database structure question, for multiple questions ramdomaly called.

Question

I want to create a website for training multiple choice questions, the problem is that i don't want to repeat the question for each user, i will have many questions and the probability that random gets the same question is very small, and its important for me that user doesn't see the same question, so is it so pad demand to do this? and how could i do this.. i thought to save a list of all questions id, and use it to call new questions haven't been used and save the change....this way i have to save a string that loads on login, containing all questions, is this an efficient way to do it??

any ideas are welcomed to change the structure for better

Answer 1

I think your base idea is correct. Store the ID's of the question a user already answered somewhere. Similar to

      asked_questions
--------------------------
user_id           int
question_id       int

With this, you can easily do

SELECT * FROM questions WHERE questions.id NOT IN (SELET asked_questions.question_id FROM asked_questions WHERE asled_questions.user_id = currentLoggedInUserId) LIMIT 10;

and have 10 questions the user has not seen yet.