Check out example codes for "oracle SQL developer". It will help you in understanding the concepts better.

Code Example 1

/* Answer to: "oracle SQL developer" */

/*
  Oracle SQL Developer is an Integrated development environment for
  working with SQL in Oracle databases. Oracle Corporation provides
  this product free; it uses the Java Development Kit.

  Download it here:
  https://www.oracle.com/tools/downloads/sqldev-downloads.html
*/

Learn ReactJs, React Native from akashmittal.com