Select only last value using group by at mysql

Question

I have one table with data about attendance into some events. I have in the table the data of the attendance everytime the user sends new attendance, the information is like

Answer 1

SUBSTRING_INDEX(SUBSTRING_INDEX(group_concat(%requiredfield%), ',', count(*)),',',-1)

This will get the last value of the 'required field' from any group_concat, if unsorted it will be the last value in the table by default.

Could use group_concat_ws to account for possible null fields.