drop_column (SQL::TableModifier)

    # File lib/dm-migrations/sql/table_modifier.rb, line 20
        def drop_column(name)
          # raise NotImplemented for SQLite3. Can't ALTER TABLE, need to copy table.
          # We'd have to inspect it, and we can't, since we aren't executing any queries yet.
          # TODO instead of building the SQL queries when executing the block, create AddColumn,
          # AlterColumn and DropColumn objects that get #to_sql'd
          if name.is_a?(Array)
            name.each{ |n| drop_column(n) }
          else
            @statements << "ALTER TABLE #{quoted_table_name} DROP COLUMN #{quote_column_name(name)}"
          end
        end