lib/private/legacy/db.php
<?php
/**
* @author Andreas Fischer <bantu@owncloud.com>
* @author Bart Visscher <bartv@thisnet.nl>
* @author Joas Schilling <coding@schilljs.com>
* @author Jörn Friedrich Dreyer <jfd@butonic.de>
* @author Morris Jobke <hey@morrisjobke.de>
* @author Robin Appelman <icewind@owncloud.com>
* @author Thomas Müller <thomas.mueller@tmit.eu>
* @author Vincent Petry <pvince81@owncloud.com>
*
* @copyright Copyright (c) 2018, ownCloud GmbH
* @license AGPL-3.0
*
* This code is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License, version 3,
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
/**
* This class manages the access to the database. It basically is a wrapper for
* Doctrine with some adaptions.
*/
class OC_DB {
/**
* get MDB2 schema manager
*
* @return \OC\DB\MDB2SchemaManager
*/
private static function getMDB2SchemaManager() {
return new \OC\DB\MDB2SchemaManager(\OC::$server->getDatabaseConnection());
}
/**
* Prepare a SQL query
* @param string $query Query string
* @param int $limit
* @param int $offset
* @param bool $isManipulation
* @throws \OC\DatabaseException
* @return OC_DB_StatementWrapper prepared SQL query
*
* SQL query via Doctrine prepare(), needs to be execute()'d!
*/
public static function prepare($query, $limit = null, $offset = null, $isManipulation = null) {
$connection = \OC::$server->getDatabaseConnection();
if ($isManipulation === null) {
//try to guess, so we return the number of rows on manipulations
$isManipulation = self::isManipulation($query);
}
// return the result
try {
$result =$connection->prepare($query, $limit, $offset);
} catch (\Doctrine\DBAL\DBALException $e) {
throw new \OC\DatabaseException($e->getMessage(), $query);
}
// differentiate between query and manipulation
$result = new OC_DB_StatementWrapper($result, $isManipulation);
return $result;
}
/**
* tries to guess the type of statement based on the first 10 characters
* the current check allows some whitespace but does not work with IF EXISTS or other more complex statements
*
* @param string $sql
* @return bool
*/
public static function isManipulation($sql) {
$selectOccurrence = \stripos($sql, 'SELECT');
if ($selectOccurrence !== false && $selectOccurrence < 10) {
return false;
}
$insertOccurrence = \stripos($sql, 'INSERT');
if ($insertOccurrence !== false && $insertOccurrence < 10) {
return true;
}
$updateOccurrence = \stripos($sql, 'UPDATE');
if ($updateOccurrence !== false && $updateOccurrence < 10) {
return true;
}
$deleteOccurrence = \stripos($sql, 'DELETE');
if ($deleteOccurrence !== false && $deleteOccurrence < 10) {
return true;
}
return false;
}
/**
* execute a prepared statement, on error write log and throw exception
* @param mixed $stmt OC_DB_StatementWrapper,
* an array with 'sql' and optionally 'limit' and 'offset' keys
* .. or a simple sql query string
* @param array $parameters
* @return OC_DB_StatementWrapper
* @throws \OC\DatabaseException
*/
public static function executeAudited($stmt, array $parameters = null) {
if (\is_string($stmt)) {
// convert to an array with 'sql'
if (\stripos($stmt, 'LIMIT') !== false) { //OFFSET requires LIMIT, so we only need to check for LIMIT
// TODO try to convert LIMIT OFFSET notation to parameters
$message = 'LIMIT and OFFSET are forbidden for portability reasons,'
. ' pass an array with \'limit\' and \'offset\' instead';
throw new \OC\DatabaseException($message);
}
$stmt = ['sql' => $stmt, 'limit' => null, 'offset' => null];
}
if (\is_array($stmt)) {
// convert to prepared statement
if (! \array_key_exists('sql', $stmt)) {
$message = 'statement array must at least contain key \'sql\'';
throw new \OC\DatabaseException($message);
}
if (! \array_key_exists('limit', $stmt)) {
$stmt['limit'] = null;
}
if (! \array_key_exists('limit', $stmt)) {
$stmt['offset'] = null;
}
$stmt = self::prepare($stmt['sql'], $stmt['limit'], $stmt['offset']);
}
self::raiseExceptionOnError($stmt, 'Could not prepare statement');
if ($stmt instanceof OC_DB_StatementWrapper) {
$result = $stmt->execute($parameters === null ? [] : $parameters);
self::raiseExceptionOnError($result, 'Could not execute statement');
} else {
if (\is_object($stmt)) {
$message = 'Expected a prepared statement or array got ' . \get_class($stmt);
} else {
$message = 'Expected a prepared statement or array got ' . \gettype($stmt);
}
throw new \OC\DatabaseException($message);
}
return $result;
}
/**
* saves database schema to xml file
* @param string $file name of file
* @param int $mode
* @return bool
*
* TODO: write more documentation
*/
public static function getDbStructure($file) {
$schemaManager = self::getMDB2SchemaManager();
return $schemaManager->getDbStructure($file);
}
/**
* Creates tables from XML file
* @param string $file file to read structure from
* @return bool
*
* TODO: write more documentation
*/
public static function createDbFromStructure($file) {
$schemaManager = self::getMDB2SchemaManager();
$result = $schemaManager->createDbFromStructure($file);
return $result;
}
/**
* update the database schema
* @param string $file file to read structure from
* @throws Exception
* @return string|boolean
*/
public static function updateDbFromStructure($file) {
$schemaManager = self::getMDB2SchemaManager();
try {
$result = $schemaManager->updateDbFromStructure($file);
} catch (Exception $e) {
\OCP\Util::writeLog('core', 'Failed to update database structure ('.$e.')', \OCP\Util::FATAL);
throw $e;
}
return $result;
}
/**
* remove all tables defined in a database structure xml file
* @param string $file the xml file describing the tables
*/
public static function removeDBStructure($file) {
$schemaManager = self::getMDB2SchemaManager();
$schemaManager->removeDBStructure($file);
}
/**
* check if a result is an error and throws an exception, works with \Doctrine\DBAL\DBALException
* @param mixed $result
* @param string $message
* @return void
* @throws \OC\DatabaseException
*/
public static function raiseExceptionOnError($result, $message = null) {
if ($result === false) {
if ($message === null) {
$message = self::getErrorMessage();
} else {
$message .= ', Root cause:' . self::getErrorMessage();
}
throw new \OC\DatabaseException($message, \OC::$server->getDatabaseConnection()->errorCode());
}
}
/**
* returns the error code and message as a string for logging
* works with DoctrineException
* @return string
*/
public static function getErrorMessage() {
$connection = \OC::$server->getDatabaseConnection();
return $connection->getError();
}
/**
* Checks if a table exists in the database - the database prefix will be prepended
*
* @param string $table
* @return bool
* @throws \OC\DatabaseException
*/
public static function tableExists($table) {
$connection = \OC::$server->getDatabaseConnection();
return $connection->tableExists($table);
}
}