Hi,

I am trying to save a new department in database using merge, however nothing gets saved in database. It doesn't even give any error/exception.

Following is the snapshot of my code:

Controller Method:    

   @RequestMapping(value="/department/add.html", method = RequestMethod.POST)
    public String edit( @ModelAttribute Department department )
    {
        department = deptDao.saveDepartment(department);
        return "redirect:/department/list.html";
    }

Dao Method:

    @Override
    @Transactional
    public Department saveDepartment(Department department) {
        return entityManager.merge(department);
    }

I am no sure why this happens, can someone please help?

Note:

I have used @Transactional in the Dao method and everything else as explained by prof. Sun in the class. But still nothing gets saved in database.

Well I am not sure about that, but eclipse shows that entityManager.save doesn't exists.

Also, in the class, prof Sun had explained that entityManager.merge can handle both add/edit operations based on primary key.

So If a key exists already, then it updates it else adds it.

I have checked that applicationContext.xml has <tx:annotation-driven /> there.

Also, doing System.out.println(department.getName()) prints the name I entered in the form. So it means that the method saveDepartment() is getting called with correct arguments.

My model class looks like this,

@Entity
@Table(name = "departments")
public class Department implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    @Column(name = "dept_id")
    int id;
    @Column(name = "dept_name")
    String name;

    @ManyToMany
    private List<Users> users;

}

And form looks like this:

                              <form:form modelAttribute="department">
                  <div class="form-group">
                    <label>Department Title</label>
                    <form:input path="name" class="form-control" />
                  </div>

                  <button type="submit" class="btn btn-primary">Save</button>

               </form:form>

Is everything correct in there? Really appreciate your help.

That's unfortunate, I'm actually have the exact same problem (and have likewise followed similar debugging steps).  The only (and perhaps major) difference is that merge is performing a update instead of a insert operation in the database.  How do you approach debugging in Hibernate?   

Also, if this issue isn't resolved have you tried checking what Hibernate is auto generating as the PK for the new entry?

(This was my issue: create sequence hibernate_sequence minvalue 2000000;  Also, I think this is horrible)