gistfile1.rb

require "active_record"

ActiveRecord::Base.establish_connection(
  :adapter => "sqlite3",
  :dbfile  => "test.sqlite3"
)

ActiveRecord::Schema.define do
  create_table "things" do |t|
    t.column "flag", :bool
  end
  remove_column "things", "flag"
end

system "echo '.schema things' | sqlite3 test.sqlite3"

# -- create_table("things")
#    -> 0.0702s
# -- remove_column("things", "name")
#    -> 0.0106s
# CREATE TABLE "things" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL);