title: I have installed Oracle Developer Day on OS X. Why is there a need to add new connection?
body: <p>So, I'm trying to learn SQL. I started the labs(in Developer Day) which asked me to add a new connection. My question, to be specific, is Why to make a new connection when you already have a 'System' connection, with 'oracle' as password. </p>
  
  <p>And, is there any 'bible' for SQL where dummies like me can start from scratch and learn SQL from Basics to pro level?</p>