Fatal error: Uncaught Error: Call to undefined function mysql_query() in D:\phpstudy_pro\WWW\qc4sd\4S2018\e\class\connect.php:152 Stack trace: #0 D:\phpstudy_pro\WWW\qc4sd\4S2018\e\class\connect.php(120): do_dbconnect('localhost', '', 'qc4sd', 'MRHNqc4sd#2017', 'db_qc4sd2018') #1 D:\phpstudy_pro\WWW\qc4sd\4S2018\e\public\onclick\index.php(10): db_connect() #2 {main} thrown in D:\phpstudy_pro\WWW\qc4sd\4S2018\e\class\connect.php on line 152