I've tried to do it like:
session = HibernateUtil.getSessionFactory().openSession();
Criteria cr = session.createCriteria(Car.class);
cr.createAlias("vendor", "vendor");
cr.add( Restrictions.eq("vendor.name", input));
results = (List<Car>) cr.list();
And also like:
session = HibernateUtil.getSessionFactory().openSession();
Criteria cr = session.createCriteria(Car.class);
cr.createCriteria("vendor").add(Restrictions.eq("name", input));
results = (List<Car>) cr.list();
Both realizations just return all data, not specified with search query.
In the Car Class I've got relationship:
#ManyToOne(fetch=FetchType.LAZY)
#JoinColumn(name="id_vendor", nullable=false)
public Vendor getVendor() {
return this.vendor;
}
And also I've got thename column at the Vendor class at which I'm trying to search.
So how possibly I could do such search request?
Thanks.
You need to assign your criteria back to the original object.
The reason you get all the cars back is because the line of code adding your vendor into the query creates you a new criteria object which you are then not using.
Change:
session = HibernateUtil.getSessionFactory().openSession();
Criteria cr = session.createCriteria(Car.class);
cr.createCriteria("vendor").add(Restrictions.eq("name", input)); //Does nothing
results = (List<Car>) cr.list();
into this:
session = HibernateUtil.getSessionFactory().openSession();
Criteria cr = session.createCriteria(Car.class);
cr = cr.createCriteria("vendor").add(Restrictions.eq("name", input));
results = (List<Car>) cr.list();
And it should work.
if you wont get unique result of Car.class you nedd set ResultTransformer
Criteria cr = session.createCriteria(Car.class);
cr.createAlias("vendor", "vendor");
cr.add( Restrictions.eq("vendor.name", input));
crit.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
results = (List<Car>) cr.list();
Related
session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
String hql ="from CustomObjectId where CONTAINS(fileName,fileName)";
Query query = session.createQuery(hql);
query.setParameter("fileName", fileName);
List file=query.list();
tx.commit();
How can I search CONTAINS?
You need to use IN clause as shown below:
session = sessionFactory.openSession();
String hql =" from CustomObjectId c where c.fileName in :fileName";
Query query = session.createQuery(hql);
query.setParameter("fileName", fileName);
List file=query.list();
Also, you DO NOT need a transaction (explicitly) to only READ from database. So, just remove Transaction tx = session.beginTransaction(); and tx.commit(); lines.
You can do that with Hibernate Criteria.
String fileNames[] = {"fileName1", "fileName2"};
session = sessionFactory.openSession();
Criteria criteria = session.createCriteria(CustomObjectId.class);
criteria.add(Restrictions.in("fileName ", fileNames));
List list = criteria.list();
I have a method like below
public List<String> getSimilarResourceNames(String resourceName){
String searchString = "%"+resourceName+"%";
Session session = getSession();
Criteria criteria = session.createCriteria(Resource.class);
criteria.add(Restrictions.like("name", searchString));
return criteria.list()
}
This will return me the entire resource from the DB, but what i need is just the name of the resource. How can I accomplish that ?
Use Projection, you can find examples in Hibernate documentation.
Criteria criteria = session.createCriteria(Resource.class);
criteria.setProjection(Property.forName("name"))
criteria.add(Restrictions.like("name", searchString));
By using Projection you will get other fields (Which you did not got by Projection) in your Pojo setted to default values. In HQL you can get specified column values as follow:
Query query = session.createQuery("select u.fullname from Users u");
List<Object[]> rows = query.list();
List<String> fullnames = new ArrayList<String>();
for (Object[] row: rows) {
fullnames.add(row[0]);
}
I hope this will help you.
Tags contains tag with field name with value "#tylkoclara".
In first case results has size 1 which is expected result
SessionFactory sf = HibernateUtil.getSessionFactory();
Session session = sf.openSession();
session.beginTransaction();
List<Tag> results = new ArrayList<Tag>();
Criteria criteria = session.createCriteria(Tag.class);
criteria.add(Restrictions.eq("name", "#tylkoclara"));
results = criteria.list();I
But if I try to use whole collection as criteria, result's size is 0
public static List<Tag> filterTags(List<Tag> tags) {
SessionFactory sf = HibernateUtil.getSessionFactory();
Session session = sf.openSession();
session.beginTransaction();
Criteria criteria = session.createCriteria(Tag.class);
List<Tag> results = new ArrayList<Tag>();
for(Tag tag : tags) {
criteria.add(Restrictions.eq("name", tag.getName()));
}
results = criteria.list();
I have no ideas why is that happening
By adding your Restrictions in a loop like this, you are creating AND condition instead of OR condition. And since no tag has multiple different names, 0 results will be returned.
You need to create OR condition, for example like this (I've omitted the parts of your code dealing with session creation, etc to keep the example shorter):
public List<Tag> filterTags(List<Tag> tags) {
Criteria criteria = session.createCriteria(Tag.class);
Disjunction disjunction = Restrictions.disjunction();
for (Tag tag : tags) {
disjunction.add(Restrictions.eq("name", tag.getName()));
}
criteria.add(disjunction);
return criteria.list();
}
I understand some might simply answer this question with "Why didn't you just Google it"... But I did, and the more I researched this the more confused I got. I'm trying to query my database with Hibernate, the query has a 'where' clause.
