Provide a DbalStore

[stof]

It would be great to support a DbalStore taking a DBAL connection as dependency and handling internally the appropriate storage depending on the platform. This would allow projects to take full benefit of the DBAL abstraction (as long as their platform is among the ones supported by the store).
Note that this would also avoid the issue of #84 for that store.

[chr-hertel]

Yup, get the idea, and having a DbalStore would be great. Goal for the current MariaDB and Postgres store was to avoid a hard dependency to DBAL, since that would be too much in my point of view. But you're also correct that for a lot of Symfony projects DBAL is around anyways, and just sitting on top of that would be easy.

Having both, a DbalStore and engine-specific stores, not relying on Dbal, would be the best scenario. I would expect some duplications there, but let's see.