feluelle commented on a change in pull request #6432: [AIRFLOW-5758] Support
the custom cursor classes for the PostgreSQL hook
URL: https://github.com/apache/airflow/pull/6432#discussion_r339300623
##########
File path: airflow/hooks/postgres_hook.py
##########
@@ -67,6 +68,13 @@ def get_conn(self):
password=conn.password,
dbname=self.schema or conn.schema,
port=conn.port)
+ if conn.extra_dejson.get('cursor', False):
+ if (conn.extra_dejson['cursor']).lower() == 'dictcursor':
+ conn_args['cursor_factory'] = psycopg2.extras.DictCursor
+ elif (conn.extra_dejson['cursor']).lower() == 'realdictcursor':
+ conn_args['cursor_factory'] = psycopg2.extras.RealDictCursor
+ elif (conn.extra_dejson['cursor']).lower() == 'namedtuplecursor':
+ conn_args['cursor_factory'] = psycopg2.extras.NamedTupleCursor
Review comment:
This looks like a [factory
pattern](https://en.wikipedia.org/wiki/Factory_method_pattern) can be of good
use here :)
```python
def _get_cursor(self):
_cursor = conn.extra_dejson['cursor'].lower()
if _cursor == 'dictcursor':
return psycopg2.extras.DictCursor
if _cursor == 'realdictcursor':
return psycopg2.extras.RealDictCursor
if _cursor == 'namedtuplecursor':
return psycopg2.extras.NamedTupleCursor
raise ValueError('Invalid cursor passed {}'.format(_cursor))
```
I also added complete validation (see the last line).
So after you have this factory you can just call it like that.
```python
if conn.extra_dejson.get('cursor', False):
conn_args['cursor_factory'] = self._get_cursor()
```
WDYT?
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