User Quiz Attempts Records Deletion

How to delete user quiz attempts records?

1.) Go to 'LearnDash LMS' on left side bar menu -> 'Settings' -> 'Delete User Statistics and User Quiz Attempts'.

Only administrators has access on this page.

2.) You'll find a section at the bottom of the page with heading 'Delete User Quiz Attempts'.

3.) Process of deleting records involves 3 steps:

First Step: Filtering users who was registered to the site in between two dates. 

Second Step: Filtering user quiz attempts records in between two dates + users who registered in between dates filter.

Last Step: Deletion of the quiz attempts records.

After clicking 'Delete User Quiz Data' button, it would show a confirmation dialog box asking the user if they wanted to continue or not.

After clicking 'OK', the process of deletion will run and a progress bar with details of the deletion will show up.

Once all the records has been gone through, another dialog will show up showing how many records has been deleted successfully and failed. We show this up since sometimes the deletion fails because of too much records is being attempted to delete and it could cause error from the server. 

Recommended max number of users to lessen the chance of request error: 1000 or below.

What's the data being deleted?

This functionality delete array records on a multi-dimensional array stored on user meta with key '_sfwd-quizzes'.

Below is a sample record of the data. Each array records represents 1 exam attempts of a user on a specific exam.

Trello Card: https://trello.com/c/IokvSFlZ/363-fof-006-how-to-reduce-user-meta-table