Convert array data types - Amazon Athena
This documentation is a draft for private preview for regions in the AWS European Sovereign Cloud. Documentation content will continue to evolve. Published: January 10, 2026.

Convert array data types

To convert data in arrays to supported data types, use the CAST operator, as CAST(value AS type). Athena supports all of the native Presto data types.

SELECT
   ARRAY [CAST(4 AS VARCHAR), CAST(5 AS VARCHAR)]
AS items

This query returns:

+-------+
| items |
+-------+
| [4,5] |
+-------+

Create two arrays with key-value pair elements, convert them to JSON, and concatenate, as in this example:

SELECT
   ARRAY[CAST(MAP(ARRAY['a1', 'a2', 'a3'], ARRAY[1, 2, 3]) AS JSON)] ||
   ARRAY[CAST(MAP(ARRAY['b1', 'b2', 'b3'], ARRAY[4, 5, 6]) AS JSON)]
AS items

This query returns:

+--------------------------------------------------+
| items                                            |
+--------------------------------------------------+
| [{"a1":1,"a2":2,"a3":3}, {"b1":4,"b2":5,"b3":6}] |
+--------------------------------------------------+