Oracle Database 11g The Complete Reference

CHAPTER 13When One Query Depends upon Another

This chapter and Chapter 14 introduce concepts that are more difficult than we've previously seen. Although many of these concepts are rarely used in the normal course of running queries or producing reports, there will be occasions that call for the techniques taught in these chapters. If they seem too challenging as you study them, read on anyway. The odds are good that by the time you need these methods, you'll be able to use them.

Advanced Subqueries

You've encountered subqueries—those select statements that are part of a where clause in a preceding select statement—in earlier chapters. Subqueries also can be used in insert, update, and delete statements. This use will be covered in Chapter 15 ...