FuelPHP v1 Migration Examples/Suggestions

001_db_stuff.php

<?php

namespace Fuel\Migrations;

class Db_Stuff
{

	public function up()
	{
		// Try/catch so that we can provide a nicer error message and gracefully fall out of the migration
		try {
			// If your migration has a dependency on another package/module's migrations then you can make sure that package/module has been migrated like this
			// In this example this migration relies on a module within the propshop package so we need to make sure that the appropriate module path is available
			\Config::set('module_paths.99999', PKGPATH.'/propshop/modules/');
 
			// This example depends on migration number 5 of the shipping module so we will run that module up to that point
			$results = \Migrate::up(5, 'shipping', 'module');
 
			// If things were successful then we will get an array of the migrations that were run
			if (! is_array($results)) {
				// Report that one of the dependencies failed and return false
				\Cli::error('Could not migrate dependencies: ' . __FILE__);
				return false;
			}

			// Always wrap all DB calls in a transaction
			// Data definition language (DDL) statements are not compatible with transactions
			// However, transactions should always be used for consistency, people just need to be aware of their limits
			\DB::start_transaction();
			
			\DBUtil::create_table(...);
			\DB::insert(...);
			
			\DB::commit_transaction();

		} catch (\Exception $e) {

			\DB::rollback_transaction();

			\Cli::error(sprintf('Up Migration Failed - %s - %s', $e->getMessage(), __FILE__));
			return false;

		}
		
		\Cli::write('Migrated Up Successfully: ' . __FILE__, 'green');
	}
	
	public function down()
	{
		try {

			\DB::start_transaction();
			
			// The down of a migration should undo any changes made by the up
			// It is neccessary to remove foreign keys/constraints, remove added data, 
			// manipulate data in reverse, remove added fields, drop created tables
			// This is not an exaustive list
			\DB::delete(...);
			\DBUtil::drop_table(...);
			
			\DB::commit_transaction();

		} catch (\Exception $e) {

			\DB::rollback_transaction();

			\Cli::error(sprintf('Down Migration Failed - %s - %s', $e->getMessage(), __FILE__));
			return false;

		}
		
		\Cli::write('Migrated Down Successfully: ' . __FILE__, 'green');
	}
	
}

002_do_something.php

<?php

namespace Fuel\Migrations;

class Do_Something
{

	public function up()
	{
		// Try/catch so that we can provide a nicer error message and gracefully fall out of the migration
		try {

			// You don't always have to do DB stuff in migrations, examples of other things that might
			// be done in a migration are, creating folder structure, moving/copying files, running a task

		} catch (\Exception $e) {

			\Cli::error(sprintf('Up Migration Failed - %s - %s', $e->getMessage(), __FILE__));
			return false;

		}
		
		\Cli::write('Migrated Up Successfully: ' . __FILE__, 'green');
	}
	
	public function down()
	{
		try {

			// Sometimes migrations can't be undone, e.g. one that runs a task
			// However, every effort should be made to get things back to the state things were in
			// before the up was run, and at the very least allow for the up to be re-run successfully

		} catch (\Exception $e) {

			\Cli::error(sprintf('Down Migration Failed - %s - %s', $e->getMessage(), __FILE__));
			return false;

		}
		
		\Cli::write('Migrated Down Successfully: ' . __FILE__, 'green');
	}
	
}