Hibernate Restriction Is Null function
In this section, you will learn about Hibernate restriction isNull() or Restrictions.isNull() function with running example, code and its output. Here, we will see the hibernate restriction isNull () method description with running example.
isNull(): Hibernate isNull() method is used with hibernate Restrictions. The hibernate Restrictions.isNull() function gives you all values which having null value for given property(table's column).
Restrictions.isNull("field_name"): Hibernate Restrictions.isNull() function takes a parameter as a property name or table's column name. It gives you all result which having null value of given column as a property.
Now, We will see the running example of Restrictions.isNull() or isNull() function. The following example match the field_name = "empExpences". Which having null value in empExpences coluemn.
package developerhelpway.hibernate.criteria.restriction;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.criterion.Restrictions;
import developerhelpway.hibernate.Employee;
public class RestrictionIsNullExample {
/**
* @param args
*/
public static void main(String[] args) {
Session sess = null;
try{
SessionFactory sf = new Configuration().
configure().buildSessionFactory();
sess = sf.openSession();
Transaction tr = sess.beginTransaction();
Criteria criteria = sess.createCriteria(
Employee.class);
criteria.add(Restrictions.isNull("empExpences"));
List<Employee> employees = criteria.list();
System.out.println("Get Employee
which having with null expences:");
for(Employee emp: employees){
System.out.println(
"Id: " + emp.getEmpId()
+ ", EmpName: " + emp.getEmpName()
);
}
tr.commit();
}catch(Exception ex){
ex.printStackTrace();
}finally{
if(sess != null){
sess.close();
}
}
}
}
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Download Restriction IsNull function Example
After running this example you will see the following output and SQL query which is generated by hibernate:
Hibernate: select this_.emp_id as emp1_0_0_, this_.emp_name as emp2_0_0_, this_.emp_sal as emp3_0_0_, this_.emp_expences as emp4_0_0_ from employee this_ where this_.emp_expences is null
OutPut:
