Conditional

This section describes the following conditional functions:

Function	Description
COALESCE	Returns the first input that is not null. If an input is an array, the whole array is returned. Empty arrays are not selected and are considered to be equivalent to a null value.
IF_ELSE	If there is a true Boolean value in the condition parameter, then return the second argument. In all other cases, return the third argument
NULL_IF	If there is a true Boolean value in the condition parameter, then return null. Otherwise, return the second argument