Question

I am new to persistence world 🙂 May be my question is very silly and may be my approach is incorrect but that is what I want to ask some expert. So my problem is about writting a query for an entity that is related to another entity.

@Entity
public class Team {
  String teameName, 
  int teamId,

  @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
  @JoinColumn(name = "team_id", referencedColumnName = "teamId")
  private Set<Player> players;
  /**
     more code for getters and setter for all fields       
  */       
}

@Entity
public class Player {
    String PlayerName,
    String address 
    /**
     *more code for getters and setter for everything       
    */
}

So multiple player can belong to one team but every player must have a unique Team which is done with making teamId as a foreign key to Player.
As far as I can think this should be correct.But now comes the problem.
Now I want to make a query to find all the players with “playerName=X” and “teamId =Y”
And I have no idea how to write such query.

Please can anyone suggest me something.

Thanks in advance.

Jeena

Answer 1

You want to read about HQL, the Hibernate Query Language. It’s kind of like SQL.

Basically you define you hql string, and then execute the query. Something like

String hql = "select * from Player p where p.PlayerName = :name and team = :team";
Query query = session.createQuery(hql);
query.setParameter("name", "Joe");
query.setParameter("team", team);
List list = query.list();