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.