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Warning: include(): Failed opening 'includes/head.php' for inclusion (include_path='C:\xampp\php\PEAR') in C:\xampp\htdocs\strasidelny_priklad_2.php on line 7

Notice: Undefined variable: mysqli in C:\xampp\htdocs\strasidelny_priklad_2.php on line 38

Fatal error: Uncaught Error: Call to a member function query() on null in C:\xampp\htdocs\strasidelny_priklad_2.php:38 Stack trace: #0 {main} thrown in C:\xampp\htdocs\strasidelny_priklad_2.php on line 38