fix(snowflake): convert parameters to qmark style

[hachichaud]

Change Summary

The parameters value passed from the backend can be incompatible
with pyformat mapping (dict or array values).
I use convert to qmark method that is already used on other connectors
Another way would be to flatten parameters, but it could still leave
some incompatible values (arrays of dict).

Checklist

• Unit tests for the changes exist
• Tests pass on CI and coverage remains at 100%
• Documentation reflects the changes where applicable

[raphaelvignes]

Thanks for this fix 👍

[davinov]

Nice 👍
A very small suggestion regarding delimiters used in examples:

[davinov]

%(...) is an old python syntax, I think we'd prefer to push Jinja' one in our connectors configs
Today, we're already replacing these automatically:

toucan-connectors/toucan_connectors/common.py

Line 78 in ce8ed06

# Replace param templating with jinja templating:

So my suggestion would be to use jinja {{ }} in your tests and documentation as well

[hachichaud]

les syntaxes compatibles avec execute de snowflake sont

• pyformat (%()s) => bug car on passe un dictionnaire parameters qui peut comporter des valeurs invalides.
• qmark => cest dans ce format qu'on convertit notre query pour bypasser le probleme du dictionnaire.

Par contre on ne peut pas utiliser jinja car ce n'est pas safe sur des requetes SQL
cf le code que tu pointes, qui est extrait de la methode no_sql_apply_parameters_to_query :

def nosql_apply_parameters_to_query(query, parameters, handle_errors=False):
    """
    WARNING : DO NOT USE THIS WITH VARIANTS OF SQL
    Instead use your client library parameter substitution method.
    https://www.owasp.org/index.php/Query_Parameterization_Cheat_Sheet
    """

on veut spécifiquement éviter le templating de cette manière.

[hachichaud]

@davinov you already had an issue on that actually! #303
^^

[hachichaud]

As a user i can use Snowflake live data queries on a chart or tile

Cannot use jinja for sql query parameters

[davinov]

We had a slack discussion about which style of param to use, let's open an issue/think more about it, but this PR is not the place for that.