Update without validation.md

2016-10-31 Default scope in Rails

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+---
+title: Default scope in Rails
+tip-number: 30
+tip-username: Gokul M
+tip-username-profile: https://github.com/mgokul595
+tip-description: Using default scope in Rails Model
+
+---
+
+```ruby default_scope ``` in Rails will apply the conditions on all queries on the Model.
+
+class Test < ActiveRecord::Base
+  default_scope { where(started: true) }
+end
+
+```ruby
+Test.all # => SELECT * FROM tests WHERE started = true
+```
+
+To using more complex queries inside the ```ruby default_scope ``` you can declare the class method as use it as below:
+
+```ruby
+class Test < ActiveRecord::Base
+  def self.default_scope
+    # Query goes here
+  end
+end
+
+```
+
+
+The default scope is applied on the ```ruby new ``` and ```ruby create ```.
+If we initialize a new object it will set the value of the column to the default value that we specified in the ```ruby default_scope ```.
+
+For Example, 
+
+```ruby
+Test.new # Initializes a Test which contains started=true
+```
+
+So, be careful on using ```ruby default_scope```
+--

rails_tip/2016-10-31-Update without validation.md

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+---
+title: Disable model validation on update
+tip-number: 30
+tip-username: Gokul M
+tip-username-profile: https://github.com/mgokul595
+tip-description: Updating values in the Database without doing the model validation
+
+---
+
+
+
+
+Generally update_attributes method in rails will validate all fields eventhough it is not being updated.
+
+So, If we need to update the fields without doing such validations we can go with the below two methods:
+
+1. Updating the column one by one using update_attribute:
+
+```ruby
+@object.update_attribute(first_name: 'Rails')
+```
+
+This will validate & update only the name field and skip validation for other fields. 
+Now, Just think what if you need to update more columns. It cause more queries to be executed instead of updating in single query.
+
+2. Updating the column values without any validation:
+
+```ruby
+@object.assign_attributes(first_name: 'Ruby', last_name: 'Rails')
+@object.save(validate: false)
+
+```
+
+Using above method the validation of the columns can be skipped.
+
+--