Overwrite primary key when importing with ActiveRecord

rubyonrails-talk
1

In my migrations I am importing data from a CSV file.

So i first create the table :

create_table :customers do |t| ... end

and then import data from a CSV into it. The CSV data allready contains values for the id field. My problem is that activerecord won't let me override the id field :

Customer.create(:id=>1000, :name=>.........)

It uses its own ID.

Does anyone know how I can solve this the correct way?

Any help is appreciated.

Thanks Chris

2

customer = Customer.new(:name => ...) do |c|    c.id = 1000 end customer.save

You can't set the id from the hash, but you can set it separately.

-Rob

Rob Biedenharn http://agileconsultingllc.com Rob@AgileConsultingLLC.com

3

Thanks Rob, you've saved me writing some ugly code to get around it.

What's the rational behind that behavior?

Chris

4

Well, you normally expect the :id to be auto-assigned by the database so it is prohibited (ignored) in the hash. Consider something like:

fred = Customer.find_by_name('fred') barney = Customer.new(fred.attributes) barney.save

As long as there are no other uniqueness constraints, barney should be saved and have his own id.

You can use attr_protected to pass this behavior to other columns of your choosing.

-Rob