How to massively change string capitalization in a table?
Mysql has a mechanism called cursors that allows to read all the rows from the table one by one. Detailed description can be found here:
https://dev.mysql.com/doc/refman/8.0/en/cursors.html
You have to write a stored routine with a cursor loop inside and to place some case transforming logic in it. Useful functions are LOWER(), UPPER(), SUBSTRING() and other text functions described here:
https://dev.mysql.com/doc/refman/8.0/en/string-functions.html