User with uid=0 in database

Question

I had to build a form with a select field populated with all the users registered in database. There are 10 users that I can see in admin>people.

To get all the users, I used entity_load('user').

But in my select, I have one empty option in addition to my 10 users.

I checked in my database, and I found this empty UID=0 record:

I searched the Internet but I didn't find a satisfying answer. I read something about Anonymous user but I didn't get it.

• Is this record important?
• Does it have to be there?
• If yes, I'll do some trick to ignore it in my select.
• If not, can I just delete it?

Thank you in advance for this little trivial question.

Answer 1

Is this record important?

Yes, it prevents some queries from failing if it's anonymous user who caused them.

Does it have to be there?

There is a possibility site would stay browsable you remove it... but it would mess your login functionality and may prevent sessions from persisting.

If yes, I'll do some trick to ignore it in my select.

Consider using EntityFieldQuery. Omit UIDs lower than 1, or select only users with name, etc.