Rails-创建记录或更新记录的最有效方法是什么（如果记录存在）？

Question

I have a MySQL relation with 3 primary keys called golden_results : platform_id, release_id, configuration_id

All of those are also foreign keys to other relations.

Now, I also have a rake task than scans every week or so the options, and fills this relation with proper information.

There are two cases:

1. the record with this three-some-key already exists: in this case I would like to update the current record with refreshed data. I've read that there once was a create_or_update method which isn't exists now.

2. the record doesn't exists: in this case I'd like to add this record with the data.

As this may be a big access to the DB, the ideal way to achieve this would be to insert the records as transaction . I've read this article which suggest the most proper way of achieving this from performance perspective.

My current code looks like this (this, of course, isn't best solution as described...):

def add_golden_result record

response= 
    GoldenResult.find_or_create_by(platform_id: record.platform_id, release_id: record.release_id, configuration_id: record.configuration_id) do |r|
        r.asr_ndr_bandwidth         =   record.asr_ndr_bandwidth
        r.normalized_ndr_bandwidth  =   record.asr_ndr_bandwidth/(10.0*record.ndr_cpu)
        r.asr_latency_bandwidth     =   record.asr_latency_bandwidth
    end

response.update(
    asr_ndr_bandwidth: record.asr_ndr_bandwidth, 
    normalized_ndr_bandwidth: record.asr_ndr_bandwidth/(10.0*record.ndr_cpu),
    asr_latency_bandwidth: record.asr_latency_bandwidth
    )

end

Can anyone suggest a solution? (hopefully one that doesn't asks me to write my own query, so that the rails convention will keep on being preserved using ActiveRecord).

BTW- I'm using Rails 4, with mysql2 driver.

Thanks!

Answer 1

Try find_or_create_by ( http://apidock.com/rails/v4.0.2/ActiveRecord/Relation/find_or_create_by ).

record = GoldenResult.find_or_create_by( platform_id: platform_id, 
         release_id: release_id, configuration_id: configuration_id ) do |record|
  # fill in additional data for a new record if needed
end

Answer 2

This is not an unusual problem:

ClassName.find_or_create_by(foo: "foo", bar: "bar", f_b_id: 1).tap do |record|
  # This runs the code on ether the found or created record
  # #tap forces a block to be ran. 
  # The object of the block is the object that it's called on.
  record.other_field = "other data"
  record.even_more_data = "even more data"
  record.save
end