Student's registration

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Fatal error: Uncaught mysqli_sql_exception: php_network_getaddresses: getaddrinfo for babeltest failed: H�te inconnu. in D:\wwwroot\opticon\la_caille\etudiant\inscription.php:156 Stack trace: #0 D:\wwwroot\opticon\la_caille\etudiant\inscription.php(156): mysqli_connect() #1 {main} thrown in D:\wwwroot\opticon\la_caille\etudiant\inscription.php on line 156