The IF and CASE functions are the most basic and widely used SQL functions for conditional logic. They let you return different values or expressions based on a condition or a series of conditions.

constant is a number or a quoted character string (or other special notation) that indicates a fixed value. Constants are also called literals. query-expression is described in query-expression.

ZetaSQL supports conditional expressions. Conditional expressions impose constraints on the evaluation order of their inputs. In essence, they are evaluated left to right, with short-circuiting, and ...