Drop box sql schema

dropbox-db-schema.sql

CREATE TABLE user(
  user_id varchar(50) PRIMARY KEY,
  name varchar(50)
);

CREATE TABLE devices(
  device_id varchar(50) PRIMARY key,
  user_id varchar(50) not null,
  
  foreign key(user_id) references user(user_id)
);

CREATE TABLE objects(
  object_id varchar(50),
  device_id varchar(50),
  
  PRIMARY key(object_id, device_id),
  
  foreign key(device_id) references devices(device_id)
);

insert into user values('1', 'lol');

insert into devices values('1', '1');
insert into devices values('2', '1');
insert into devices values('3', '1');

insert into objects values('1', '1');
insert into objects values('3', '1');
insert into objects values('1', '2');

select device_id from objects where object_id='1';
select object_id from objects where device_id='1';