Trouble getting fancy with ARRAY_AGG (DISTINCT ARRAY_AGG) #6743
Description
Describe the bug
ARRAY_AGG usage in SQL results in an error when used in conjunction with DISTINCT parameter alongside another aggregate field.
To Reproduce
- Establish example data:
CREATE TABLE example(id INT, parent_id INT, tag VARCHAR) AS VALUES
(1, 0, 'bob'),
(2, 0, 'cat'),
(3, 1, 'tom'),
(4, 1, 'cat'),
(5, 1, 'tom');- Execute query using
ARRAY_AGGandDISTINCTparameter:
SELECT
parent_id,
COUNT(id) AS count_of,
ARRAY_AGG(DISTINCT tag) AS tags
FROM example
GROUP BY parent_id;Executing the above results in the following message:
ArrowError(ExternalError(Internal("Inconsistent types in ScalarValue::iter_to_array. Expected Utf8, got List([tom,cat])")))
Expected behavior
Desired output should be similar to the following:
| parent_id | count_of | tags |
|---|---|---|
| 1 | 3 | [tom, cat] |
| 0 | 2 | [bob, cat] |
Additional context
Omitting either the COUNT field, or the DISTINCT clause in ARRAY_AGG, allows the query to complete successfully.
The above was initially discovered in v17.0.0 and verified to still be presenting in v26.0.0.