activerecord-summarize VS rails-utils

This is cool! Re: multiple aggregates in one query, I wrote a Ruby gem that adds an even-more-powerful and multi-database-compatible version to ActiveRecord. (I have tested Postgres, MySQL, and SQLite are tested; others probably work, too.)

https://github.com/midnightmonster/activerecord-summarize

I made activerecord-summarize because this sort of reporting is something I end up needing over and over. From a reading, writing, and maintenance perspective, I like the way you just use normal ActiveRecord methods, and the shape of the data in the block is the shape of the data in the output. You can mostly write each part of the query as if it were the only thing you were querying.

If you need to perform multiple counts and/or sums on the same table, perhaps with different groupings and filters applied, activerecord-summarize can do many aggregate operations in one pass.

"summarize-like": I came up with early versions of the technique—surely not for the first time in the world, but new for me—several years ago for the sake of the Track1099 dashboard. But it was pages of hard-to-reason-about code, and it didn't occur to me that the techniques could fruitfully be generalized until last year (see summarize's predecessor, multi_count here), and it was in the last month or so that I worked out the more powerful and readable and less footgun-infested API of summarize—and its correspondingly enhanced implementation.