silverstripe-contentreview/code/tasks/ContentReviewOwnerMigrationTask.php

<?php
/**
 * Task which migrates the ContentReview Module's SiteTree->OwnerID column to a new column name
 */
class ContentReviewOwnerMigrationTask extends BuildTask {
	
	/**
	 * 
	 * @param SS_HTTPRequest $request
	 */
	public function run($request) {
		$results = DB::query('SHOW columns from "SiteTree" WHERE "field" = \'OwnerID\'');
		if ($results->numRecords() == 0) {
			echo "<h1>No need to run task. SiteTree->OwnerID doesn't exist</h1>";
		} else {
			DB::query('UPDATE "SiteTree" SET "ContentReviewOwnerID" = "OwnerID"');
			DB::query('UPDATE "SiteTree_Live" SET "ContentReviewOwnerID" = "OwnerID"');
			DB::query('UPDATE "SiteTree_versions" SET "ContentReviewOwnerID" = "OwnerID"');
			DB::query('ALTER TABLE "SiteTree" DROP COLUMN "OwnerID"');
			DB::query('ALTER TABLE "SiteTree_Live" DROP COLUMN "OwnerID"');
			DB::query('ALTER TABLE "SiteTree_versions" DROP COLUMN "OwnerID"');
			echo "<h1>Migrated 3 tables. Dropped obsolete OwnerID column</h1>";
		}
	}
}