https://hotexamples.com/examples/-/-/resize_image/php-resize_image-function-examples.html
https://ourcodeworld.com/articles/read/197/how-to-resize-an-image-and-reduce-quality-in-php-without-imagick
https://www.sitepoint.com/community/t/problem-generating-thumbnail-from-imagejpeg/94340
https://www.php.net/manual/en/function.imagejpeg.php

mysql case

https://www.plus2net.com/sql_tutorial/sql_case.php