Fix for non-json-serializable values in BigQuery nested columns

CHANGELOG.md

@@ -23,6 +23,7 @@
 - Fix skipped node count in stdout at the end of a run ([#2095](https:/fishtown-analytics/dbt/issues/2095), [#2310](https:/fishtown-analytics/dbt/pull/2310))
 - Fix an issue where BigQuery incorrectly used a relation's quote policy as the basis for the information schema's include policy, instead of the relation's include policy. ([#2188](https:/fishtown-analytics/dbt/issues/2188), [#2325](https:/fishtown-analytics/dbt/pull/2325))
 - Fix "dbt deps" command so it respects the "--project-dir" arg if specified. ([#2338](https:/fishtown-analytics/dbt/issues/2338), [#2339](https:/fishtown-analytics/dbt/issues/2339))
+- Fix Object of type Decimal is not JSON serializable" error when BigQuery queries returned numeric types in nested data structures ([#2336](https:/fishtown-analytics/dbt/issues/2336), [#2348](https:/fishtown-analytics/dbt/pull/2348))
 
 ### Under the hood
 - Added more tests for source inheritance ([#2264](https:/fishtown-analytics/dbt/issues/2264), [#2291](https:/fishtown-analytics/dbt/pull/2291))

core/dbt/clients/agate_helper.py

@@ -4,6 +4,7 @@
 import datetime
 import isodate
 import json
+import dbt.utils
 from typing import Iterable, List, Dict, Union, Optional, Any
 
 from dbt.exceptions import RuntimeException
@@ -92,7 +93,7 @@ def table_from_data_flat(data, column_names: Iterable[str]) -> agate.Table:
  row = []
  for value in list(_row.values()):
  if isinstance(value, (dict, list, tuple)):
- row.append(json.dumps(value))
+ row.append(json.dumps(value, cls=dbt.utils.JSONEncoder))
  else:
  row.append(value)
  rows.append(row)

test/integration/022_bigquery_test/test_bigquery_repeated_records.py

@@ -26,8 +26,8 @@ def test__bigquery_fetch_nested_records(self):
  cast('Stonebreaker' as string) as lname
  ) as user,
  [
- struct(1 as val_1, 2 as val_2),
- struct(3 as val_1, 4 as val_2)
+ struct(1 as val_1, cast(2.12 as numeric) as val_2),
+ struct(3 as val_1, cast(4.83 as numeric) as val_2)
  ] as val
 
  union all
@@ -38,8 +38,8 @@ def test__bigquery_fetch_nested_records(self):
  cast('Brickmaker' as string) as lname
  ) as user,
  [
- struct(7 as val_1, 8 as val_2),
- struct(9 as val_1, 0 as val_2)
+ struct(7 as val_1, cast(8 as numeric) as val_2),
+ struct(9 as val_1, cast(null as numeric) as val_2)
  ] as val
  """
 
@@ -54,8 +54,8 @@ def test__bigquery_fetch_nested_records(self):
  '{"fname": "Johnny", "lname": "Brickmaker"}'
  ],
  "val": [
- '[{"val_1": 1, "val_2": 2}, {"val_1": 3, "val_2": 4}]',
- '[{"val_1": 7, "val_2": 8}, {"val_1": 9, "val_2": 0}]'
+ '[{"val_1": 1, "val_2": 2.12}, {"val_1": 3, "val_2": 4.83}]',
+ '[{"val_1": 7, "val_2": 8}, {"val_1": 9, "val_2": null}]'
  ]
  }