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Rails validation, knowing which field is invalid?

I had a model that works great.

class Product < ActiveRecord::Base
  validates_format_of :field1, with: /\A[0-9\+\-\/\s]+\Z/, allow_nil: true
  validates_format_of :field2, with: /\A[0-9\+\-\/\s]+\Z/, allow_nil: true
end

some of my database entries are not valid. these are older records. I want to run a seed that finds these invalid entries

Product.all.each do |product|
  next if product.valid?
  # 
end

I want to clear attributes that are not valid. let me say that product 1 has a value test

in field1

which is invalid. now I want to clear this field and only this.

How do I find invalid fields? something likeproduct.field1.valid?

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3 answers


The Rails api allows you to get the error message with the method ActiveModel::Errors#get

:



Product.all.each do |product|
  product.valid? # => run validation callbacks

  product.errors.messages          # => {:field1=>["cannot be nil"]}
  product.errors.get(:field1)      # => ["cannot be nil"]
  product.errors.get(:field2)      # => nil

  # `include?` and `has_key?` works too(it aliases)
  product.errors.messages          # => {:field1=>["cannot be nil"]}
  product.errors.include?(:field1) # => true
  product.errors.include?(:field2) # => false

  # 
end
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It's easy to do, but there are a few things to remember about performance:

  • you don't want to just load all your products into memory and iterate over them,
  • if possible, you should not try to update them one by one.


This might be an acceptable solution:

invalid_ids = []

Product.find_each(batch_size: 200) do |product|
  if !product.valid?
    if product.errors.include?(:field_1)
      invalid_ids << product.id
    end
  end
end

Product.where(id: invalid_ids).update_all(field_1: nil)
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can you validate and validate the model and its attribute with valid? and also check errors

Product.all.each do |product|
 if  !product.valid? and !product.errors[field1].blank?
    ##do something if product is not valid and there is error in attribute that you may want to check
 end
end
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