A. Pre Upgrade
1. Download SQL Developer & Extract
2. To connect to third-party database (MySQL, Microsoft SQL Server, Sybase Adaptive Server, Microsoft Access, IBM DB2) using SQL Developer, we need jTDS driver. You can download needed jTDS driver from following link. http://sourceforge.net/projects/jtds/files/jtds/1.2/jtds-1.2-dist.zip/download .
Extract the dowloaded zip file named jtds-1.2-dist.zip
3. Click “Tools” and then “Prefenrences”.