The map_contains_key function may return true when the key and mapkeytype types are different.

scala>  val df = spark.sql("select map_contains_key(map(1, 'a', 2, 'b'), 2.0)")
val df: org.apache.spark.sql.DataFrame = [map_contains_key(map(1, a, 2, b), 2.0): boolean]

scala> df.show()
+--------------------------------------+
|map_contains_key(map(1, a, 2, b), 2.0)|
+--------------------------------------+
|                                  true|
+--------------------------------------+