WHERE Clause
The WHERE clause filters the rows coming from the FROM clause, returning the rows satisfying a given condition.
Syntax
where_clause ::= WHERE expression
Semantics
For each context row, the expression in the WHERE clause is evaluated. The result of this expression must have type BOOLEAN?. If the result is false, or empty, or NULL, the row is skipped; otherwise the row is passed on to the next clause.
Example 6-3 WHERE Clause
SELECT * FROM users WHERE firstname ="John";
The above example selects all information for users whose first name is "John".