DataMapper first_or_create doesn't work… any ideas why?

I'm probably missing something here (more of those boring details might help) but if the metric exists, it's metric_input_file shouldn't be updated, i.e. , it's only set when new. If you're after updating then you can do first_or_create(msrun_id: tmp.Id).

Update(metric_input_file: @metricsfile) Or if not hitting the database twice is relevant, then m = Metric. First_or_new(msrun_id: tmp.Id) set..save..assign But if it's not being set on new models I don't see what would cause that from the code posted so far, more..? UPDATED Based on your new code, I'd say this is "a classic case" of a false DM save. I usually add the following line to an initialization section, e.g. , application.

Rb in Rails DataMapper::Model. Raise_on_save_failure = true Unfortunately, the exception raised never tells you why (there's a special place in hell for that choice, right next to people who talk in theaters. ) But it's typically one of: a slightly incorrect association definition a has/belongs_to that isn't "required: false" and isn't set putting the wrong datatype into a field, e.g. , a string into a decimal a validation failing If you want to post your model definitions, the problem may be spottable there.

I'm probably missing something here (more of those boring details might help) but if the metric exists, it's metric_input_file shouldn't be updated, i.e. , it's only set when new. If you're after updating then you can do .

First_or_create(msrun_id: tmp. Id). Update(metric_input_file: @metricsfile) Or if not hitting the database twice is relevant, then m = Metric.

First_or_new(msrun_id: tmp. Id) set..save..assign But if it's not being set on new models, I don't see what would cause that from the code posted so far, more..? UPDATED Based on your new code, I'd say this is "a classic case" of a false DM save. I usually add the following line to an initialization section, e.g. , application.

Rb in Rails. DataMapper::Model. Raise_on_save_failure = true Unfortunately, the exception raised never tells you why (there's a special place in hell for that choice, right next to people who talk in theaters.

) But it's typically one of: a slightly incorrect association definition a has/belongs_to that isn't "required: false" and isn't set putting the wrong datatype into a field, e.g. , a string into a decimal a validation failing If you want to post your model definitions, the problem may be spottable there.

In my reading of the website referenced, it says: "If the criteria you want to use to query for the resource differ from the attributes you need for creating a new resource, ... ... zoo = Zoo. First_or_create({ :name => 'The Glue Factory' }, { :inception => Time. Now }) This will search for a Zoo named ‘The Glue Factory’ and if it can’t find one, it will return a new Zoo instance with it’s name set to ‘The Glue Factory’ and the inception set to what has been Time.

Now at the time of execution. " – Ryanmt Jul 7 at 4:13 Sorry, I don't mean to be obtuse, but I'm not yet sure what you're getting at. The doc is saying a matching instance will be found using the left hash, but if nothing is found, the left and right hash will be merged (with right taking precedence) and used to mass assign the attributes of a new instance that'll also be saved.

– Yuri Gadow Jul 7 at 5:08 Haha, I like the way you put that. I'll add that line and post some more code... Thanks! – Ryanmt Jul 8 at 16:44.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.