It’s no secret that I’m a massive fan of the Coldfusion on Wheels framework.. and there are a couple of tools that I use in my deployment process that are invaluable to me.

One of those is the DBMigrate plugin. I recently came up with a way to automatically migrate to the latest database version when the application first starts.

This can be useful/essential when:

• Your deployment process doesn’t use post-deploy hooks
• You want to make your application more portable
• You want to simplify your deployment script

Essentially, it calls a couple of the plugin’s methods whilst doing a little array-fu.

/events/onapplicationstart.cfm

<cfscript>
// migrate database
_dbm = {}
// create a pointer to the dbmigrate plugin
_dbm.plugin = application.wheels.plugins.dbmigrate
// create an array of available migrations sorted by version in descending order
_dbm.available = []
for(item in _dbm.plugin.getAvailableMigrations()){
_dbm.available.Append(item.version)
}
ArraySort(_dbm.available, "numeric", "desc")
// migrate to the most recent version
_dbm.plugin.migrateTo(_dbm.available[1])
</cfscript>

There are a few caveats:

• It will execute every time the application loads OR is manually reloaded via the reload=true parameter (though it’s fairy lightweight when there are no migrations to execute)
• It will execute on every server in your cluster
• There is (currently) no error handling
• It could disable your application if your migrations fail