Amazon Athena
User Guide

Converting 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}] | +--------------------------------------------------+