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Fatal error: Uncaught TypeError: mysqli_real_escape_string(): Argument #1 ($mysql) must be of type mysqli, null given in C:\Users\Administrator\OneDrive\AlexCD Backup\Dokumente\Trabajo\Web Developer\LibreriaACD\SQL\Datos Query.php:7 Stack trace: #0 C:\Users\Administrator\OneDrive\AlexCD Backup\Dokumente\Trabajo\Web Developer\LibreriaACD\SQL\Datos Query.php(7): mysqli_real_escape_string(NULL, 6) #1 {main} thrown in C:\Users\Administrator\OneDrive\AlexCD Backup\Dokumente\Trabajo\Web Developer\LibreriaACD\SQL\Datos Query.php on line 7