Fatal error: Uncaught mysqli_sql_exception: Duplicate entry 'https://t.me/kimiagrup2k19' for key 'url' in /var/www/bootg/function.php:310 Stack trace: #0 /var/www/bootg/function.php(310): mysqli_query() #1 /var/www/bootg/add.php(93): insert() #2 {main} thrown in /var/www/bootg/function.php on line 310