I've crammed all I can manage about SQL into this one chapter. Yet SQL is a complex topic, and all I've done is to introduce you to the basic operations. If you work with Oracle ”in fact, if you work with any database ”you owe it to yourself to thoroughly master the use of SQL. To that end, I heartily recommend the following books, all published by O'Reilly:
Mastering Oracle SQL, Second Edition
By Sanjay Mishra and Alan Beaulieu, this book begins where this chapter ends and plumbs the depths of what you can accomplish using Oracle's implementation of SQL. If you read only one book from this list, make it this one.
A book by Dan Tow that teaches his unique method of diagramming SQL queries as a precursor to resolving SQL performance problems. Not only do his query diagrams help you identify the optimal or near-optimal execution plan for a query, they can also point out hidden problems in complex query logic.
SQL Pocket Guide
A small book I wrote that can serve as a handy, portable, pocket- sized reminder of basic SQL syntax and functionality.
Oracle SQL*Plus: The Definitive Guide (Definitive Guides)
Authors: Jonathan Gennick
Simiral book on Amazon