+ $this->addSql('ALTER DATABASE ' . $this->connection->getParams()['dbname'] . ' CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;');
+
+ // convert field length for utf8mb4
+ // http://stackoverflow.com/a/31474509/569101
+ $this->addSql('ALTER TABLE ' . $this->getTable('user') . ' CHANGE confirmation_token confirmation_token VARCHAR(180) DEFAULT NULL;');
+ $this->addSql('ALTER TABLE ' . $this->getTable('user') . ' CHANGE salt salt VARCHAR(180) NOT NULL;');
+ $this->addSql('ALTER TABLE ' . $this->getTable('user') . ' CHANGE password password VARCHAR(180) NOT NULL;');