Error: Cannot read properties of undefined (reading 'rows') while reading from s3

[melgo-tb]

I'm encountering an issue with the DuckDB driver in Metabase where I receive the following error when attempting to run a query:

Cannot read properties of undefined (reading 'rows')

-- Sample SQL query that triggers the error
SELECT * FROM 's3://sample_bucket/test/*.parquet';

Network Error response

{"database_id":2,"started_at":"2024-08-23T07:35:07.941803921Z","via":[{"status":"failed","class":"class clojure.lang.ExceptionInfo","error":"Error reducing result rows: Cannot invoke \"Object.getClass()\" because \"target\" is null","stacktrace":["--> query_processor.context.default$default_reducef$fn__53329.invoke(default.clj:60)","query_processor.context.default$default_reducef.invokeStatic(default.clj:57)","query_processor.context.default$default_reducef.invoke(default.clj:49)","query_processor.context$reducef.invokeStatic(context.clj:70)","query_processor.context$reducef.invoke(context.clj:63)","query_processor.context.default$default_runf$respond_STAR___53333.invoke(default.clj:69)","driver.sql_jdbc.execute$execute_reducible_query.invokeStatic(execute.clj:513)","driver.sql_jdbc.execute$execute_reducible_query.invoke(execute.clj:489)","driver.sql_jdbc.execute$execute_reducible_query.invokeStatic(execute.clj:497)","driver.sql_jdbc.execute$execute_reducible_query.invoke(execute.clj:489)","driver.sql_jdbc$fn__105083.invokeStatic(sql_jdbc.clj:63)","driver.sql_jdbc$fn__105083.invoke(sql_jdbc.clj:61)","query_processor.context$executef.invokeStatic(context.clj:60)","query_processor.context$executef.invoke(context.clj:49)","query_processor.context.default$default_runf.invokeStatic(default.clj:68)","query_processor.context.default$default_runf.invoke(default.clj:66)","query_processor.context$runf.invokeStatic(context.clj:46)","query_processor.context$runf.invoke(context.clj:40)","query_processor.reducible$identity_qp.invokeStatic(reducible.clj:15)","query_processor.reducible$identity_qp.invoke(reducible.clj:12)","query_processor.middleware.cache$maybe_return_cached_results$maybe_return_cached_results_STAR___69172.invoke(cache.clj:224)","query_processor.middleware.per....}

Frontend Error Response

error TypeError: Cannot read properties of undefined (reading 'rows')
    at index.js:19:14
    at Array.filter (<anonymous>)
    at O (index.js:16:6)
    at querying.js:198:11
    at u (runtime.js:63:40)
    at Generator._invoke (runtime.js:293:22)
    at Generator.next (runtime.js:118:21)
    at ie (app-main.bundle.js?58be9a4ec823cc62f9ff:2:1313746)
    at a (app-main.bundle.js?58be9a4ec823cc62f9ff:2:1313950)
    at app-main.bundle.js?58be9a4ec823cc62f9ff:2:1314011

The data is being returned in the network tab and when running the query outside metabase.

[melgo-tb]

Seems to be happening if any of the column value is empty or null in any of the parquet files. W
hen filtering out the columns which are not null, the data is being rendered.

[hrl20]

Thanks for the report and the workaround! Will look into handling null columns in the driver.