Database architecture

Database architecture

users

name	type
id	integer auto-incremental primary key
username	text field up to 32 symbols, can not be empty
password	text field up to 32 symbols, can not be empty
first_name	text field up to 32 symbols, can not be empty
last_name	text field up to 32 symbols, can not be empty
sh_key	text field up to 618 symbols, can not be empty
registration_time	text field in format HH:MM:SS_DD-MM-YY, can not be empty

pictures

name	type
id	integer auto-incremental primary key
from_user_id	integer foreign key, references table users, can not be empty
to_user_id	integer foreign key, references table users, can not be empty
had_been_read	boolean value, can not be empty, default - 0
info_from_user	text field up to 255 symbols

contacts

name	type
1_user_id	integer foreign key, references table users, can not be empty
2_user_id	integer foreign key, references table users, can not be empty
Combination of 1_user_id and 2_user_id can be used as primary key for this table.

sessions

name	type
id	integer auto-incremental primary key
user_id	integer foreign key, references table users, can not be empty
start_time	text field in format HH:MM:SS_DD-MM-YY, can not be empty
finish_time	text field in format HH:MM:SS_DD-MM-YY, can not be empty
number_of_encoded_pictures	integer, can not be empty
number_of_decoded_pictures	iinteger, can not be empty