Are the ActiveRecord find_or_create * methods fundamentally wrong?

Question

There are several methods: first_or_create_by, find_or_create_byand so on, which operate on the principle:

• talk to the database to try and find the material we need.
• If we did not find it, do it yourself.
• save it to db

Obviously, simultaneous calls to these methods can have both threads that cannot find what they want, and in step 3 a crash will unexpectedly occur.

Seems like the best solution is create_or_find

I.e:

• create reasonable uniqueness constraints in your database in advance.
• save something if you want to save it.
• if it worked, ok.
• if it does not work due to a RecordNotUnique exception, it is already there, fine, download it

, Rails, ( , ) create_or_find?

Answer 1

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Answer 2

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