ruby - How are these methods like create_table available in the Rails Migration class? -

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How the methods and classes are defined in Ruby, and how to read an API document, this is a question. In short: how the create_table method is defined / imported / inherited, so it is available in the code in ActiveRecord :: migration : 

  Create Class Products & lt; ActiveRecord :: Migration Def up_table: products do | T | T.string: name ...   
 Coming from the world of Java, I was hoping to provide links to base classes or mixes where everything was defined. But if I look at the  migration  page, I see some handwritten documents, but there is no link from the most detailed, official definition of  create_table . I used Google to find it in  ActiveRecord :: ConnectionAdapters :: SchemaStatements , but even seeing the source code of two files:  
 
 < / P> 
 I do not think how to  create_table  to  migrate .  Itemprop = "text"> 
 These methods are dynamically created in this class:  
 They are dynamically adding to the  CommandRecorder  class The lines are then:  
  Class migration autoload: CommandRecorder, 'active_record / migrations / command_recorder'   
 This provides for the migration class.

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