Question

I am trying to grab two columns of data out of a database, using Ruby on Rails ActiveRecord calls and put them into a 2D JSON array for passing to the client.

I have it working for one column. Now I need to get it working for 2 columns.

This is what I have so far for the database call:

select("TOTAL").map{|x| x.TOTAL.ceil}

This is what I have for the controller:

@results = JSON.dump({ :totals => PerformanceResults.find_totals })

This gives me something like this:
{“totals” [145,132,863,693,372,74,838,91,18,172,84,90,373,161,160,173,1910,210,513,14,79,21,84,41,2630,0,93,150,2971]}

To get two columns, this is how I’m starting out, but it’s not going well:

Database call:

select("TOTAL, time_stamp ").map{|x| x.attributes.slice(:x.TOTAL.ceil, x.time_stamp)}

Its telling me “undefined method `TOTAL’ for :x:Symbol”, which I understand, but since I’m new to Ruby on Rails and also JSON, I thought I’d ask for some help in doing this…

My goal is to get this passed to the client: {“totals” [[‘timestamp’, data], [‘timestamp’, data], etc…. ]}

Answer 1

I have solved this on my own using the following for anyone looking for this solution in the future.

select("TOTAL, time_stamp ").map{|x| [x.TOTAL.ceil, x.time_stamp]}