To View Database via PhpMyAdmin / ASP.Net Enterprise Manager in Plesk, Please follow the following steps :-
1) Login to Plesk control panel.
2) Click on "Websites & Domains".
3) Click on "Databases".
4) Click on "Webadmin" against the particular Database.
If the database is Mysql then you will get screen phpMyAdmin Screen.
If the database is MSSQL then you will get screen ASP.NET Manager Screen.