feat: support multiple queries for clickhouse using up/down-sections

[dsagoyaneleven]

Currently, ClickHouse does not support executing multiple queries. However with these changes, it becomes possible.
We just put each separate up- or down-query in sections. The sections are optional.

[amacneil]

This seems like a nice solution that avoids full sql parsing.

Imo we could avoid the separate -- migrate:up-section and just allow multiple -- migrate:up blocks?

Curious to hear what others think.

[dossy]

Imo we could avoid the separate -- migrate:up-section and just allow multiple -- migrate:up blocks?

+1 on allowing multiple -- migrate:up (and, similarly, -- migrate:down) blocks.

[dsagoyaneleven]

Imo we could avoid the separate -- migrate:up-section and just allow multiple -- migrate:up blocks?

This might work also.

Maybe we need just keep in mind this detail:

That we have -- migrate:up and -- migrate:down and we can set migration options pro up or pro down.
So the idea was that we define one up block (for example) with a specific migration option, let's say transaction=true, and run multiple -- migrate:up-section queries, if one fails, then you can do rollback.

You can also have multiple -- migrate:up but then it's not very clear how to apply migration options, should every -- migrate:up has it's own, or repeat if it's more than one (same question for --migrate:down).

So it's just a question of implementation for sure.

[dossy]

You can also have multiple -- migrate:up but then it's not very clear how to apply migration options, should every -- migrate:up has it's own, or repeat if it's more than one (same question for --migrate:down).

Personally, I would expect that migration options specified on a -- migrate:up section only applies to that single section.

[thecodedrift]

Curious to hear what others think.

Chiming in as a current goose user who couldn't use dbmate earlier because of the multiple clickhouse queries issue.

Multiple --migrate:up and --migrate:down blocks, each with their own settings, is perfectly reasonable. It's also IMO the simplest to explain: you can break multiple statements up by adding additional migrate directives to your file. It's your responsibility to manage a partial migration in this situation, and only recommended when it's unreasonable or impossible to do multiple statements within a single up or down directive.

For me, It turns seven clickhouse migrations into a single file and has zero impact on the postgres migration files.

[keyur-scogo]

+1 Any timeline to expect for this to release?

[dossy]

Rework the PR to not introduce migrate:up-section and migrate:down-section, and instead change ParsedMigration's Up from string to []string and UpOptions from ParsedMigrationOptions to []ParsedMigrationOptions, and similar for Down and DownOptions.

The tests are lacking cases that demonstrate the ability to specify different migration options per each up or down block.

The PR is also missing updates to the documentation that document this feature, as well.