java - JPA: Retrieve a list from secondary table using a composite key -

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well, here have example of i'm trying no success. sorry dummy example. have following tables:

create table house(   house_name varchar2(255),   owner_id varchar2(255),   primary key(folder_name, user_id) );  create table pet(   house_name varchar2(255) not null,    owner_id varchar2(255) not null,   pet_name varchar2(255) not null );  alter table pet   add constraint fk_pet_house     foreign key(house_name, owner_id)     references house(house_name, owner_id)     on delete cascade;  insert house values('house 1', 'owner 1'); insert house values('house 2', 'owner 1'); insert house values('house 3', 'owner 1');  insert pet values('house 1', 'owner 1', 'dog'); insert pet values('house 1', 'owner 1', 'cat'); insert pet values('house 2', 'owner 1', 'duck'); insert pet values('house 3', 'owner 1', 'bird');

as can see i'm using composite key in "house" table. want db 3 objects this:

owner id: owner1 house name: house 1 pets: [dog, cat]  owner id: owner1 house name: house 2 pets: [duck]  owner id: owner1 house name: house 3 pets: [bird]

i've been searching way don't know how link these tables retrieve list. have far is:

@entity @table(name="house") @secondarytable(name="pet", pkjoincolumns={         @primarykeyjoincolumn(name="house_name", referencedcolumnname="house_name"),         @primarykeyjoincolumn(name="owner_id", referencedcolumnname="owner_id"), }) public class housepets implements serializable {      @id     @column(name="house_name")     private string housename;      @id     @column(name="owner_id")     private string ownerid;      @column(table="pet" name="pet_name") //don't know how deal     private set<string> petsset = new hashset<string>      //getters , setters }

and retrieve list i'm using method this:

    public list<housepets> getfolderslist() {         em = emf.createentitymanager();         query q = em.createquery("select h housepets h h.ownerid = :ownerid");         q.setparameter("ownerid", "owner 1");         list<housepets> result = q.getresultlist();         return result;     }

thanks time!

your model makes no sense. secondarytable cannot onetomany relation.

what need owner table, defines owner_id, (maybe name, etc.)

owner have onetomany pet, , onetoone (or manytoone, onetomany?) house

pet have manytoone owner , manytoone house

house have onetomany pet , onetomany? owner

to own, select owner, pets access them.


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