can temporary tables be used in PHP?

If you want response in a small period of time you should hire someone with the knowledge on how to fix the issues....
It's a forum were people help each other, not a free helpdesk to solve your issue in a small period of time.

Now for the question:
Do you have an example of the code you are running now inside CI3?

Also for debugging (hint: at the end of the page): https://codeigniter.com/userguide3/datab...eries.html