Retrieving Plesk FTP Users Names and Passwords for Specific Domain

The following query will retrieve the sub-domain name, ftp username, and ftp password for a specific domain.

SELECT CONCAT(CONCAT(s.name, '.'), d.name) AS subdomain, u.login, a.password FROM subdomains AS s
JOIN domains AS d ON s.dom_id=d.id
JOIN sys_users AS u ON s.sys_user_id=u.id
JOIN accounts AS a ON u.account_id=a.id
WHERE d.name='example.com'

If you want to see all subdomains, then omit the WHERE clause.