导出的数据库为空

I have a code to backup my database by using mysqldump. However, the output is a file with blank data inside. Below is the script.

$command = "mysqldump -u root -p vti_ctes_demo > db/backupfile.sql";
system($command);

mysqldump -u root -p[root_password] [database_name] > dumpfilename.sql

it looks like you forgetting to type the password

Remove the space between -p and the password.

$command = "mysqldump -u root -pvti_ctes_demo > db/backupfile.sql";