Notice: Undefined variable: db in
/var/www/html/webteach.tw/tools/computer/product_computer.php on line
169Fatal error: Uncaught Error: Call to a member function query() on null in /var/www/html/webteach.tw/tools/computer/product_computer.php:169
Stack trace:
#0 {main}
thrown in
/var/www/html/webteach.tw/tools/computer/product_computer.php on line
169