Aspen Framework

From Aspen Documentation

Aspen has a system that will allow you to automate database upgrades of a distributed application.

First, your application must have a build number present in the config files called application_build. If this build is higher than the latest build number present in the upgrade_history table (automatically added with each upgrade) then Aspen tries to find if there are any SQL changes to apply.

Inside of the modules/Install/sql/upgrade.sql file, you may place a query into an array with the build revision that the query must be applied to.

For example:

 $sql['1022'][] = "DROP TABLE 'oldtable'";

If the latest build stored in the upgrade_history table is 1000 and the build number present in the latest code is 1040 the any queries with a build number (key in the array) between those number will be executed.

Upon success, the new build number will be stored in the database.

Note: This system works only for your application tables, and will not work properly if changing tables required for aspen to function. A new version of aspen that requires a specific field may not function without such a field, hence it will be unable to run the upgrade.