class AddLikes < ActiveRecord::Migration
  def self.up
    result = execute("SELECT version FROM schema_migrations WHERE version = '201110319172136'")
    if result.count > 0
      execute("DELETE FROM schema_migrations WHERE version = '201110319172136'")
    else
      create_table :likes do |t|
        t.boolean :positive, :default => true
        t.integer :post_id
        t.integer :author_id
        t.string :guid
        t.text :author_signature
        t.text :parent_author_signature
        t.timestamps
      end
      add_index :likes, :guid, :unique => true
      add_index :likes, :post_id
      add_foreign_key(:likes, :posts)
      add_foreign_key(:likes, :people, :column =>  :author_id)
    end
  end

  def self.down
    drop_table :likes
  end
end