MAP_CONTAINS_KEY

Description

The MAP_CONTAINS_KEY function is used to determine whether a given map type data contains an entry that matches the specified key. When the specified key exists in the map, the function returns true; otherwise, it returns false.

Syntax

MAP_CONTAINS_KEY(map: map<K, V>, key: K): boolean

Parameters

• map: The map type data to be checked, where K represents the type of the key, and V represents the type of the value.
• key: The key to be queried, its type should match the key type K in the map.

Return Value

Returns a boolean value indicating whether the map contains the specified key.

Example

1. Determine if the map contains the key 'a':

SELECT MAP_CONTAINS_KEY(map('a', 1), 'a'); -- Returns true

2. Determine if the map contains the key 'b':

SELECT MAP_CONTAINS_KEY(map('a', 1), 'b'); -- Returns false

3. Suppose there is a map type data with key-value pairs ('name', 'Alice') and ('age', 25), determine if the map contains the key 'name':

SELECT MAP_CONTAINS_KEY(map('name', 'Alice', 'age', 25), 'name');-- Returns true

4. Similarly, check if the above map contains the key 'gender':

SELECT MAP_CONTAINS_KEY(map('name', 'Alice', 'age', 25), 'gender'); -- Returns false