PHP会话相关问题

Is session necessary for user login checking or it can be done alternatively by checking the username with database matching?? If it is done by database checking with the username or email then what is necessecity of Session? please tell me with explanation if possible..thank you

Session is a type of cookie that used for tracking user after login! for example: after user submitted username and password, and you did matched against database, then, you probably don't want to authenticate again (re checking username and password for every page hit), therefore, you can save an identifier in session for recognizing user that successfully logged-in.

Usually, seesion will be expired once user closed the windows, while, cookie can be kept for long time.

Basic Logic:

1. Check if username and password submitted
2. Check if submitted username and password exists in the database
3. If second condition true, then create session

No, session is not necessary for user checking.Session is for keeping track of a user as he moves on your website.As the user navigates your pages session keeps track of him.For example,a user on this site,has all its data "with him" no matter what page he`s on.