How to select multiple records from table in hibernate - mysql

Question

I am trying to get multiple values from a web page form and search the value from databate using hibernate query and retrieve the result and display it in a new page.
I need to get these text fields and even if any of the field is empty, I need to run a search query in database via controller and return set of results in a new page. I tried to store the result in array list of ArrayList but it didnt work. Could anyone please help me?
I am trying to get the text values from from web page in controller:
String lastname = request.getParameter("lastname");
String firstname = request.getParameter("firstname");
String gender = request.getParameter("gender");
String speciality = request.getParameter("speciality");
String keyword = request.getParameter("keyword");
I have Doctor's table which has all these texts fields stored. Lastname, firstname, gender, speciality. I have a class named doctor which links to the database.
#Entity
#Table(name="DOCTOR_DETAILS")
public class Doctor {
#Id
#Column (nullable=false)
private int npi;
#Column (nullable=false)
private String firstName;
#Column (nullable=false)
private String lastName;
#Column (nullable=false)
private String gender;
#Column (nullable=false)
private String speciality;
public int getNpi() {
return npi;
}
public void setNpi(int npi) {
this.npi = npi;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
public String getSpeciality() {
return speciality;
}
public void setSpeciality(String speciality) {
this.speciality = speciality;
}
}
I need to run a select query to retrieve the records from table. Even if any of the 4 fields are empty, the query should retrieve the records.
try {
begin();
ArrayList <String> cntList = new ArrayList<String>();
Query q = getSession().createQuery("select * from
doctor where lastName = :lastName or firstName =:firstName or
gender=:gender or speciality = :speciality");
q.setString("username", username);
cntList = (ArrayList<String>) q.list();
commit();
return cntList;
}
I tried the below way of using Hibernate criteria, but I am getting an error. Am I going wrong anywhere?.
I wrote below code in my controller:
Below part in my DAO class which connects to the database.
But I am getting below error:
Could you please help me out?
The code worked fine and returned the list of results. I tried to follow the steps provided in tutorial point site, but I am getting a cast error.
"Type mismatch: cannot convert from int to doctor.
A type mismatch asking me to change
Doctor doctor = iterator.next();
to
int doctor = iterator.next();
which is something weird, since I cannot retrieve values from Doctor class.

Answer 1

You should use Hibernate criteria query with disjunction. It's been designed to handle this sort of situations. Try this code snippet
public List<Doctor> getSearchResult(String firstName, String lastName, String gender, String speciality, Session session) {
Criteria cr = session.createCriteria(Doctor.class);
Disjunction or = Restrictions.disjunction();
if (firstName != null)
or.add(Restrictions.ilike("firstName", firstName+"%"));
if (lastName != null)
or.add(Restrictions.ilike("lastName", "%"+lastName));
if (gender != null)
or.add(Restrictions.eq("gender", gender));
if (speciality != null)
or.add(Restrictions.ilike("speciality", "%"+speciality+"%"));
cr.add(or);
return (List<Doctor>) cr.list();
}
You can get idea about Hibernate Criteria queries here.