<?php
/**
* @package Joomla.Platform
* @subpackage Database
*
* @copyright Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
defined('JPATH_PLATFORM') or die;
/**
* MySQL database driver supporting PDO based connections
*
* @link https://www.php.net/manual/en/ref.pdo-mysql.php
* @since 3.4
*/
class JDatabaseDriverPdomysql extends JDatabaseDriverPdo
{
/**
* The name of the database driver.
*
* @var string
* @since 3.4
*/
public $name = 'pdomysql';
/**
* The type of the database server family supported by this driver.
*
* @var string
* @since CMS 3.5.0
*/
public $serverType = 'mysql';
/**
* The character(s) used to quote SQL statement names such as table names or field names,
* etc. The child classes should define this as necessary. If a single character string the
* same character is used for both sides of the quoted name, else the first character will be
* used for the opening quote and the second for the closing quote.
*
* @var string
* @since 3.4
*/
protected $nameQuote = '`';
/**
* The null or zero representation of a timestamp for the database driver. This should be
* defined in child classes to hold the appropriate value for the engine.
*
* @var string
* @since 3.4
*/
protected $nullDate = '0000-00-00 00:00:00';
/**
* The minimum supported database version.
*
* @var string
* @since 3.4
*/
protected static $dbMinimum = '5.0.4';
/**
* Constructor.
*
* @param array $options Array of database options with keys: host, user, password, database, select.
*
* @since 3.4
*/
public function __construct($options)
{
// Get some basic values from the options.
$options['driver'] = 'mysql';
if (!isset($options['charset']) || $options['charset'] == 'utf8')
{
$options['charset'] = 'utf8mb4';
}
/**
* Pre-populate the UTF-8 Multibyte compatibility flag. Unfortunately PDO won't report the server version
* unless we're connected to it, and we cannot connect to it unless we know if it supports utf8mb4, which requires
* us knowing the server version. Because of this chicken and egg issue, we _assume_ it's supported and we'll just
* catch any problems at connection time.
*/
$this->utf8mb4 = ($options['charset'] == 'utf8mb4');
// Finalize initialisation.
parent::__construct($options);
}
/**
* Connects to the database if needed.
*
* @return void Returns void if the database connected successfully.
*
* @since 3.4
* @throws RuntimeException
*/
public function connect()
{
if ($this->connection)
{
return;
}
try
{
// Try to connect to MySQL
parent::connect();
}
catch (\RuntimeException $e)
{
// If the connection failed, but not because of the wrong character set, then bubble up the exception.
if (!$this->utf8mb4)
{
throw $e;
}
/*
* Otherwise, try connecting again without using
* utf8mb4 and see if maybe that was the problem. If the
* connection succeeds, then we will have learned that the
* client end of the connection does not support utf8mb4.
*/
$this->utf8mb4 = false;
$this->options['charset'] = 'utf8';
parent::connect();
}
if ($this->utf8mb4)
{
/*
* At this point we know the client supports utf8mb4. Now
* we must check if the server supports utf8mb4 as well.
*/
$serverVersion = $this->connection->getAttribute(PDO::ATTR_SERVER_VERSION);
$this->utf8mb4 = version_compare($serverVersion, '5.5.3', '>=');
if (!$this->utf8mb4)
{
// Reconnect with the utf8 character set.
parent::disconnect();
$this->options['charset'] = 'utf8';
parent::connect();
}
}
$this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
// Set sql_mode to non_strict mode
$this->connection->query("SET @@SESSION.sql_mode = '';");
// Disable query cache and turn profiling ON in debug mode.
if ($this->debug)
{
$this->connection->query('SET query_cache_type = 0;');
if ($this->hasProfiling())
{
$this->connection->query('SET profiling_history_size = 100, profiling = 1;');
}
}
}
/**
* Test to see if the MySQL connector is available.
*
* @return boolean True on success, false otherwise.
*
* @since 3.4
*/
public static function isSupported()
{
return class_exists('PDO') && in_array('mysql', PDO::getAvailableDrivers());
}
/**
* Drops a table from the database.
*
* @param string $tableName The name of the database table to drop.
