Piwik\Updater::executeMigration PHP Method

    public function executeMigration($file, Migration $migration)
    {
        try {
            $this->executeListenerHook('onStartExecutingMigration', array($file, $migration));
            $migration->exec();
        } catch (\Exception $e) {
            if (!$migration->shouldIgnoreError($e)) {
                $message = sprintf("%s:\nError trying to execute the migration '%s'.\nThe error was: %s", $file, $migration->__toString(), $e->getMessage());
                throw new UpdaterErrorException($message);
            }
        }
        $this->executeListenerHook('onFinishedExecutingMigration', array($file, $migration));
    }

 public function doUpdate(Updater $updater)
 {
     $returningMetrics = array('nb_visits_returning', 'nb_actions_returning', 'max_actions_returning', 'sum_visit_length_returning', 'bounce_count_returning', 'nb_visits_converted_returning', 'nb_uniq_visitors_returning');
     $now = Date::factory('now')->getDatetime();
     $archiveNumericTables = Db::get()->fetchCol("SHOW TABLES LIKE '%archive_numeric%'");
     // for each numeric archive table, copy *_returning metrics to VisitsSummary metrics w/ the appropriate
     // returning visit segment
     foreach ($archiveNumericTables as $table) {
         // get archives w/ *._returning
         $sql = "SELECT idarchive, idsite, period, date1, date2 FROM {$table}\n                    WHERE name IN ('" . implode("','", $returningMetrics) . "')\n                    GROUP BY idarchive";
         $idArchivesWithReturning = Db::fetchAll($sql);
         // get archives for visitssummary returning visitor segment
         $sql = "SELECT idarchive, idsite, period, date1, date2 FROM {$table}\n                    WHERE name = ?  GROUP BY idarchive";
         $visitSummaryReturningSegmentDone = Rules::getDoneFlagArchiveContainsOnePlugin(new Segment(VisitFrequencyApi::RETURNING_VISITOR_SEGMENT, $idSites = array()), 'VisitsSummary');
         $idArchivesWithVisitReturningSegment = Db::fetchAll($sql, array($visitSummaryReturningSegmentDone));
         // collect info for new visitssummary archives have to be created to match archives w/ *._returning
         // metrics
         $missingIdArchives = array();
         $idArchiveMappings = array();
         foreach ($idArchivesWithReturning as $row) {
             $withMetricsIdArchive = $row['idarchive'];
             foreach ($idArchivesWithVisitReturningSegment as $segmentRow) {
                 if ($row['idsite'] == $segmentRow['idsite'] && $row['period'] == $segmentRow['period'] && $row['date1'] == $segmentRow['date1'] && $row['date2'] == $segmentRow['date2']) {
                     $idArchiveMappings[$withMetricsIdArchive] = $segmentRow['idarchive'];
                 }
             }
             if (!isset($idArchiveMappings[$withMetricsIdArchive])) {
                 $missingIdArchives[$withMetricsIdArchive] = $row;
             }
         }
         // if there are missing idarchives, fill out new archive row values
         if (!empty($missingIdArchives)) {
             $newIdArchiveStart = Db::fetchOne("SELECT MAX(idarchive) FROM {$table}") + 1;
             foreach ($missingIdArchives as $withMetricsIdArchive => &$rowToInsert) {
                 $idArchiveMappings[$withMetricsIdArchive] = $newIdArchiveStart;
                 $rowToInsert['idarchive'] = $newIdArchiveStart;
                 $rowToInsert['ts_archived'] = $now;
                 $rowToInsert['name'] = $visitSummaryReturningSegmentDone;
                 $rowToInsert['value'] = ArchiveWriter::DONE_OK;
                 ++$newIdArchiveStart;
             }
             // add missing archives
             $params = array();
             foreach ($missingIdArchives as $missingIdArchive) {
                 $params[] = array_values($missingIdArchive);
             }
             $fields = array_keys(reset($missingIdArchives));
             $tableUnprefixed = Common::unprefixTable($table);
             $migration = $this->migration->db->batchInsert($tableUnprefixed, $fields, $params, $throwException = false, $charset = 'latin1');
             $updater->executeMigration(__FILE__, $migration);
         }
         // update idarchive & name columns in rows with *._returning metrics
         $updateSqlPrefix = "UPDATE {$table}\n                                   SET idarchive = CASE idarchive ";
         $updateSqlSuffix = " END, name = CASE name ";
         foreach ($returningMetrics as $metric) {
             $newMetricName = substr($metric, 0, strlen($metric) - strlen(VisitFrequencyApi::COLUMN_SUFFIX));
             $updateSqlSuffix .= "WHEN '{$metric}' THEN '" . $newMetricName . "' ";
         }
         $updateSqlSuffix .= " END WHERE idarchive IN (%s)\n                                        AND name IN ('" . implode("','", $returningMetrics) . "')";
         // update only 1000 rows at a time so we don't send too large an SQL query to MySQL
         foreach (array_chunk($missingIdArchives, 1000, $preserveKeys = true) as $chunk) {
             $idArchives = array();
             $updateSql = $updateSqlPrefix;
             foreach ($chunk as $withMetricsIdArchive => $row) {
                 $updateSql .= "WHEN {$withMetricsIdArchive} THEN {$row['idarchive']} ";
                 $idArchives[] = $withMetricsIdArchive;
             }
             $updateSql .= sprintf($updateSqlSuffix, implode(',', $idArchives));
             $updater->executeMigration(__FILE__, $this->migration->db->sql($updateSql));
         }
     }
 }