备份.sql文件为空

Question

i am trying to backup mysql database by using this code

    include ("functions_cp/f_connection.php");

        Sqlconnection() ;



    $dbname = "Reservebox";
    $dbhost = "localhost";
    $dbuser = "root";
    $dbpass = "123";



$backupFile =  $dbname . date("Y-m-d-H-i-s") . '.sql';

$command = 'mysqldump -h' .  $dbhost . ' -u ' . $dbuser . '-p =' . $dbpass . ' '. $dbname . ' > ' . $backupFile ;
system($command);

the script works fine and it generates a .sql file , however this file is empty , how can i fix this problem ?

thanks

Answer 1

Don't put a space or equals sign between the -p and the password. Also, you are missing a space before the -p .

$command = 'mysqldump -h' .  $dbhost . ' -u ' . $dbuser . ' -p' . $dbpass . ' '. $dbname . ' > ' . $backupFile ;

Answer 2

Probably a file permissions error. Check that whatever user PHP and MySQL are running as have the permissions to write the file. FOr troubleshooting purposes, chmod the directory to 0777 and see if that fixes the problem. If so, chown the directory to whatever user MySQL is running as.