nullIf compares two expressions. If they are equal, the function
returns null. If they are not equal, the function returns the first
expression.
Syntax
nullIf(expression1,expression2)
Arguments
nullIf takes two expressions as arguments.
- expression
-
The expression can be numeric, datetime, or string. It can be a field name, a literal value, or another function.
Return type
String
Example
The following example returns nulls if the reason for a shipment delay is unknown.
nullIf(delayReason, 'unknown')The following are the given field values.
delayReason
============
unknown
back ordered
weather delay For these field values, the following values are returned.
(null)
back ordered
weather delay