sql - Join tables in sqlite with many to many -

i have following database schema:

create table people (     id integer primary key autoincrement, );  create table groups (     id integer primary key autoincrement, ); 

and have people members of groups in separate file (let's in tuples of (person id, group id). how can structure database schema such it's easy access person's groups, , easy access members of group? difficult , slow read tuples have, want in database form. can't have things member1, member2, etc. columns because number of people in group unlimited.

move text file database table

create table groups_people (   groups_id integer,   people_id integer,   primary key(group_id, people_id) );   

and select people member of group 7

select * people p     left join groups_people gp on gp.people_id = p.id     gp.groups_id = '7'; 

and select groups person 5 in

select * groups g     left join groups_people gp on gp.groups_id = g.id     gp.people_id = '5';