Informix Guide to SQL: Tutorial Composing Advanced SELECT Statements

In This Chapter

Using the GROUP BY and HAVING Clauses

Using the GROUP BY Clause

Using the HAVING Clause

Creating Advanced Joins

Self-Joins

Outer Joins

Simple Join

Simple Outer Join on Two Tables

Outer Join for a Simple Join to a Third Table

Outer Join of Two Tables to a Third Table

Joins That Combine Outer Joins

Subqueries in SELECT Statements

Subqueries in a Select List

Subqueries in WHERE Clauses

Using ALL

Using ANY

Single-Valued Subqueries

Correlated Subqueries

Using EXISTS

Handling Collections in SELECT Statements

Collection Subqueries

Omitting the Item Keyword in a Collection Subquery

Specifying the ITEM Keyword in a Collection Subquery

Collection-Derived Tables

Set Operations

Union

Difference

Summary