Rails find getting ActiveRecord::RecordNotFound

Question

I have a table that includes a "belongs to" in the model. The table includes the xx_id field to link the two tables.

But, sometimes the xx_id is going to be blank. When it is, I get ActiveRecord::RecordNotFound. I don't want an error - I just want a blank display for this field.

What do you suggest?

Answer 1

Rails will always raise an ActiveRecord::RecordNotFound exception when you use the find method. The find_by_* methods, however, return nil when no record is found.

The ActiveRecord documentation tells us:

RecordNotFound - No record responded to the find method. Either the row with the given ID doesn't exist or the row didn't meet the additional restrictions. Some find calls do not raise this exception to signal nothing was found, please check its documentation for further details.

If you'd like to return nil when records cannot be found, simply handle the exception as follows:

begin
  my_record = Record.find params[:id]
rescue ActiveRecord::RecordNotFound => e
  my_record = nil
end

Answer 2

Can't you write

my_record = Record.find(params[:id]) rescue nil

Answer 3

Record.find_by(id: params[:id])

returns Record object if it is found or nil if it is not.

Answer 4

When you call find, you'll obtain an array. When array does not contain objects, count is zero.

items = Store.find(:all, :conditions => {:resource_id => item.id})
if item.count == 0 puts " !not found for item id#{item.id}"

or

if item.nil? puts " !not found for item id#{item.id}"