Question

I’ve looked everywhere for a similar error but couldn’t find a solution, so in desperation I’m posting here.

My controller has this:

def add_upc
        @upcs = Dvd.add_upc(params[:dogTag], params[:newUpc])
    end

and in the Model we have:

def self.add_upc(dogTag, newUpc)
    existingUpc = Dvd.find(dogTag).dvd_upc2title.find_by_upc(newUpc)
    if existingUpc.nil? 
        createdUpc = Dvd.find(dogTag).dvd_upc2title.create(:upc => newUpc)
        if createdUpc
            upcs = createdUpc
        else
            upcs = 'Error: nothing was created'
        end
    end
end

I’ve set up a view page to see what’s happening and I can see the object being created by createdUpc. I can also confirm that the parameters dogTag and newUpc are being passed correctly. Yet the record is not being added to the table.

Weirdly, this does work if I issue the Dvd.find(dogTag).dvd_upc2title.create(:upc => newUpc) command with the values substituted for the variables from the IRB.

Can’t figure out why this is not working. I’m new to Rails so don’t know what other error debugging I could use to figure out where the problem lies.

Ideas are welcome.

Thanks.

Edit:

Found the error thanks to RyanWilcox, it was the validation I had set up in the controller for UPC telling me that value already existed (even though UPCs are supposed to be unique. Is there a way to validate on a combination of 2 fields?

Answer 1

What I really like doing for situations like this (“why did this fail to save?”) is using create! instead of create.

This will throw an exception on error, with the failed validation’s text as the message of the exception. It makes problems like this obvious.