Convert arrays to strings

To convert an array into a single string, use the array_join function. The following standalone example creates a table called dataset that contains an aliased array called words. The query uses array_join to join the array elements in words, separate them with spaces, and return the resulting string in an aliased column called welcome_msg.

WITH
dataset AS (
  SELECT ARRAY ['hello', 'amazon', 'athena'] AS words
)
SELECT array_join(words, ' ') AS welcome_msg
FROM dataset

This query returns:

+---------------------+
| welcome_msg         |
+---------------------+
| hello amazon athena |
+---------------------+