DbPatch_Command_Abstract::updateColumnType PHP Method

    protected function updateColumnType()
    {
        $adapter = strtolower($this->config->db->adapter);
        if (in_array($adapter, array('mysql', 'mysqli', 'pdo_mysql'))) {
            $columns = $this->getDb()->getAdapter()->describeTable(self::TABLE);
            foreach ($columns as $columnName => $meta) {
                if ($columnName == 'completed' && strtolower($meta['DATA_TYPE']) == 'timestamp') {
                    $db = $this->getDb()->getAdapter();
                    $db->query(sprintf("ALTER TABLE %s ADD completed2 int(11) NOT NULL DEFAULT 0 AFTER completed", $db->quoteIdentifier(self::TABLE)));
                    $db->query(sprintf("UPDATE %s SET completed2 = UNIX_TIMESTAMP(completed)", $db->quoteIdentifier(self::TABLE)));
                    $db->query(sprintf("ALTER TABLE %s DROP COLUMN completed, CHANGE completed2 completed INT(11) NOT NULL", $db->quoteIdentifier(self::TABLE)));
                    $this->writer->line('Updated column type');
                }
            }
        }
    }