cumulative sum using mysql/rails

rubyonrails-talk
1

I'm having an issue generating a cumulative sum by month in rails. This is what I have:

@results = Student.connection.select_all("SELECT        x1.MonthNo      , x1.MonthName      , x1.Added      , SUM(x2.Added) AS RunningTotal      FROM      (      SELECT        MONTH(passed_on) AS MonthNo      , MONTHNAME(passed_on) AS MonthName      , COUNT(*) AS Added      FROM students      WHERE passed_on >= '2009-09-23'      GROUP BY MONTH(passed_on)      ) AS x1      INNER JOIN (      SELECT        MONTH(passed_on) AS MonthNo      , MONTHNAME(passed_on) AS MonthName      , COUNT(*) AS Added      FROM students      WHERE passed_on >= '2009-09-23'      GROUP BY MONTH(passed_on)      ) AS x2      ON x1.MonthNo >= x2.MonthNo      GROUP BY x1.MonthNo;")

@result = @results.map{ |result| result[:RunningTotal] }

@result returns this:

[nil, nil]

even though @results returns this:

[{"RunningTotal"=>"1", "MonthName"=>"February", "Added"=>"1", "MonthNo"=>"2"}, {"RunningTotal"=>"11", "MonthName"=>"March", "Added"=>"10", "MonthNo"=>"3"}]

I would like @result to return this: [1,11]

Any suggestions thanks?

2

Symbols and strings are not the same thing

Fred

3

Frederick Cheung wrote:

I would like @result to return this: [1,11]

Any suggestions thanks?

Symbols and strings are not the same thing

Fred

--

But even this:

@result = @results.map{ |result| result['RunningTotal'] }

returns this:

["1", "11"]

Which is not helping me either, because I believe I need something like this: [1,11] for the chart I'm using.

4

Nevermind I figured it out. I just need to_i