MAP_CONTAINS_KEY

Description

Determines whether the given map contains a specific key key

Syntax

MAP_CONTAINS_KEY(<map>, <key>)

Parameters

Parameter	Description
<map>	Input map content
<key>	The key to be retrieved

Return Value

Determines whether the given map contains a specific key key, and returns 1 if it exists, otherwise returns 0.

Example

select map_contains_key(map(null, 1, 2, null), null),map_contains_key(map(1, "100", 0.1, 2), 0.11);

+-----------------------------------------------+-----------------------------------------------+
| map_contains_key(map(null, 1, 2, null), null) | map_contains_key(map(1, "100", 0.1, 2), 0.11) |
+-----------------------------------------------+-----------------------------------------------+
|                                             1 |                                             0 |
+-----------------------------------------------+-----------------------------------------------+

• Key comparison in maps uses "null-safe equal" (null and null are considered equal), which differs from the standard SQL definition.

select map_contains_key(map(null,1), null);

+-------------------------------------+
| map_contains_key(map(null,1), null) |
+-------------------------------------+
|                                   1 |
+-------------------------------------+