Rails: update_attribute vs update_attributes

Rails: update_attribute vs update_attributes

Object.update_attribute(:only_one_field, "Some Value")  Object.update_attributes(:field1 => "value", :field2 => "value2", :field3 => "value3")  

Both of these will update an object without having to explicitly tell AR to update.

Rails API says:

for update_attribute

Updates a single attribute and saves the record without going through the normal validation procedure. This is especially useful for boolean flags on existing records. The regular update_attribute method in Base is replaced with this when the validations module is mixed in, which it is by default.

for update_attributes

Updates all the attributes from the passed-in Hash and saves the record. If the object is invalid, the saving will fail and false will be returned.

So if I don't want to have the object validated I should use update_attribute. What if I have this update on a before_save, will it stackoverflow?

My question is does update_attribute also bypass the before save or just the validation.

Also, what is the correct syntax to pass a hash to update_attributes... check out my example at the top.

Answer by Salil for Rails: update_attribute vs update_attributes

Please refer to update_attribute. On clicking show source you will get following code

      # File vendor/rails/activerecord/lib/active_record/base.rb, line 2614  2614:       def update_attribute(name, value)  2615:         send(name.to_s + '=', value)  2616:         save(false)  2617:       end  

and now refer update_attributes and look at its code you get

      # File vendor/rails/activerecord/lib/active_record/base.rb, line 2621  2621:       def update_attributes(attributes)  2622:         self.attributes = attributes  2623:         save  2624:       end  

the difference between two is update_attribute uses save(false) whereas update_attributes uses save or you can say save(true).

Sorry for the long description but what I want to say is important. save(perform_validation = true), if perform_validation is false it bypasses (skips will be the proper word) all the validations assosciated with save.

For second question

Also, what is the correct syntax to pass a hash to update_attributes... check out my example at the top.

Your example is correct.

Object.update_attributes(:field1 => "value", :field2 => "value2", :field3 => "value3")  

or

Object.update_attributes :field1 => "value", :field2 => "value2", :field3 => "value3"  

or if you get all fields data & name in a hash say params[:user] here use just

Object.update_attributes(params[:user])  

Answer by concept47 for Rails: update_attribute vs update_attributes

I think your question is if having an update_attribute in a before_save will lead to and endless loop (of update_attribute calls in before_save callbacks, originally triggered by an update_attribute call)

I'm pretty sure it does bypass the before_save callback since it doesn't actually save the record. You can also save a record without triggering validations by using

Model.save false

Answer by Matt for Rails: update_attribute vs update_attributes

Tip: update_attribute is being deprecated in Rails 4 via Commit a7f4b0a1. It removes update_attribute in favor of update_column.

Answer by Kibet Yegon for Rails: update_attribute vs update_attributes

Also worth noting is that with update_attribute, the desired attribute to be updated doesn't need to be white listed with attr_accessible to update it as opposed to the mass assignment method update_attributes which will only update attr_accessible specified attributes.

Answer by Balachandar1887229 for Rails: update_attribute vs update_attributes

update_attribute

This method update single attribute of object without invoking model based validation.

obj = Model.find_by_id(params[:id])  obj.update_attribute :language, ?java?  

update_attributes

This method update multiple attribute of single object and also pass model based validation.

attributes = {:name => ?BalaChandar?, :age => 23}  obj = Model.find_by_id(params[:id])  obj.update_attributes(attributes)  

Hope this answer will clear out when to use what method of active record.

Answer by uma for Rails: update_attribute vs update_attributes

update_attribute and update_attributes are similar, but with one big difference: update_attribute does not run validations.

update_attribute is used to update record with single attribute.

Model.update_attribute(:column_name, column_value1)  

update_attribute is used to update record with multiple_attributes.

Model.update_attributes(:column_name1 => column_value1, :column_name2 => column_value2, ............)  

These two methods are really easy to confuse given their similar names and works. Therefore, update_attribute is being removed in favor of update_column.

Now, in rails4

you can use Model.update_column(:column_name, column_value1) at the place of Model.update_attribute(:column_name, column_value1)

click here to get more info about update_column

Answer by rogerdpack for Rails: update_attribute vs update_attributes

To answer your question, update_attribute skips pre save "validations" but it still runs any other callbacks like after_save etc. So if you really want to "just update the column and skip any AR cruft" then you need to use (apparently)

Model.update_all(...) see http://stackoverflow.com/a/7243777/32453

Answer by Ziv Galili for Rails: update_attribute vs update_attributes

Great answers. notice that as for ruby 1.9 and above you could (and i think should) use the new hash syntax for update_attributes:

Model.update_attributes(column1: "data", column2: "data")  

Answer by Shoaib Malik for Rails: update_attribute vs update_attributes

update_attribute simply update only one attribute of the model but we can pass multiple attributes in update_attributes method.

Example:

user = User.last

update_attribute

user.update_attribute(:status, "active") It pass the validation

update_attributes

user.update_attributes(first_name: 'update name', status: "active") it doesn't update if validation fails

Answer by Wojciech Bednarski for Rails: update_attribute vs update_attributes

Recently I ran into update_attribute vs. update_attributes and validation issue, so similar names, so different behavior, so confusing.

In order to pass hash to update_attribute and bypass validation you can do:

object = Object.new  object.attributes = {    field1: 'value',    field2: 'value2',    field3: 'value3'  }  object.save!(validate: false)  

Answer by adamliesko for Rails: update_attribute vs update_attributes

You might be interested in visiting this blog post concerning all the possible ways to assign an attribute or update record (updated to Rails 4) update_attribute, update, update_column, update_columns etc. http://www.davidverhasselt.com/set-attributes-in-activerecord/. For example it differs in aspects such as running validations, touching object's updated_at or triggering callbacks.

As an answer to the OP's question update_attribute does not by pass callbacks.

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