For this Tutorial, Oracle JDeveloper and Oracle database should be already installed. If these are not already installed, read my below blog for installation
Run the oracle JDeveloper and from file menu click at View -> Database -> Database Navigator as showing in snapshot below
For database new connection, Right click at IDE Connecter and select the New connection option
A Popup window will open for creation the database connection,
give the connection name for example Oracle_xe
Give the user name and password for your database like SYSTEM
Give the SID for your database. For Oracle Database XE, the default SID is XE. For same computer Host name will be localhost and if database is installed at any other computer then give the IP of that computer.
Click at Test button. If given information are OK then test result will success otherwise it will give error.
Click at OK to complete the connection setup
Now you can work with your database. If you have log in with administrator password you can create, delete, edit the database and users and much more.
To Edit and unblock the user follow the below as showing in snapshot. Double click the other users option to open the sub tree, now all added database users are listed.
For example to edit the HR user. Right click on it and click at edit user
A pop up window will open for database users creation and edit. Here you will find all options for users password creation / edition, Lock / unlock user, Roles etc.
Here in role type, you can assigned roles to users like admin role, DBA Role, creation, deletion, views etc.
In result tab, your all modification detail will be shown in SQL statements. By clicking at apply button, all modification will be applied to database with new roles,