- id
- title
- slug
- body
- count
- related <->
- difficulty <->
- timestamp
- author
- answer
- test_cases
- succesful ->
- id
- password
- usarname
- time_registered
- bio
- avatar
- active
- roles ->
- wish_list ->
- submissions ?->
- id
- user ->
- problem ->
- time
- datestamp
- error_type
- error_case