Class: AddNumberColumnToRecorderRevisions

Inherits:
ActiveRecord::Migration
  • Object
show all
Defined in:
lib/generators/recorder/templates/add_number_column_to_recorder_revisions.rb

Overview

This migration adds number column to the ‘revisions` table.

Instance Method Summary collapse

Instance Method Details

#down ⇒ Object 



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# File 'lib/generators/recorder/templates/add_number_column_to_recorder_revisions.rb', line 30

def down
  execute "    DROP TRIGGER update_recorder_revisions_number;\n  SQL\n\n  execute <<-SQL\n    DROP FUNCTION IF EXISTS get_recorder_revisions_number;\n  SQL\n\n  remove_column :recorder_revisions, :number\nend\n"

#up ⇒ Object 



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# File 'lib/generators/recorder/templates/add_number_column_to_recorder_revisions.rb', line 3

def up
  add_column :recorder_revisions, :number, :integer, :null => false, :default => 0

  execute "CREATE OR REPLACE FUNCTION get_recorder_revisions_number()\nRETURNS trigger AS\n$BODY$\nBEGIN\n  SELECT COALESCE(MAX(recorder_revisions.number), 0) + 1\n  INTO NEW.number\n  FROM\n    recorder_revisions\n  WHERE\n    recorder_revisions.item_type = NEW.item_type\n    AND recorder_revisions.item_id = NEW.item_id;\n\n  RETURN NEW;\nEND;\n$BODY$ LANGUAGE plpgsql;\n  SQL\n\n  execute <<-SQL\nCREATE TRIGGER update_recorder_revisions_number BEFORE INSERT ON recorder_revisions FOR EACH ROW\nEXECUTE PROCEDURE get_recorder_revisions_number();\n  SQL\nend\n"