feat(postgres): allow running multiple statements in no tx migrations

[adriangb]

Closes #3693

[abonander]

See #3574 for previous discussion.

I would prefer if the style matched the existing -- no-transaction annotation.

To make the annotation more selective, I would require it to match on a full line. That way someone can write a comment talking about it without accidentally introducing a statement break where they didn't intend to.

I also don't see much benefit in namespacing the annotations. I don't see much harm, but I also don't see much benefit.

Since the existing annotation isn't namespaced, adding a namespaced annotation (as well as using a different comment style) would just be confusing to the user.

[titaniumtraveler]

I also don't see much benefit in namespacing the annotations. I don't see much harm, but I also don't see much benefit.

My argument to add namespacing was mostly about making it clearer to the user that the annotation is in-fact an annotation. (-- no-transaction might get confused with a regular comment, -- sqlx:no-transaction definitely NOT.)

Also it implicitly communicates that the annotation comes from sqlx, which makes it easier to find out why it is there and what it does.

The last point is that I am reluctant about whitespaces in user interfaces, because they are far too easy to screw up and might lead to hard to diagnose errors.

Like when writing an annotation a user might accidentally add an tab character instead of space, or have two spaces instead of one. That is especially the case when dealing with a system that has relatively little insight into what is happening as this.

Since the existing annotation isn't namespaced, adding a namespaced annotation (as well as using a different comment style) would just be confusing to the user.

But yeah. In the end all those points don't have too much impact and just a few things I tend to be cautious of.

[adriangb]

@abonander any other changes other than renaming and matching the full line?

Do you generally think this implementation is more viable?

[adriangb]

@abonander I've renamed as per your request and made it only match a full line, including adding a test for the latter

[adriangb]

I confirmed that if I remove the \ns from the string split this gets split such that DROP TABLE does_not_exist; becomes runnable SQL that then fails to run.