AttributeError: module 'target_snowflake.sql' has no attribute 'Identifier'

[franloza]

Hello!

I think I've found a bug when trying to set a column as nullable. I changed the tap schema to accept NULL and now the target is raising an AttributeError. The problem may be in this function:

https://github.com/datamill-co/target-snowflake/blob/master/target_snowflake/snowflake.py#L579-L587

Traceback

target-snowflake | ERROR Exception writing records
target-snowflake | Traceback (most recent call last):
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/snowflake.py", line 150, in write_batch
target-snowflake |     written_batches_details = self.write_batch_helper(cur,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/sql_base.py", line 822, in write_batch_helper
target-snowflake |     remote_schema = self.upsert_table_helper(connection,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/sql_base.py", line 499, in upsert_table_helper
target-snowflake |     self.make_column_nullable(connection,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/snowflake.py", line 586, in make_column_nullable
target-snowflake |     table_name=sql.Identifier(table_name),
target-snowflake | AttributeError: module 'target_snowflake.sql' has no attribute 'Identifier'
target-snowflake | CRITICAL ('Exception writing records', AttributeError("module 'target_snowflake.sql' has no attribute 'Identifier'"))
target-snowflake | INFO MillisLoggingCursor: 98 millis spent executing: ROLLBACK
target-snowflake | Traceback (most recent call last):
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/snowflake.py", line 150, in write_batch
target-snowflake |     written_batches_details = self.write_batch_helper(cur,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/sql_base.py", line 822, in write_batch_helper
target-snowflake |     remote_schema = self.upsert_table_helper(connection,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/sql_base.py", line 499, in upsert_table_helper
target-snowflake |     self.make_column_nullable(connection,
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/snowflake.py", line 586, in make_column_nullable
target-snowflake |     table_name=sql.Identifier(table_name),
target-snowflake | AttributeError: module 'target_snowflake.sql' has no attribute 'Identifier'
target-snowflake | 
target-snowflake | During handling of the above exception, another exception occurred:
target-snowflake | 
target-snowflake | Traceback (most recent call last):
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/bin/target-snowflake", line 8, in <module>
target-snowflake |     sys.exit(cli())
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/__init__.py", line 57, in cli
target-snowflake |     main(args.config)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/__init__.py", line 51, in main
target-snowflake |     target_tools.main(target)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/target_tools.py", line 28, in main
target-snowflake |     stream_to_target(input_stream, target, config=config)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/target_tools.py", line 77, in stream_to_target
target-snowflake |     raise e
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/target_tools.py", line 70, in stream_to_target
target-snowflake |     state_tracker.flush_streams(force=True)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/stream_tracker.py", line 47, in flush_streams
target-snowflake |     self._write_batch_and_update_watermarks(stream)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_postgres/stream_tracker.py", line 67, in _write_batch_and_update_watermarks
target-snowflake |     self.target.write_batch(stream_buffer)
target-snowflake |   File "/project/.meltano/loaders/target-snowflake/venv/lib/python3.8/site-packages/target_snowflake/snowflake.py", line 164, in write_batch
target-snowflake |     raise SnowflakeError(message, ex)
target-snowflake | target_snowflake.exceptions.SnowflakeError: ('Exception writing records', AttributeError("module 'target_snowflake.sql' has no attribute 'Identifier'"))