MySQL & PHP - Not unique table/alias

Question

I get the following error listed below and was wondering how do I fix this problem.

Not unique table/alias: \'grades\'

Here is the code I think

Answer 1

The problem seems to be here:

SELECT COUNT(*) 
FROM grades 
JOIN grades ON grades.id = articles_grades.grade_id
WHERE articles_grades.users_articles_id = '$page'"

You are trying to join the table grades to itself. You probably meant to join with articles_grades.