cumulative sum using mysql/rails

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?

Symbols and strings are not the same thing

Fred

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.

Nevermind I figured it out. I just need to_i