Class: Chicago::ETL::TableBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/chicago/etl/table_builder.rb

Overview

Builds ETL tables.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db) ⇒ TableBuilder

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of TableBuilder.



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# File 'lib/chicago/etl/table_builder.rb', line 12

def initialize(db)
  @db = db
end

Class Method Details

.build(db) ⇒ Object

Creates the necessary tables for the ETL process in the given database.



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# File 'lib/chicago/etl/table_builder.rb', line 7

def self.build(db)
  new(db).build
end

Instance Method Details

#build ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/chicago/etl/table_builder.rb', line 17

def build
  create_table :etl_batches do
    primary_key :id, :type => :integer, :unsigned => true
    timestamp   :started_at, :null => false, :default => :current_timestamp.sql_function
    timestamp   :finished_at, :null => true, :default => nil
    timestamp   :extracted_to, :null => true, :default => nil
    enum        :state, :null => false, :elements => %w{Started Finished Error}, :default => "Started"
  end

  create_table :etl_task_invocations do
    primary_key :id, :type => :integer, :unsigned => true
    integer     :batch_id, :unsigned => true, :null => false
    enum        :stage, :null => false, :elements => %w{Extract Transform Load}
    varchar     :name, :null => false
    timestamp   :started_at, :null => false, :default => :current_timestamp.sql_function
    timestamp   :finished_at, :null => true, :default => nil
    enum        :state, :null => false, :elements => %w{Created Started Finished Error}, :default => "Created"
    smallint    :attempts, :null => false, :unsigned => true

    index [:batch_id, :stage, :name], :unique => true
  end
end