java - Android Room Persistence Library : What is the best way to implement a many to many relation? -

i used use realm , testing room in order compare both tools.

i trying implement following many many relation :

here entity classes :

the person :

@entity(tablename = "person") public final class roomperson {    @primarykey   public int id;    public string name;  } 

the cat class :

@entity(tablename = "cat") public final class roomcat {    @primarykey   public int id;    public int age;    public string name;  } 

and personcat class :

@entity(tablename = "person_cat", primarykeys = { "personid", "catid" },     indices = { @index(value = { "catid" }) },     foreignkeys = { @foreignkey(entity = roomperson.class, parentcolumns = "id", childcolumns = "personid"),         @foreignkey(entity = roomcat.class, parentcolumns = "id", childcolumns = "catid") }) public final class roompersoncat {    public int personid;    public int catid;    public roompersoncat(int personid, int catid)  {     this.personid = personid;     this.catid = catid;   }  } 

i have pojo in order manipulate person cats app :

public final class roompersonwithanimals {    @embedded   public roomperson person;    @relation(parentcolumn = "id", entitycolumn = "id", entity = roomcat.class)   public list<roomcat> cats;  } 

the question : how save list<roompersonwithanimals> ?

should 3 requests each time in order save :

• the person table person
• the cats table cat
• its cats table personcat

here java code illustrate 3 requests :

for (roompersonwithanimals personwithanimals : persons) {   myroomdatabase.roompersondao().insert(personwithanimals.person);   myroomdatabase.roomcatdao().insertall(personwithanimals.cats.toarray(new roomcat[personwithanimals.cats.size()]));    (roomcat cat : personwithanimals.cats) {     myroomdatabase.roompersoncatdao().insert(new roompersoncat(personwithanimals.person.id, cat.id));   } } 

in realm, it's possible save in 1 request these data. is limitation of room or implementation wrong ?

thank in advance !