Array of Sql values in Ruby

Question

in my Rails project I am trying to use the following query in a search form_tag

Student.joins(:courses).where(@params.joins(','), @values)

where params and values are dynamically constructed arrays since there are some optional parameters in the search. An example from my code:

  if params[:date_begin] != ''
    @params.push " courses.date_begin  >=  ? "
    @values.push params[:date_begin]
  end

The problem is the @values array is being considered as one argument and raises this error:

wrong number of bind variables (1 for 2)

How do I tell it to consider the array elements separately?

gotva · Accepted Answer · 2014-10-17 08:21:52Z

2

What about build query this way:

scope = Student.joins(:courses)

if params[:date_begin].present?
  scope = scope.where(" courses.date_begin  >=  ? ", params[:date_begin])
end

scope

answered Oct 17, 2014 at 8:21

gotva

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Comments

mikdiet · Accepted Answer · 2014-10-17 08:22:26Z

2

You need to splat array

Student.joins(:courses).where(@params.joins(','), *@values)

answered Oct 17, 2014 at 8:22

mikdiet

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I ended up using the above answer but yours too works great. Thanks a lot

This answer better answers the original question and IMO is cleaner

Matt · Accepted Answer · 2014-10-17 08:27:36Z

1

You can unpack the array like so:

Student.joins(:courses).where(@params.join('AND'), *@values)

(Note you also need to change joins to join and the comma to AND).

answered Oct 17, 2014 at 8:12

Matt

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