It is impossible to log in to database by using Plesk admin password literally:
# mysql -uadmin -p"admin_plain_password" psa ERROR 1045 (28000): Access denied for user 'admin'@'localhost' (using password: YES)
cat works with no issues:
#mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa mysql>
How to login to database by setting admin password literally?
Plesk admin's password is stored in
/etc/psa/.psa.shadow in encrypted state for secure reason.
To use admin's password without using
cat use the encrypted string from the file
/etc/psa/.psa.shadow but make sure to screen the system symbols with "\":
# mysql -uadmin -p"\$AES-128-CBC\$==\$tfwf7sqps2DHllv03wmY9A==" psa mysql>
NOTE: To set or retrieve Plesk admin password use KB #346