I am pretty new to Ruby on Rails and I'm having some problems. I have already checked out: This stackoverflow question about cloning a model
I am creating a new method for a model that looks like this:
def copy(new_period)
@copy = self.clone
@copy.report_id = Report.maximum(:report_id).next
@copy.period_id = new_period
@copy.save
end
I am trying to create a new instance of report that can be moved to the next year(period). When I run this method in irb I get:
irb(main):003:0> c = r.copy(5)
(1.8ms) SELECT MAX("reports"."report_id") AS max_id FROM "reports"
(0.8ms) BEGIN
(1.0ms) UPDATE "reports" SET "period_id" = 5 WHERE "reports"."report_id" = 438
(1.1ms) COMMIT
=> true
When I look in pgAdmin the new report isn't there. Could someone please explain to me what is going on when the console says "commit" and "=> true"? Does this not mean it has saved to the database?
You're updating the old model because the id of the model is still set. You can see that because your console shows an UPDATE instead of an INSERT statement.
From the Docs for ActiveRecord::Core#clone:
Identical to Ruby's clone method. This is a “shallow” copy. Be warned that your attributes are not copied. That means that modifying attributes of the clone will modify the original, since they will both point to the same attributes hash. If you need a copy of your attributes hash, please use the dup method.
ActiveRecord::Core#dup however results in a new record:
Duped objects have no id assigned and are treated as new records. Note that this is a “shallow” copy as it copies the object's attributes only, not its associations. The extent of a “deep” copy is application specific and is therefore left to the application to implement according to its need. The dup method does not preserve the timestamps (created|updated)_(at|on).
About your side questions:
BEGIN and COMMIT are used to start and end transactions in SQL.true is the result of r.copy, which implicitly returns the value of @copy.safe, which returns true if the model was saved successfully.