owncloud/core

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lib/public/AppFramework/Db/Mapper.php

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<?php
/**
 * @author Bernhard Posselt <dev@bernhard-posselt.com>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 *
 * @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/>
 *
 */

namespace OCP\AppFramework\Db;

use OCP\DB\QueryBuilder\IQueryBuilder;
use OCP\IDBConnection;
use OCP\IDb;

/**
 * Simple parent class for inheriting your data access layer from. This class
 * may be subject to change in the future
 * @since 7.0.0
 */
abstract class Mapper {
    protected $tableName;
    protected $entityClass;
    protected $db;

    /**
     * @param IDBConnection $db Instance of the Db abstraction layer
     * @param string $tableName the name of the table. set this to allow entity
     * @param string $entityClass the name of the entity that the sql should be
     * mapped to queries without using sql
     * @since 7.0.0
     */
    public function __construct(IDBConnection $db, $tableName, $entityClass=null) {
        $this->db = $db;
        $this->tableName = '*PREFIX*' . $tableName;

        // if not given set the entity name to the class without the mapper part
        // cache it here for later use since reflection is slow
        if ($entityClass === null) {
            $this->entityClass = \str_replace('Mapper', '', \get_class($this));
        } else {
            $this->entityClass = $entityClass;
        }
    }

    /**
     * @return string the table name
     * @since 7.0.0
     */
    public function getTableName() {
        return $this->tableName;
    }

    /**
     * Deletes an entity from the table
     * @param Entity $entity the entity that should be deleted
     * @return Entity the deleted entity
     * @since 7.0.0 - return value added in 8.1.0
     */
    public function delete(Entity $entity) {
        $sql = 'DELETE FROM `' . $this->tableName . '` WHERE `id` = ?';
        $stmt = $this->execute($sql, [$entity->getId()]);
        $stmt->closeCursor();
        return $entity;
    }

    /**
     * Creates a new entry in the db from an entity
     * @param Entity $entity the entity that should be created
     * @return Entity the saved entity with the set id
     * @since 7.0.0
     */
    public function insert(Entity $entity) {
        // get updated fields to save, fields have to be set using a setter to
        // be saved
        $properties = $entity->getUpdatedFields();
        $values = '';
        $columns = '';
        $params = [];

        // build the fields
        $i = 0;
        foreach ($properties as $property => $updated) {
            $column = $entity->propertyToColumn($property);
            $getter = 'get' . \ucfirst($property);

            $columns .= '`' . $column . '`';
            $values .= '?';

            // only append colon if there are more entries
            if ($i < \count($properties)-1) {
                $columns .= ',';
                $values .= ',';
            }

            $params[] = $entity->$getter();
            $i++;
        }

        $sql = 'INSERT INTO `' . $this->tableName . '`(' .
                $columns . ') VALUES(' . $values . ')';

        $stmt = $this->execute($sql, $params);

        $entity->setId((int) $this->db->lastInsertId($this->tableName));

        $stmt->closeCursor();

        return $entity;
    }

    /**
     * Updates an entry in the db from an entity
     * @throws \InvalidArgumentException if entity has no id
     * @param Entity $entity the entity that should be created
     * @return Entity the saved entity with the set id
     * @since 7.0.0 - return value was added in 8.0.0
     */
    public function update(Entity $entity) {
        // if entity wasn't changed it makes no sense to run a db query
        $properties = $entity->getUpdatedFields();
        if (\count($properties) === 0) {
            return $entity;
        }

        // entity needs an id
        $id = $entity->getId();
        if ($id === null) {
            throw new \InvalidArgumentException(
                'Entity which should be updated has no id'
            );
        }

        // get updated fields to save, fields have to be set using a setter to
        // be saved
        // do not update the id field
        unset($properties['id']);

        $columns = '';
        $params = [];

        // build the fields
        $i = 0;
        foreach ($properties as $property => $updated) {
            $column = $entity->propertyToColumn($property);
            $getter = 'get' . \ucfirst($property);

            $columns .= '`' . $column . '` = ?';

            // only append colon if there are more entries
            if ($i < \count($properties)-1) {
                $columns .= ',';
            }

            $params[] = $entity->$getter();
            $i++;
        }

        $sql = 'UPDATE `' . $this->tableName . '` SET ' .
                $columns . ' WHERE `id` = ?';
        $params[] = $id;

        $stmt = $this->execute($sql, $params);
        $stmt->closeCursor();

        return $entity;
    }

    /**
     * Checks if an array is associative
     * @param array $array
     * @return bool true if associative
     * @since 8.1.0
     */
    private function isAssocArray(array $array) {
        return \array_values($array) !== $array;
    }

    /**
     * Returns the correct PDO constant based on the value type
     * @param $value
     * @return int PDO constant
     * @since 8.1.0
     */
    private function getPDOType($value) {
        switch (\gettype($value)) {
            case 'integer':
                return \PDO::PARAM_INT;
            case 'boolean':
                return \PDO::PARAM_BOOL;
            default:
                return \PDO::PARAM_STR;
        }
    }

