sum(:a_field) does not work

[leadbaxter]

It could just be me (first time using CDQ) but I can't get sums to work.

I have a pretty simple Weather entity. No matter what I do, I get the same error.

schema '0002 added_extras' do
  entity 'Weather' do
    datetime :date,     optional: false
    string   :inches,   optional: false    # could be '1 1/2' or it could be '1.5'
    string   :month,    optional: true     # month number, like '06' or '12'
    float    :inches_f, optional: true      # is 1.5, 0.25, etc.
  end
end

# The field :inches_f is a float with inches of rainfall
# The field :month is a month, like '06' or '12'
Weather.where(:month).eq(month).sum(:inches_f)
Weather.sum(:inches).where(:month).eq(month)
Weather.sum(:inches_f)

After that, I would assume I could write:

total_for_month = Weather.where(:month).eq(month).sum(:inches_f).first.sum_of_inches_f

Here's the error resulting from any of the above queries:

targeted_query.rb:154:in `method_missing:': undefined method `sum' for <CDQ::CDQTargetedQuery:0x10adbe1e0 ...> (NoMethodError)

[kemiller]

I'm not sure why you're calling first on the result of sum. Sum should give you the totally all by itself. What precisely are you doing to get that error?

[leadbaxter]

The only reason I'd be calling first is because I don't know what I'm doing. I haven't been able to explore any further because the error stops me. If I could, then I would soon learn whether I needed to write .first or not!

I can reproduce the error as simply as:

Weather.sum(:inches_f)

Other than that, I'm doing all the CRUD operations, sorting, and grouping - the whole nine yards. But sum() does not work for me at all. Incidentally, I hit some other of the aggregate type functions that failed. But it was like 2am and I don't remember which ones.

[kemiller]

I guess I'm not sure what to say. You're right it should work, and that's an odd error. If you can put up a repo that will reliably produce that we can take a look.

[leadbaxter]

leadbaxter/cdq_test

I included a bunch of unit tests to show the problem, plus some other problems I was telling you I found, as well as a bunch of sanity tests (mostly because I wanted to see whether a lot of the Enumerable methods worked or not.)

A couple of things you may or may not care about when installing:

1. I use RVM so there is a .ruby-gemset / .ruby-version pair of files (in case you care.)
2. I added CDQ.cdq.reset! to the "before" section of tests to make sure the database starts off empty (if there was a crash, it didn't clear it out.)
3. In the Rakefile, the id is com.leadbaxter.cdq_test (in case you care.)

If you need any more information just give me a holler!

Thanks for looking at it.

[kemiller]

Oh, OK. I see what's going on. You're using features that are in head, but not in the latest gem. I need to release v 1.0.3 apparently.

[leadbaxter]

That fixes all but the last two of my tests, the ones using the indexing. I modeled mine after what I saw in your tests, but it still didn't work.

Weather.sort_by(:readings)[0]

Any ideas?

[leadbaxter]

I figured out my problem... can't use negative indexes. Makes sense.

Weather[2]

instead of

Weather[-1]

works perfectly. I have 25 successful tests running.

Thanks for helping and for jumping right on it!