Wrapping in transaction(s) for DBs that support it / SQL templating

[t3hmrman]

Some databases support DDL in transactions, and for those it's almost strictly better for migrations to be all-or-nothing, as in:

BEGIN TRANSACTION;

CREATE TABLE some_table (...);

CREATE INDEX some_table_idx (...);

COMMIT TRANSACTION;

It would be nice to have the created files have BEGIN TRANSACTION at the top for Postgres.

While the quick fix might be just adding the lines (maybe having them commented out), a more general one might be allowing the specification of a static template for up/down migration migrations, then I can just add the file, make sure to point to it in my config and then when I make a migration it will have the bits I want in it.

[mmkal]

@t3hmrman this is now possible in v0.8 using singleTransaction. It's not yet documented, but it should do what you're suggesting.

This test shows an example usage.

[t3hmrman]

Thanks @mmkal -- I've been getting along just fine with migrator by using the BEGIN and COMMIT, and will switch to using singleTransaction -- have used migrator on a couple of projects now and it's fantastic, thanks for all the hard work!