Returns the value matching the key.
Since: Databricks Runtime 9.1
expr: Any expression of a comparable type.
keyN: An expression that matched the type of
valueN: An expression that shares a least common type with
defValueand the other
defValue: An optional expression that shares a least common type with
The result is of the least common type of the
The function returns the first
valueN for which
For this function NULL matches NULL.
defValue is returned if it exists.
defValue was specified the result is NULL.