Add support for multiple connections managed by migrations

[tobias-93]

References doctrine/migrations#1406, which fixes the filtering of the migrations table for the default connection but not for any other connections.
This PR applies the filter to each of the Doctrine connections.
Not sure what else is required in terms of tests/documentation etc.

[arderyp]

Is "my_custom_connection" on the example the name of a migration table? This example/naming confuses me

[tobias-93]

Is "my_custom_connection" on the example the name of a migration table? This example/naming confuses me

No, it is the name of a connection (see https://symfony.com/doc/current/reference/configuration/doctrine.html#doctrine-dbal-configuration). The name of the migrations table (of which there is only one per database/connection) is configured in the storage (see https://symfony.com/bundles/DoctrineMigrationsBundle/current/index.html#configuration)

[arderyp]

No, it is the name of a connection

How then does this relate to or fix the issue of the default dropping of the migrations table (the issues you posted this PR to as a solution)

Forgive my confusion, I must be missing something

[tobias-93]

With the latest update, the configuration value is no longer needed. I have verified it and it works correctly for multiple connections now.

[SenseException]

This feature looks testable (tests/DependencyInjection/DoctrineMigrationsExtensionTest.php)

[arderyp]

With the latest update, the configuration value is no longer needed. I have verified it and it works correctly for multiple connections now.

So... a return to the pre-break default behavior of assuming/expecting/ignoring a migration_versions table per connection? If not, would you mind explaining more?

[tobias-93]

@arderyp indeed, the configured migrations table name is filtered in the migrations context. Pre-break this needed to be configured in the DBAL context if I'm not mistaken, which is now done automatically

[arderyp]

Thanks @tobias-93

I'm not entirely clear on your latest comment. Here is how I remember the series of events

Years ago I had to configure doctrine migrations to ignore my migrations table. Then eventually DM changed something such that the migrations table that was configured was ignored by default. Then, something broke, and required me to explicitly ignore the migrations tables again, despite them being explicitly configured (and thus eligible to discovering and ignoring).

Are you saying that this PR will make it so DM automatically detects configured migration tables and ignores them again, automatically... no need for explicitly filtering them out?

If so, that's great!

[tobias-93]

@arderyp in fact it is already filtered for the default connection, so if you're just using one connection with migrations you can simply remove the filter and enjoy! This PR makes sure this auto-filter is also applied to any additional connection which is defined in the DBAL config.

[Pixelshaped]

Having multiple connections and entity managers, I get the DROP TABLE doctrine_migration_versions; on doctrine:migration:diff. Thanks for your PR, waiting for the release :)

[greg0ire]

Thanks @tobias-93 !