# File lib/active_record/connection_adapters/mysql_adapter.rb, line 787 def quoted_columns_for_index(column_names, options = {}) length = options[:length] if options.is_a?(Hash) case length when Hash column_names.map {|name| length[name] ? "#{quote_column_name(name)}(#{length[name]})" : quote_column_name(name) } when Fixnum column_names.map {|name| "#{quote_column_name(name)}(#{length})"} else column_names.map {|name| quote_column_name(name) } end end