nullIf
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