Now creating a database entry is easy enough, in the case where I have a 'User' class, I simply do this:
// Gets a new session
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
// Creates a new User object
User user = new User("John", "p#55w0rd*", "john#doe.com");
// Save and commit
session.save(user);
session.getTransaction().commit();
But what do I do when I what to for instance
select * from Users where id = '3';
My Google searches pointed to something called HQL, which makes me wonder why I couldn't of just used straight JDBC then. Also it doesn't seem very object oriented. And then there's something like
session.createCriteria(.......
But I'm not sure how to use this.. Any help? Thanks guys.
When you use Native Query (non HQL ) you need to tell hibernate explicitely to handle it like below :
In below query createSQLQuery is special function to handle native sql's
String sql = "SELECT * FROM EMPLOYEE WHERE id = :employee_id";
SQLQuery query = session.createSQLQuery(sql);
query.addEntity(User.class);
query.setParameter("employee_id", 3);
List<User> results = query.list();
This can be done using criteria as well for that following is good starting point:
Criteria criteria = sess.createCriteria( User.class);
List<User> users= criteria.list();
http://www.developerhelpway.com/framework/hibernate/criteria/index.php
First of all, you need a hibernate.cfg.xml which contains properties for hibernate. This is e.g url, username and password, the driver and dialect. This file is placed in a package called resources.
You have to choose between using Hibernate Annotations example
or using hbm.xml files example
This is how you tell hibernate what your database is like. It wil automatically create queries for you based on how you annotates or defines in e.g user.hbm.xml.
Create a HibernateUtil.java class which holds the session factory.
You can fetch data from the database with
Criteria crit = getSessionFactory().getCurrentSession().createCriteria(User.class);
Example using queries:
List<?> hibTuppleResultList = currentSession.createQuery(
"from Person p, Employment e "
+ "where e.orgno like ? and p.ssn = e.ssn and p"
+ ".bankno = ?")
.setString(0, orgNo).setString(1, bankNo).list();
for (Object aHibTuppleResultList : hibTuppleResultList)
{
Object[] tuple = (Object[]) aHibTuppleResultList;
Person person = (Person) tuple[0];
hibList.add(person);
}
In the end all I really wanted was to know that if you don't want to use HQL you get something called 'Criteria Queries', and that in my case I'd do something like this:
Criteria cr = session.createCriteria(User);
cr.add(Restrictions.eq("id", 3));
List results = cr.list();
Me: "Thanks!"
Me: "No problem :)"
PS - we can really delete this question.
Query q = session.createQuery("from User as u where u.id = :u.id");
q.setString("id", "3");
List result = q.list();
Query with Criteria:
Criteria cr = session.createCriteria(User.class);
List results = cr.list();
Restrictions with Criteria:
Criteria cr = session.createCriteria(User.class);
cr.add(Restrictions.eq("id", 3));
// You can add as many as Restrictions as per your requirement
List results = cr.list();
You could also use it like this
List results = session.createCriteria(User.class).add(Restrictions.eq("id", 3)).list();
Some example for Crieteria Rsetriction query
Criteria cr = session.createCriteria(Employee.class);
// To get records having salary more than 2000
cr.add(Restrictions.gt("salary", 2000));
// To get records having salary less than 2000
cr.add(Restrictions.lt("salary", 2000));
// To get records having fistName starting with zara cr.add(Restrictions.like("firstName", "zara%"));
// Case sensitive form of the above restriction.
cr.add(Restrictions.ilike("firstName", "zara%"));
// To get records having salary in between 1000 and 2000
cr.add(Restrictions.between("salary", 1000, 2000));
// To check if the given property is null
cr.add(Restrictions.isNull("salary"));
// To check if the given property is not null
cr.add(Restrictions.isNotNull("salary"));
// To check if the given property is empty
cr.add(Restrictions.isEmpty("salary"));
// To check if the given property is not empty
cr.add(Restrictions.isNotEmpty("salary"));
You can create AND or OR conditions using LogicalExpression restrictions as follows:
Criteria cr = session.createCriteria(Employee.class);
Criterion salary = Restrictions.gt("salary", 2000);
Criterion name = Restrictions.ilike("firstNname","zara%");
// To get records matching with OR condistions
LogicalExpression orExp = Restrictions.or(salary, name);
cr.add( orExp );
// To get records matching with AND condistions
LogicalExpression andExp = Restrictions.and(salary, name);
cr.add( andExp );
List results = cr.list();
I think this will help you
I want to get distinct values from my db.
I have 10 fields in this db, and when i try to use such query:
SELECT DISTINCT (IMIE)FROM `przychodzace`
I get 26 results, but hibernate returns me just 17...
Here is list function:
List<String> list = new ArrayList<String>();
SessionFactory sf = HibernateUtil.getSessionFactory();
Session session = sf.openSession();
Criteria criteria = session.createCriteria(PrzychodzaceModel.class);
if (i == 0) {
criteria.setProjection(Projections.distinct(Projections.property("imie")));
criteria.addOrder(Order.asc("imie"));
}
list = criteria.list();
System.out.println(list.size() + "size");
return list;
Have anyone idea how to do it properly, i am trying to correct it for long time.
Thanks in advance.
I think an alternative to your problem would be to use a DAO class with a List method, eg:
public List listMenu() {
String hql = "FROM Menu";
org.hibernate.Query query = session.getCurrentSession().createQuery(hql);
query.setFirstResult(0);
query.setMaxResults(5);
List results = query.list();
return results;
}