An expression is a combination of one or more values, operators, and SQL functions that evaluate to a value. You can use expressions in the Where and Having clauses of Select statements.

Expressions enable you to use mathematical operations as well as character string manipulation operators to form complex queries.

Valid expression elements are:

  • Constants
  • Numeric Operators
  • Character Operator
  • Relational Operators
  • Logical Operators
  • Functions