Null data functions

Null data functions handle or manipulate NULL values, which represent the absence of a value. The functions allow you to replace NULLs with other values, check if a value is NULL, or perform operations that handle NULLs in a specific way.

Function	Signature	Description
COALESCE	COALESCE (expression1, expression2, ..., expressionN)	If all expressions evaluate to null, COALESCE returns null. Expressions must be of same type.

Example of a COALESCE function

SELECT COALESCE (l.double_value, 100) AS non_double_value FROM latest_value_time_series AS l LIMIT 1