    /**
     * Runs an sql query
     * @param string $sql the prepare string
     * @param array $params the params which should replace the ? in the sql query
     * @param int $limit the maximum number of rows
     * @param int $offset from which row we want to start
     * @return \PDOStatement the database query result
     * @since 7.0.0
     */
    protected function execute($sql, array $params=[], $limit=null, $offset=null) {
        if ($this->db instanceof IDb) {
            $query = $this->db->prepareQuery($sql, $limit, $offset);
        } else {
            $query = $this->db->prepare($sql, $limit, $offset);
        }

        if ($this->isAssocArray($params)) {
            foreach ($params as $key => $param) {
                $pdoConstant = $this->getPDOType($param);
                $query->bindValue($key, $param, $pdoConstant);
            }
        } else {
            $index = 1;  // bindParam is 1 indexed
            foreach ($params as $param) {
                $pdoConstant = $this->getPDOType($param);
                $query->bindValue($index, $param, $pdoConstant);
                $index++;
            }
        }

        $result = $query->execute();

        // this is only for backwards compatibility reasons and can be removed
        // in owncloud 10. IDb returns a StatementWrapper from execute, PDO,
        // Doctrine and IDbConnection don't so this needs to be done in order
        // to stay backwards compatible for the things that rely on the
        // StatementWrapper being returned
        if ($result instanceof \OC_DB_StatementWrapper) {
            return $result;
        }

        return $query;
    }

    /**
     * Returns an db result and throws exceptions when there are more or less
     * results
     * @see findEntity
     * @param string $sql the sql query
     * @param array $params the parameters of the sql query
     * @param int $limit the maximum number of rows
     * @param int $offset from which row we want to start
     * @throws DoesNotExistException if the item does not exist
     * @throws MultipleObjectsReturnedException if more than one item exist
     * @return array the result as row
     * @since 7.0.0
     */
    protected function findOneQuery($sql, array $params=[], $limit=null, $offset=null) {
        if ($sql instanceof IQueryBuilder) {
            $stmt = $sql->execute();
        } else {
            $stmt = $this->execute($sql, $params, $limit, $offset);
        }
        $row = $stmt->fetch();

        if ($row === false || $row === null) {
            $stmt->closeCursor();
            $msg = $this->buildDebugMessage(
                'Did expect one result but found none when executing',
                $sql,
                $params,
                $limit,
                $offset
            );
            throw new DoesNotExistException($msg);
        }
        $row2 = $stmt->fetch();
        $stmt->closeCursor();
        //MDB2 returns null, PDO and doctrine false when no row is available
        if (! ($row2 === false || $row2 === null)) {
            $msg = $this->buildDebugMessage(
                'Did not expect more than one result when executing',
                $sql,
                $params,
                $limit,
                $offset
            );
            throw new MultipleObjectsReturnedException($msg);
        } else {
            return $row;
        }
    }

    /**
     * Builds an error message by prepending the $msg to an error message which
     * has the parameters
     * @see findEntity
     * @param string $sql the sql query
     * @param array $params the parameters of the sql query
     * @param int $limit the maximum number of rows
     * @param int $offset from which row we want to start
     * @return string formatted error message string
     * @since 9.1.0
     */
    private function buildDebugMessage($msg, $sql, array $params=[], $limit=null, $offset=null) {
        return $msg .
                    ': query "' .    $sql . '"; ' .
                    'parameters ' . \print_r($params, true) . '; ' .
                    'limit "' . $limit . '"; '.
                    'offset "' . $offset . '"';
    }

    /**
     * Creates an entity from a row. Automatically determines the entity class
     * from the current mapper name (MyEntityMapper -> MyEntity)
     * @param array $row the row which should be converted to an entity
     * @return Entity the entity
     * @since 7.0.0
     */
    protected function mapRowToEntity($row) {
        unset($row['DOCTRINE_ROWNUM']); // Remove oracle workaround for limit
        return \call_user_func($this->entityClass .'::fromRow', $row);
    }

    /**
     * Runs a sql query and returns an array of entities
     * @param string $sql the prepare string
     * @param array $params the params which should replace the ? in the sql query
     * @param int $limit the maximum number of rows
     * @param int $offset from which row we want to start
     * @return array all fetched entities
     * @since 7.0.0
     */
    protected function findEntities($sql, array $params=[], $limit=null, $offset=null) {
        $stmt = $this->execute($sql, $params, $limit, $offset);

        $entities = [];

        while ($row = $stmt->fetch()) {
            $entities[] = $this->mapRowToEntity($row);
        }

        $stmt->closeCursor();

        return $entities;
    }

    /**
     * Returns an db result and throws exceptions when there are more or less
     * results
     * @param string $sql the sql query
     * @param array $params the parameters of the sql query
     * @param int $limit the maximum number of rows
     * @param int $offset from which row we want to start
     * @throws DoesNotExistException if the item does not exist
     * @throws MultipleObjectsReturnedException if more than one item exist
     * @return Entity the entity
     * @since 7.0.0
     */
    protected function findEntity($sql, array $params=[], $limit=null, $offset=null) {
        return $this->mapRowToEntity($this->findOneQuery($sql, $params, $limit, $offset));
    }
}