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
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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.
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nullIf(delayReason, 'unknown')The following are the given field values.
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delayReason
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unknown
back ordered
weather delay For these field values, the following values are returned.
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(null)
back ordered
weather delay