How secure is authorization?

Question

PHP

How authorization works:

Table users: login, password, cookie

Пользователь переходит на страницу логина-> вводит данные, я проверяю, есть ли они в базе-> if found, I take a cookie (a random string from the database) and save it to the browser.

On each page of the site, I check the user's key to see if it is in the database.

I don't use session from php, just a cookie. How correct is this option in general, and from a security point of view?

upd: the question is in fact, the answers are also asking in fact, please.

Answer 1

Better fasten oauth2
Especially since the entrance through the social. networks are now practically standard.