Versioning a MySQL database when code base doesn't have a ORM

Question

I've been thinking about this problem for a while and have yet to come up with any stable/elegant ideas.

I know with MyISAM tables, you can get the table def update time but thats not so true with InnoDB and I've found its not even reliable to look at the .frm file for an idea of when the definition might have been modified.... nevermind if the dataset has been changed.

I had an idea of every 30 minutes mysqldumping the contents of a schema, breaking that apart with an AWK script, then diffing that to the last version... but that seems a little excessive and could be a problem if the dataset involved is large.

Answer 1

This reminds me of this question: How do you manage database revisions on a medium sized project with branches? but maybe I'm being to general...

http://odetocode.com/Blogs/scott/archive/2008/01/30/11702.aspx

The codebase I'm currently working on does not have an ORM yet we still use the solution based on the blog above. It works.

Answer 2

If you run mysqldump -d it only dumps the schema:

[gary.richardson@server ~]$ mysqldump -d -u root mysql user
-- MySQL dump 10.11
--
-- Host: localhost    Database: mysql
-- ------------------------------------------------------
-- Server version       5.0.45

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `user`
--

DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `Host` char(60) collate utf8_bin NOT NULL default '',
  `User` char(16) collate utf8_bin NOT NULL default '',
  `Password` char(41) character set latin1 collate latin1_bin NOT NULL default '',
  `Select_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Insert_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Update_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Delete_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Create_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Drop_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Reload_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Shutdown_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Process_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `File_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Grant_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `References_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Index_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Alter_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Show_db_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Super_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Create_tmp_table_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Lock_tables_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Execute_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Repl_slave_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Repl_client_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Create_view_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Show_view_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Create_routine_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Alter_routine_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `Create_user_priv` enum('N','Y') character set utf8 NOT NULL default 'N',
  `ssl_type` enum('','ANY','X509','SPECIFIED') character set utf8 NOT NULL default '',
  `ssl_cipher` blob NOT NULL,
  `x509_issuer` blob NOT NULL,
  `x509_subject` blob NOT NULL,
  `max_questions` int(11) unsigned NOT NULL default '0',
  `max_updates` int(11) unsigned NOT NULL default '0',
  `max_connections` int(11) unsigned NOT NULL default '0',
  `max_user_connections` int(11) unsigned NOT NULL default '0',
  PRIMARY KEY  (`Host`,`User`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='Users and global privileges';
/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;
/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;
/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2008-10-02 20:06:38

Then you could do your parsing.

There's another solution to your problem, but takes discipline. You can add a COMMENT field to columns and tables:

CREATE TABLE example (
  name varchar(32) COMMENT='Name of a person'
) COMMENT='example table';

I like to put a version number in there. You can tie that into your RCS:

CREATE TABLE example (
  name varchar(32) COMMENT='Name of a person'
) COMMENT='VERSION=1.2.3 example table';

Answer 3

Yeah, it's tough. That's why I use innodb. It's easier to do dump/import, we even put the schemas under VC.