3
Operators

With affection beaming in one eye, and calculation shining out of the other.

Charles Dickens, Martin Chuzzlewit

An operator manipulates individual data items and returns a result. The data items are called operands or arguments. Operators are represented by special characters or by keywords. For example, the multiplication operator is represented by an asterisk (*) and the operator that tests for nulls is represented by the keywords IS NULL.

This chapter discusses the following topics:

• Unary and Binary Operators

• Precedence

• Arithmetic Operators

• Concatenation Operator

• Comparison Operators

• Logical Operators

• Set Operators

• Other Built-In Operators

• User-Defined Operators