* @param boolean $ifExists Optionally specify that the table must exist before it is dropped.
*
* @return JDatabaseDriverPdomysql Returns this object to support chaining.
*
* @since 3.4
* @throws RuntimeException
*/
public function dropTable($tableName, $ifExists = true)
{
$this->connect();
$query = $this->getQuery(true);
$query->setQuery('DROP TABLE ' . ($ifExists ? 'IF EXISTS ' : '') . $this->quoteName($tableName));
$this->setQuery($query);
$this->execute();
return $this;
}
/**
* Select a database for use.
*
* @param string $database The name of the database to select for use.
*
* @return boolean True if the database was successfully selected.
*
* @since 3.4
* @throws RuntimeException
*/
public function select($database)
{
$this->connect();
$this->setQuery('USE ' . $this->quoteName($database));
$this->execute();
return $this;
}
/**
* Method to get the database collation in use by sampling a text field of a table in the database.
*
* @return mixed The collation in use by the database (string) or boolean false if not supported.
*
* @since 3.4
* @throws RuntimeException
*/
public function getCollation()
{
$this->connect();
// Attempt to get the database collation by accessing the server system variable.
$this->setQuery('SHOW VARIABLES LIKE "collation_database"');
$result = $this->loadObject();
if (property_exists($result, 'Value'))
{
return $result->Value;
}
else
{
return false;
}
}
/**
* Method to get the database connection collation, as reported by the driver. If the connector doesn't support
* reporting this value please return an empty string.
*
* @return string
*/
public function getConnectionCollation()
{
$this->connect();
// Attempt to get the database collation by accessing the server system variable.
$this->setQuery('SHOW VARIABLES LIKE "collation_connection"');
$result = $this->loadObject();
if (property_exists($result, 'Value'))
{
return $result->Value;
}
else
{
return false;
}
}
/**
* Shows the table CREATE statement that creates the given tables.
*
* @param mixed $tables A table name or a list of table names.
*
* @return array A list of the create SQL for the tables.
*
* @since 3.4
* @throws RuntimeException
*/
public function getTableCreate($tables)
{
$this->connect();
// Initialise variables.
$result = array();
// Sanitize input to an array and iterate over the list.
settype($tables, 'array');
foreach ($tables as $table)
{
$this->setQuery('SHOW CREATE TABLE ' . $this->quoteName($table));
$row = $this->loadRow();
// Populate the result array based on the create statements.
$result[$table] = $row[1];
}
return $result;
}
/**
* Retrieves field information about a given table.
*
* @param string $table The name of the database table.
* @param boolean $typeOnly True to only return field types.
*
* @return array An array of fields for the database table.
*
* @since 3.4
* @throws RuntimeException
*/
public function getTableColumns($table, $typeOnly = true)
{
$this->connect();
$result = array();
// Set the query to get the table fields statement.
$this->setQuery('SHOW FULL COLUMNS FROM ' . $this->quoteName($table));
$fields = $this->loadObjectList();
// If we only want the type as the value add just that to the list.
if ($typeOnly)
{
foreach ($fields as $field)
{
$result[$field->Field] = preg_replace('/[(0-9)]/', '', $field->Type);
}
}
// If we want the whole field data object add that to the list.
else
{
foreach ($fields as $field)
{
$result[$field->Field] = $field;
}
}
return $result;
}
/**
* Get the details list of keys for a table.
*
* @param string $table The name of the table.
*
* @return array An array of the column specification for the table.
*
* @since 3.4
* @throws RuntimeException
*/
public function getTableKeys($table)
{
$this->connect();
// Get the details columns information.
$this->setQuery('SHOW KEYS FROM ' . $this->quoteName($table));
$keys = $this->loadObjectList();
return $keys;
}
/**
* Method to get an array of all tables in the database.
*
* @return array An array of all the tables in the database.
*
* @since 3.4
* @throws RuntimeException
*/
public function getTableList()
{
$this->connect();
// Set the query to get the tables statement.
$this->setQuery('SHOW TABLES');
$tables = $this->loadColumn();
return $tables;
}
/**
* Locks a table in the database.
*
* @param string $table The name of the table to unlock.
