Question

I’m working on an app in JavaScipt, jQuery, PHP & MySQL that consists of ~100 lessons. I am trying to think of an efficient way to store the status of each user’s progress through the lessons, without having to query the MySQL database too much.

Right now, I am thinking the easiest implementation is to create a table for each user, and then store each lesson’s status in that table. The only problem with that is if I add new lessons, I would have to update every user’s table.

The second implementation I considered would be to store each lesson as a table, and record the user ID for each user that completed that lesson there – but then generating a status report (what lessons a user completed, how well they did, etc.) would mean pulling data from 100 tables.

Is there an obvious solution I am missing? How would you store your users progress through 100 lessons, so it’s quick and simple to generate a status report showing their process.

Cheers!

Answer 1

The table structure I would recommend would be to keep a single table with non-unique fields userid and lessonid, as well as the relevant progress fields. When you want the progress of user x on lesson y, you would do this:

SELECT * FROM lessonProgress WHERE userid=x AND lessonid=y LIMIT 1;

You don’t need to worry about performance unless you see that it’s actually an issue. Having a table for each user or a table for each lesson are bad solutions because there aren’t meant to be a dynamic number of tables in a database.