erDiagram
Car {
int id PK
string model
timestamp registered_at
int user_cars FK
}
Group {
int id PK
string name
}
group_users {
int group_id PK,FK
int user_id PK,FK
}
User {
int id PK
int age
string name
timestamp time
jsonb json
}
Group |o--o{ group_users : users-groups
User |o--o{ Car : cars-owner
User |o--o{ group_users : groups-users