Purpose

Specifies the conditions that rows must meet to be retrieved.

Syntax

WHERE expr1 rel_operator expr2

where:

expr1
is either a column name, literal, or expression.
expr2
is either a column name, literal, expression, or subquery. Subqueries must be enclosed in parentheses.
rel_operator
is the relational operator that links the two expressions.

Example

The following Select statement retrieves the first and last names of employees that make at least $20,000.

SELECT last_name, first_name FROM emp WHERE salary >= 20000