JPQL select based on OneToMany field

Question

I have these entities:
This is a person
@Entity
@Table(name = "Person", schema = SCHEMA)
public class Person{
//TODO: select unique field. Now sourceUrl plays role of unique field.
     @Id
     @GeneratedValue
     private int id;
     @OneToMany(fetch=FetchType.EAGER, cascade={CascadeType.ALL}, mappedBy="person")
     private List<PoliticalPartyMembership> politicalPartyMemberships;
//other fields, getters and setters
}Person can have several PoliticalPartyMemberships (some kind of his political history)
@Entity
@Table(name = "PoliticalPartyMembership", schema = SCHEMA)
@IdClass(PoliticalPartyMembership.PK.class)
public class PoliticalPartyMembership {
     @Id
        @ManyToOne(fetch=FetchType.EAGER, cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
     private Person person;
     @Id
     @ManyToOne(fetch=FetchType.EAGER, cascade={CascadeType.MERGE, CascadeType.REFRESH, CascadeType.PERSIST})
     private PoliticalParty politicalParty;
     @Id
     private Date dateIn;
     private Date dateOut;
     public static final class PK implements Serializable {
          public int person;
          public String politicalParty;
          public Date dateIn;
          @Override
          public boolean equals(Object o) {
               if (!(o instanceof PK))
                    return false;
               PK oPK = (PK)o;
               return this.politicalParty.equals(oPK.politicalParty)  && this.person == oPK.person && this.dateIn.equals(oPK.dateIn);
          @Override
          public int hashCode() {
               return ((person == 0) ? 0 : new Integer(person).hashCode())
               ^ ((politicalParty == null) ? 0 : politicalParty.hashCode())
               ^ ((dateIn == null) ? 0 : dateIn.hashCode());
//other fields, getters and setters
}And finally PoliticalParty entity
@Entity
@Table(name = "PoliticalParty", schema = SCHEMA)
public class PoliticalParty {
     @Id
     private String fullName;
     private String abbreviation;
     private String shortName;
//other fieldssetters and getters
}I have to make a query with these parameters:
1. PoliticalParty name
2. date period (dateIn and dateOut of politicalPartyMembership)
I want to retrieve all persons which were in specified PoliticalParty (by name) in the specified period (dateIn dateOut)
How can I do that using query, I don't understand. Is it possible?
I have only two Ideas:
1. Very stupid: get all (oh my god) Persons and examine their field named PoliticalPartyMembership. It's easy, stupid and slow
2. Not very stupid: select all PoliticalPartyMemebership with query like
Query q = em.createQuery("select ppm from PoliticalPartyMembership ppm where ppm.dateIn=: dateIn and dateOut=: date out and ppm.politicalParty.fullName=:fullname");Then, I'll get all PoliticalPartyMemeberships and field Person will help me to retrieve persons I need.
Are there any other solutions?

Answer 1

Hi Steve,
You cannot sort on a formula field that uses printime functions or executes in the 'whileprintingrecords' phase - example would be running totals or formulae based on shared variables from the subreport.
What you can however do is, suppress records where the formula returns zero.
To do this, go to the Section Expert > Select the section you wish to suppress > Click the formula button beside 'Suppress' and use this code"
{@Formula_name} = 0
-Abhilash