*
* @return JDatabaseDriverPdomysql Returns this object to support chaining.
*
* @since 3.4
* @throws RuntimeException
*/
public function lockTable($table)
{
$this->setQuery('LOCK TABLES ' . $this->quoteName($table) . ' WRITE')->execute();
return $this;
}
/**
* Renames a table in the database.
*
* @param string $oldTable The name of the table to be renamed
* @param string $newTable The new name for the table.
* @param string $backup Not used by MySQL.
* @param string $prefix Not used by MySQL.
*
* @return JDatabaseDriverPdomysql Returns this object to support chaining.
*
* @since 3.4
* @throws RuntimeException
*/
public function renameTable($oldTable, $newTable, $backup = null, $prefix = null)
{
$this->setQuery('RENAME TABLE ' . $this->quoteName($oldTable) . ' TO ' . $this->quoteName($newTable));
$this->execute();
return $this;
}
/**
* Method to escape a string for usage in an SQL statement.
*
* Oracle escaping reference:
* http://www.orafaq.com/wiki/SQL_FAQ#How_does_one_escape_special_characters_when_writing_SQL_queries.3F
*
* SQLite escaping notes:
* http://www.sqlite.org/faq.html#q14
*
* Method body is as implemented by the Zend Framework
*
* Note: Using query objects with bound variables is
* preferable to the below.
*
* @param string $text The string to be escaped.
* @param boolean $extra Unused optional parameter to provide extra escaping.
*
* @return string The escaped string.
*
* @since 3.4
*/
public function escape($text, $extra = false)
{
if (is_int($text))
{
return $text;
}
if (is_float($text))
{
// Force the dot as a decimal point.
return str_replace(',', '.', $text);
}
$this->connect();
$result = substr($this->connection->quote($text), 1, -1);
if ($extra)
{
$result = addcslashes($result, '%_');
}
return $result;
}
/**
* Unlocks tables in the database.
*
* @return JDatabaseDriverPdomysql Returns this object to support chaining.
*
* @since 3.4
* @throws RuntimeException
*/
public function unlockTables()
{
$this->setQuery('UNLOCK TABLES')->execute();
return $this;
}
/**
* Method to commit a transaction.
*
* @param boolean $toSavepoint If true, commit to the last savepoint.
*
* @return void
*
* @since 3.4
* @throws RuntimeException
*/
public function transactionCommit($toSavepoint = false)
{
$this->connect();
if (!$toSavepoint || $this->transactionDepth <= 1)
{
parent::transactionCommit($toSavepoint);
}
else
{
$this->transactionDepth--;
}
}
/**
* Method to roll back a transaction.
*
* @param boolean $toSavepoint If true, rollback to the last savepoint.
*
* @return void
*
* @since 3.4
* @throws RuntimeException
*/
public function transactionRollback($toSavepoint = false)
{
$this->connect();
if (!$toSavepoint || $this->transactionDepth <= 1)
{
parent::transactionRollback($toSavepoint);
}
else
{
$savepoint = 'SP_' . ($this->transactionDepth - 1);
$this->setQuery('ROLLBACK TO SAVEPOINT ' . $this->quoteName($savepoint));
if ($this->execute())
{
$this->transactionDepth--;
}
}
}
/**
* Method to initialize a transaction.
*
* @param boolean $asSavepoint If true and a transaction is already active, a savepoint will be created.
*
* @return void
*
* @since 3.4
* @throws RuntimeException
*/
public function transactionStart($asSavepoint = false)
{
$this->connect();
if (!$asSavepoint || !$this->transactionDepth)
{
parent::transactionStart($asSavepoint);
}
else
{
$savepoint = 'SP_' . $this->transactionDepth;
$this->setQuery('SAVEPOINT ' . $this->quoteName($savepoint));
if ($this->execute())
{
$this->transactionDepth++;
}
}
}
/**
* Internal function to check if profiling is available.
*
* @return boolean
*
* @since 3.9.1
*/
private function hasProfiling()
{
$result = $this->setQuery("SHOW VARIABLES LIKE 'have_profiling'")->loadAssoc();
return isset($result);
}
}