Rollback the whole transaction, even if this is a nested rollback
and reset the nested transaction count to 0.

@return boolean Whether operation was successful.
197169
public function forceRollBack()
    {
        $return = true;

        if ($this->nestedTransactionCount) {
            // If we're in a transaction, always roll it back
            // regardless of nesting level.
            $return = parent::rollBack();

            // reset nested transaction count to 0 so that we don't
            // try to commit (or rollback) the transaction outside this scope.
            $this->nestedTransactionCount = 0;

            if ($this->useDebug) {
                $this->log('Rollback transaction', null, __METHOD__);
            }
        }

        return $return;
    }
887552
public function rollback() {
		if (!$this->inTransaction) {
			return false;
		}

		$this->inTransaction = false;
		return $this->pdo->rollback();
	}
1304136
final public function transRollback()
    {
        $this->logger->info('-- TRANSACTION ROLLBACK ');
        // reduce the transaction level
        if ($this->transactionLevel === 0) {
            trigger_error('Try to call rollback without a transaction', E_USER_NOTICE);
            return;
        }
        $this->transactionLevel = $this->transactionLevel - 1;
        // do rollback or savepoint
        if (0 === $this->transactionLevel) {
            $this->commandTransactionRollback();
        } else {
            $this->commandRollbackToSavepoint("LEVEL_{$this->transactionLevel}");
        }
    }
711155
protected function rollback_transaction() {
        if (!$this->transactions_supported()) {
            return;
        }

        $sql = "ROLLBACK";
        $this->query_start($sql, NULL, SQL_QUERY_AUX);
        $result = $this->mysqli->query($sql);
        $this->query_end($result);

        return true;
    }
85496
public function rollback()
    {
        $res = null;

        if (empty($this->pendingTransactionBegin[$this->transLevel])
            && isset($this->transLevelRolledBack[$this->transLevel])
            && $this->transLevelRolledBack[$this->transLevel] == false
        ) {
            $this->dbRollback();
        }

        if ($this->transLevel == 0) {
            throw $this->createException('Rollback without transaction');
        }

        $this->cleanAfterCommit();
        $this->transLevel--;

        return $this;
    }
502514
protected function rollback()
    {
        $transaction = array_pop($this->_transaction);
        if ($transaction && $transaction instanceof Transaction) {
            $transaction->rollBack();
        }
    }
449757
public function rollBack()
	{
		if ($this->transactions == 1)
		{
			$this->transactions = 0;

			$this->pdo->rollBack();
		}
		else
		{
			--$this->transactions;
		}
	}
73706
public function rollBack() {
        $arg = mysql_query('ROLLBACK', $this->driver);
        $result = empty($arg);
        mysql_query('END', $this->driver);
        return $result;
    }
1047632
public function rollBackTransaction(): bool
	{
		if($this->transactionNestingLevel > 0)
		{
			if($this->transactionNestingLevel > 1)
			{
				$success = $this->rollBackSavepoint();
			}
			else
			{
				$success =  $this->pdo->rollBack();
			}

			$this->transactionNestingLevel--;

			return $success;
		}

		return false;
	}
1208054
public function rollbackTransaction(): bool
    {
        --$this->transactionLevel;

        if ($this->transactionLevel == 0) {
            $this->isProfiling() && $this->getLogger()->info('Rollback transaction');

            try {
                return $this->getPDO()->rollBack();
            } catch (\PDOException $e) {
                throw $this->mapException($e, "ROLLBACK TRANSACTION");
            }
        }

        $this->savepointRollback($this->transactionLevel + 1);

        return true;
    }
652194
public function rollbackTransaction()
    {
        $this->db_connect('w', true);

        // check connection before proceeding
        if (!$this->is_connected()) {
            return $this->last_result = false;
        }

        $this->debug('ROLLBACK TRANSACTION');

        if (@oci_rollback($this->dbh)) {
            $this->in_transaction = false;
        }
        else {
            $this->handle_error('ROLLBACK');
        }

        return $this->last_result = $this->dbh->rollBack();
    }
1149756
public function rollback()
    {
        if ($this->disableTransactionHandling) {
            return;
        }

        if (null === $this->session) {
            throw new RuntimeAdapterException('Transaction not started');
        }
        $this->session->abortTransaction();
        $this->session->endSession();
        $this->session = null;
    }
541877
protected function _trans_rollback()
	{
		if (odbc_rollback($this->conn_id))
		{
			odbc_autocommit($this->conn_id, TRUE);
			return TRUE;
		}

		return FALSE;
	}
1231912
public function rollback()
	{
		if( $this->openTransactions == 0 )
			return false;
		$query = "ROLLBACK";
		$this->Execute( $query );
		$this->openTransactions = 0;
		return true;
	}
69362
protected function rollback_transaction() {
        $this->savepointpresent = false;
        $sql = "RELEASE SAVEPOINT moodle_pg_savepoint; ROLLBACK";
        $this->query_start($sql, null, SQL_QUERY_AUX);
        $result = pg_query($this->pgsql, $sql);
        $this->query_end($result);

        pg_free_result($result);
    }
13323
public function rollBack()
    {
        --$this->currentTransactionLevel;
        if ($this->currentTransactionLevel == 0 || !$this->nestable()) {
            parent::rollBack();
        } else {
            $this->exec("ROLLBACK TO SAVEPOINT LEVEL{$this->currentTransactionLevel}");
        }
    }
1342212
public function rollback()
    {
        if (!empty($this->transactions)) {
            $t = array_pop($this->transactions);
            $this->data = $t['data'];
            $this->lastAI = $t['lastAI'];
        }
        $this->log('ROLLBACK');
    }