Format characters in SQL comments raises error with SQLAlchemy connection

[derek-pyne]

Context:
Pandas read_sql is now raising a warning suggesting moving from a DB-API connection to a SQLAlchemy connection. Hence we are trying to make the switch.

Issue:
When using a SQLAlchemy connection, if the query has any format characters in it, then an error is raised. No issue with a DB-API connection.

Example query:

-- Format character in a comment %
SELECT 1

Likely Cause
When deciding whether to format the operation, PyHive checks if the given parameters is None.

PyHive/pyhive/presto.py

Line 256 in d199a1b

if parameters is None:

However, SQLAlchemy (1.4.31) always at least passes an empty dictionary (since it builds these params off of kwargs which default to an empty dict) so it is never None.

https://github.com/sqlalchemy/sqlalchemy/blob/2eac6545ad08db83954dd3afebf4894a0acb0cea/lib/sqlalchemy/engine/base.py#L1196

Likely Fix
Just need to also check if params is an empty dict:

if params is None or not params: