SQL Server : Connections in SQL Developer
Download the latest "jTDS - SQL Server and Sybase JDBC driver" from here.
Unzip the driver, giving you a "jtds-1.3.1.jar" file.
Open SQL Developer and navigate to "Tools > Preferences > Database > Third Party JDBC Driver".
Click the "Add Entry..." button and highlight the "jtds-1.3.1.jar" file and click the "Select" button.
Click the "OK" button to exit the "Preferences" dialog.
When you create a new connection, you will notice "SQLServer" and "Sybase" tabs have now appeared. Enter the connection details and test the connection.
For more information see:
Hope this helps. Regards Tim...