Window--->perspective--> open perspective-->others--.>Database Development

Data Source Explorer-->Right click on Database Connections-->New

Connection Profile window will pop up

Select Database (Oracle/Derby/...)

You can give any name to your database.

Click Next

Specify a Driver and Connection Details window will pop up

Select the Driver by clicking on plus icon

Specify a Driver template and Definition Name window will pop up

Select your driver (For example: JDBC Embedded Driver)

Go to JARList tab

Remove existing jar file(s) (if any) and add the jar file present in your system. Click OK

Click test connection 

if ping is successfull, click Finish.