Add use_batch_mode parameter to sqlalchemy create_engine

[argolo]

I would like to add use_batch_mode parameter or sqlalchemy create_engine. Is there something that allows this or can I work on a pull request? What would be the best approach in the case of pull request?

Source on use_batch_mode:

• http://docs.sqlalchemy.org/en/latest/changelog/migration_12.html#dialect-improvements-and-changes-postgresql
• http://initd.org/psycopg/docs/extras.html#fast-execution-helpers
• https://stackoverflow.com/questions/38369569/insert-data-into-postgresql-from-python

[nirizr]

Hi,
I also have that issue and I would also like it fixed, but in the meanwhile I found a simple work-around that helped me.

by accessing the engine's dialect you can manually set the member responsible for using the match_mode after the engine and dialect have been created. Assuming db = SQLAlchemy(flask_app), all you need to do is add the following line afterwards:

db.engine.dialect.psycopg2_batch_mode = True

[argolo]

Thank you, @nirizr ! I'll try that.

[moi90]

Thanks @nirizr !

However, Flask-SQLAlchemy should really allow passing keyword parameters to create_engine. The simplest solution would be a configuration key, right?

[nirizr]

Yes. Probably. This is a workaround, not a fix :)

…

On Wed, Aug 1, 2018, 01:15 moi90 ***@***.***> wrote: Thanks @nirizr <https://github.com/nirizr> ! However, Flask-SQLAlchemy should really allow passing keyword parameters to create_engine. The simplest solution would be a configuration key, right? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#594 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ADdqV3J5fnNQwmyJaq111UY-JGWfq4GFks5uMWOkgaJpZM4SJkfk> .

[grim7reaper]

Hi,

I also had the need to specify extra kwargs to the underlying call to create_engine (to be more specific, I needed to customize the isolation level).

To do so, I used the method apply_driver_hacks (documented here):

This method is called before engine creation and used to inject driver specific hacks into the options. The options parameter is a dictionary of keyword arguments that will then be used to call the sqlalchemy.create_engine() function.

What you need to do is to define your own class that overload this method:

class SQLAlchemyCustomized(flask_sqlalchemy.SQLAlchemy):
    def apply_driver_hacks(self, app, info, options):
        options['use_batch_mode'] = True
        super().apply_driver_hacks(app, info, options)

And then use your class instead of the default one:

# Replace "db = SQLAlchemy(app)" by
db = SQLAlchemyCustomized(app)

Hope that helps :)

[rsyring]

This will be resolved by: #166