rails change boolean value within a loop

Question

Hi everyone I need help with this method: I have a method that loops trough two models' data and compare them; if a match is found, I want to set the nih_pub match attribute to true then return all nih_pub that have match as false. it woks well if I use the commented if statement if nih.pubyear == "2003" and nih.pmid == "12538806", but it is not working with the looping.

below is the method i am using:

def compare
  nih_pub = NihPublication.where(user: current_user).all
  pubmed_pub = Publication.where(user: current_user).all

  nih_pub.each{ |nih|
    pubmed_pub.each {|pubmed|
      if nih.pubyear == pubmed.publication_year and  nih.pmid == pubmed.pubmed_id
      # if nih.pubyear == "2003" and  nih.pmid == "12538806"
        nih.match = true
        nih.save!
      end
    }
  }

  @missing = nih_pub.where(match: false)
end

Thank for your help

It's unclear: are you having an issue with the condition logic of the uncommented if (and the commented if worked correctly) OR are you having a problem with exiting the loop? — Michael Gaskill
– Michael Gaskill, Commented May 11, 2016 at 18:46
you can write return statement in if condition, so it return from loop and gives you @missing as output. — Amol Udage
– Amol Udage, Commented May 11, 2016 at 18:49
Sorry; the problem i am having is that this code is not getting executed nih.match = true nih.save!. if i use the commented if statement, everything works. — Idriss
– Idriss, Commented May 11, 2016 at 18:54
Thank everyone, it finally worked after I changed the if statement to this:if nih.pubyear == "#{pubmed.publication_year}" and nih.pmid == "#{pubmed.pubmed_id}" #if nih.pubyear == "2003" and nih.pmid == "12538806" nih.match = true nih.save! end — Idriss
– Idriss, Commented May 11, 2016 at 18:58

Chris Peters · Accepted Answer · 2016-05-11 18:57:06Z

1

This is likely a data type issue. You can compare data types in your console like this:

def compare
  nih_pub = NihPublication.where(user: current_user).all
  pubmed_pub = Publication.where(user: current_user).all

  nih_pub.each{ |nih|
    pubmed_pub.each { |pubmed|
      puts "nih.pubyear #{nih.pubyear.class.name}" 
      puts "pubmed.publication_year #{pubmed.publication_year.class.name}"
      puts "nih.pmid #{nih.pmid.class.name}"
      puts "pubmed.pubmed_id #{pubmed.pubmed_id.class.name}"

      if nih.pubyear == pubmed.publication_year and nih.pmid == pubmed.pubmed_id
      # if nih.pubyear == "2003" and  nih.pmid == "12538806"
        nih.match = true
        nih.save!
      end
    }
  }

  @missing = nih_pub.where(match: false)
end

If you see something like this:

nih.pubyear Integer
pubmed.publication_year String
nih.pmid Integer
pubmed.pubmed_id String

Then you know that you'll need to cast values when comparing them.

I suspect that you'll need to change your code to something like this (though this is only a guess and is based on the debug output I have listed above):

def compare
  nih_pub = NihPublication.where(user: current_user).all
  pubmed_pub = Publication.where(user: current_user).all

  nih_pub.each{ |nih|
    pubmed_pub.each { |pubmed|
      # Cast those strings to integers so you're comparing apples to apples.
      if nih.pubyear == pubmed.publication_year.to_i and nih.pmid == pubmed.pubmed_id.to_i
        nih.match = true
        nih.save!
      end
    }
  }

  @missing = nih_pub.where(match: false)
end

edited May 11, 2016 at 18:57

answered May 11, 2016 at 18:52

Chris Peters

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1 Comment

Idriss Over a year ago

Thank you! Now i am using .to_i instead of "#{}"

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