Hibernate Sqlquery - Get Object by Name
I Have a Method to Get a Category by Its "Id" and I Need a Similar Method to Get a Category by Its "Name". I Did These Methods by Using Hibernate. How Can I...
I have a method to get a Category by its "id" and I need a similar method to get a Category by its "name". I did these methods by using Hibernate. How can I fix my second method to get a Category by name? My source code is as follow:
// It works
@Override
public Category getById(int id) {
return (Category) sessionFactory.getCurrentSession().get(Category.class, id);
}
// It doesn't works
@Override
public Category getByName(String name) {
return (Category) sessionFactory.getCurrentSession().
createSQLQuery("SELECT FROM Category WHERE name="+name);
}
I have this error with the second method:
java.lang.ClassCastException: org.hibernate.impl.SQLQueryImpl cannot be cast to com.sedae.model.Category
These are my controllers.
@RequestMapping(value = "/getCategoryById/{id}")
public String getCategoryById(Model model, @PathVariable ("id") int id){
model.addAttribute("category", categoryService.getById(id));
return "/getCategoryById";
}
@RequestMapping(value = "/getCategoryByName/{name}")
public String getCategoryByName(Model model, @PathVariable("name") String name){
model.addAttribute("category", categoryService.getByName(name));
return "/getCategoryByName";
}
Thanks in advance people.
1 Answer
If you are sure you have only one entry per category name in your table then you can use Query#uniqueResult:
Query query= sessionFactory.getCurrentSession().
createQuery("from Category where name=:name");
query.setParameter("name", name);
Category category = (Category) query.uniqueResult();
Make sure to handle the exceptions thrown by uniqueResult.
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