It is possible that the database server is not running on your server
It often happens because ISPManager itself starts before the mentioned services, scans the contents and hides them in order not to confuse the user with nonfunctional (the MySQL service is not running yet) links.
To start it, go to "Server settings → Features ", make sure that the database server is on (yellow light):
if not enabled, highlight the database server and click On in the upper right corner.
Similarly, make sure that the MySQL service is running by going to "Tools → Services ":
if not enabled, highlight the service and click Start in the upper left corner.
If starting the database server from the control panel fails, connect to the server via "SSH " and run the command:
service mysqld start
For Debian, Ubuntu:
service mysql start
Second way: if you cannot log into phpmyadmin as root and error #1045 Cannot connect to MySQL server is popping up
Reset the mysql user root password.
Start mysql via command:
/usr/bin/mysqld_safe --skip-grant-tables --user=root &
& indicates that the command will run in the background.
Running mysql from root:
mysql -u root
Change password, update mysql user privileges and logout:
mysql> update mysql.user set Password=PASSWORD('new password') WHERE User='root'; mysql> flush privileges; mysql> exit
mysql -u root -p