9 SQL Queries and Subqueries

This chapter describes SQL queries and subqueries.

This chapter contains these sections:

• About Queries and Subqueries

• Creating Simple Queries

• Hierarchical Queries

• The UNION [ALL], INTERSECT, MINUS Operators

• Sorting Query Results

• Joins

• Using Subqueries

• Unnesting of Nested Subqueries

• Selecting from the DUAL Table

• Distributed Queries