embed the migration time in the file about dbmate

[amacneil]

I don't quite follow what the issue is. If timestamps were embedded in the files instead of a filename prefix, there would still be potential for them to be incorrect (or duplicates) if you copy a file and don't change the timestamp. Having them in the filename is nice because it means that migration files are listed in the order that they should be applied.

[cpwais]

One of my use cases is being able to create a migration file w/out having dbmate installed.

[amacneil]

Sorry, I still don't follow. You can easily create a new migration file without having dbmate installed. As far as naming convention goes, it's just version_description.sql, where version is in YYYYMMDDHHmmSS format, so you can generate names following that convention from any script etc.

The version number technically doesn't even need to be a timestamp, so you could just as easily choose to name your migrations 1_foo.sql, 2_bar.sql etc (keep in mind they will always be applied in alphabetic order, so you probably don't want to mix integers and timestamps). The only reason we use a timestamp by default is that it avoids conflicting version numbers being generated by multiple developers working on different branches of the same project.