DataSource Creation in websphere

Go to JDBC provider-> New

You can select the database you want to use like Oracle,DB2 etc..

I had used Oracle for example.

In next step it will  ask for the path of ojdbc jar which is needed for oracle jdbc connections.Use the latest jars compatible with your database version.

Click on Finish and save to master config to complete jdbc provider creation.

Click on datasource ->new

I used the cell scope so it will be visible to all applications.

Enter the datasource name and jndi name

The database URL for Oracle will be in the format :
jdbc:oracle:thin:@[ip address]:[Oracle port (1521)]:[Oracle database name]
ex:jdbc:oracle:thin:@localhost:1521:testdb

DataSource Creation is completed.
The next step will be to configure J2C authentication

Click on JAAS-J2C authentication 

Enter username and password for the database schema connectivity

Last step to test the connection

Click on TestConnection. 
Other Useful links for datasource creation:
Datasource creation explained for oracle,mqsql