Sqitch: Now with SQLite Support
This week I released Sqitch v0.961. There are a number of great new features v0.95x, including the beginning of two features I’ve had in mind since the beginning: VCS integration and support for multiple databases.
First the VCS integration. This comes in the form of the new
command, which automatically makes database changes for you when you change VCS
branches. Say you have two branches, “widgets” and “big-fix”, and that their
Sqitch plans diverge. If you’re in the “widgets” branch and want to switch to
“big-fix”, just run
sqitch checkout big-fix
Sqitch will look at the “big-fix” plan, figure out the last change in common with “widgets”, and revert to it. Then it checks out “big-fix” and deploys. That’s it. Yes, you could do this yourself, but do you really remember the last common change between the two branches? Do you want to take the time to look for it, then revert, check out the new branch, and deploy? This is exactly the sort of common developer task that Sqitch aims to take the pain out of, and I’m thrilled to provide it.
You know what’s awesome, though? This feature never occurred to me. I didn’t come up with it, and didn’t implement it. No, it was dreamt up and submitted in a pull request by Ronan Dunklau. I have wanted VCS integration since the beginning, but had yet to get ‘round to it. Now Ronan has jumpstarted it. A million thanks!
One downside: it’s currently Git-only. I plan to add infrastructure for supporting multiple VCSes, probably with Git and Subversion support to begin with. Watch for that in v0.970 in the next couple months.
The other big change is the addition of SQLite support alongside the existing
PostgreSQL support. Fortunately, I was able to re-use nearly all the code, so
the SQLite adapter is just a couple hundred lines long. For the most part,
Sqitch on SQLite works just like on PostgreSQL. The main difference is that
Sqitch stores its metadata in a separate SQLite database file. This allows one
to use a single metadata file to maintain multiple databases, which can be
important if you use multiple databases as schemas pulled into a single
Curious to try it out? Install Sqitch from CPAN or via the Homebrew Tap and then follow the new Sqitch SQLite tutorial.
Of the multitude of other Changes, one other bears mentioning: the new
command. This command is just like
log, except that it shows what is in the
plan file, rather than what changes have been made to the database. This can be
useful for quickly listing what’s in a plan, for example when you need to
remember the names of changes required by a change you’re about to
--oneline option is especially useful for this functionality. An example from
the tutorial’s plan:
> sqitch plan --oneline In sqitch.plan 6238d8 deploy change_pass d82139 deploy insert_user 7e6e8b deploy pgcrypto 87952d deploy delete_flip @v1.0.0-dev2 b0a951 deploy insert_flip 834e6a deploy flips d0acfa deploy delete_list 77fd99 deploy insert_list 1a4b9a deploy lists 0acf77 deploy change_pass @v1.0.0-dev1 ec2dca deploy insert_user bbb98e deploy users ae1263 deploy appschema
I personally will be using this a lot, Yep, scratching my own itch here. What itch do you have to scratch with Sqitch?
In related news, I’ll be giving a tutorial at PGCon next month, entitled “Agile Database Development”. We’ll be developing a database for a web application using Git for source code management, Sqitch for database change management, and pgTAP for unit testing. This is the stuff I do all day long at work, so you can also think of it as “Theory’s Pragmatic approach to Database Development.” See you there?
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