Bulk update Records in single command after updating object column values

Question

I'm trying to figgure out to upate bulk of records with upate_all helper after while dynamically update columns value i.e

User.update_all(code: Digest::SHA1.hexdigest([Time.now, rand].join)[1..12]) which set unique values to all users.

User.update_all(code: Digest::SHA1.hexdigest([Time.now, rand].join)[1..12])

Answer 1

You can't actually do that with update_all.

update_all updates all the records with a single SQL query. So whatever your updating must either be static values or a SQL query thats evaluated in the database per row.

If you want generate a unique value per record in Ruby you need to iterate across the records and update each one individually:

User.find_each do |user|
  user.update!(code: Digest::SHA1.hexdigest([Time.now, rand].join)[1..12])
end

However a better solution altogether is most likely to generate the random code in your database.