- useri aplikacije su definirani emailom koji je unique kolumna - ne zelimo vise usera sa istim emailom
create table users(id integer primary key, email varchar(40) not null);
create unique index email on users(email);
Column | Type | Collation | Nullable | Default
--------+-----------------------+-----------+----------+---------
id | integer | | not null |
email | character varying(40) | | not null |