "update Activity " +
"set startedOn = :taskStartedOn " +
"where id = :taskId";
Query query = session.createQuery(hql);
query.setDate("taskStartedOn",new Date());
query.setLong("taskId",1)
int rowCount = query.executeUpdate();
Here Activity is POJO.
Use
hibernate.query.factory_class = org.hibernate.hql.ast.ASTQueryTranslatorFactory
in hibernate.cfg.xml file to resolve exception:
org.hibernate.QueryException: query must begin with SELECT or FROM: update.....