<?php
/**
* @file
* Database interface code for MySQL database servers.
*/
/**
* The default character for quoting identifiers in MySQL.
*/
define('MYSQL_IDENTIFIER_QUOTE_CHARACTER_DEFAULT', '`');
/**
* @addtogroup database
* @{
*/
class DatabaseConnection_mysql extends DatabaseConnection {
/**
* Flag to indicate if the cleanup function in __destruct() should run.
*
* @var boolean
*/
protected $needsCleanup = FALSE;
/**
* The list of MySQL reserved key words.
*
* @link https://dev.mysql.com/doc/refman/8.0/en/keywords.html
*/
private $reservedKeyWords = array(
'accessible',
'add',
'admin',
'all',
'alter',
'analyze',
'and',
'as',
'asc',
'asensitive',
'before',
'between',
'bigint',
'binary',
'blob',
'both',
'by',
'call',
'cascade',
'case',
'change',
'char',
'character',
'check',
'collate',
'column',
'condition',
'constraint',
'continue',
'convert',
'create',
'cross',
'cube',
'cume_dist',
'current_date',
'current_time',
'current_timestamp',
'current_user',
'cursor',
'database',
'databases',
'day_hour',
'day_microsecond',
'day_minute',
'day_second',
'dec',
'decimal',
'declare',
'default',
'delayed',
'delete',
'dense_rank',
'desc',
'describe',
'deterministic',
'distinct',
'distinctrow',
'div',
'double',
'drop',
'dual',
'each',
'else',
'elseif',
'empty',
'enclosed',
'escaped',
'except',
'exists',
'exit',
'explain',
'false',
'fetch',
'first_value',
'float',
'float4',
'float8',
'for',
'force',
'foreign',
'from',
'fulltext',
'function',
'generated',
'get',
'grant',
'group',
'grouping',
'groups',
'having',
'high_priority',
'hour_microsecond',
'hour_minute',
'hour_second',
'if',
'ignore',
'in',
'index',
'infile',
'inner',
'inout',
'insensitive',
'insert',
'int',
'int1',
'int2',
'int3',
'int4',
'int8',
'integer',
'interval',
'into',
'io_after_gtids',
'io_before_gtids',
'is',
'iterate',
'join',
'json_table',
'key',
'keys',
'kill',
'lag',
'last_value',
'lead',
'leading',
'leave',
'left',
'like',
'limit',
'linear',
'lines',
'load',
'localtime',
'localtimestamp',
'lock',
'long',
'longblob',
'longtext',
'loop',
'low_priority',
'master_bind',
'master_ssl_verify_server_cert',
'match',
'maxvalue',
'mediumblob',
'mediumint',
'mediumtext',
'middleint',
'minute_microsecond',
'minute_second',
'mod',
'modifies',
'natural',
'not',
'no_write_to_binlog',
'nth_value',
'ntile',
'null',
'numeric',
'of',
'on',
'optimize',
'optimizer_costs',
'option',
'optionally',
'or',
'order',
'out',
'outer',
'outfile',
'over',
'partition',
'percent_rank',
'persist',
'persist_only',
'precision',
'primary',
'procedure',
'purge',
'range',
'rank',
'read',
'reads',
'read_write',
'real',
'recursive',
'references',
'regexp',
'release',
'rename',
'repeat',
'replace',
'require',
'resignal',
'restrict',
'return',
'revoke',
'right',
'rlike',
'row',
'rows',
'row_number',
'schema',
'schemas',
'second_microsecond',
'select',
'sensitive',
'separator',
'set',
'show',
'signal',
'smallint',
'spatial',
'specific',
'sql',
'sqlexception',
'sqlstate',
'sqlwarning',
'sql_big_result',
'sql_calc_found_rows',
'sql_small_result',
'ssl',
'starting',
'stored',
'straight_join',
'system',
'table',
'terminated',
'then',
'tinyblob',
'tinyint',
'tinytext',
'to',
'trailing',
'trigger',
'true',
'undo',
'union',
'unique',
'unlock',
'unsigned',
'update',
'usage',
'use',
'using',
'utc_date',
'utc_time',
'utc_timestamp',
'values',
'varbinary',
'varchar',
'varcharacter',
'varying',
'virtual',
'when',
'where',
'while',
'window',
'with',
'write',
'xor',
'year_month',
'zerofill',
);
public function __construct(array $connection_options = array()) {
// This driver defaults to transaction support, except if explicitly passed FALSE.
$this->transactionSupport = !isset($connection_options['transactions']) || ($connection_options['transactions'] !== FALSE);
// MySQL never supports transactional DDL.
$this->transactionalDDLSupport = FALSE;
$this->connectionOptions = $connection_options;
$charset = 'utf8';
// Check if the charset is overridden to utf8mb4 in settings.php.
if ($this->utf8mb4IsActive()) {
$charset = 'utf8mb4';
}
// The DSN should use either a socket or a host/port.
if (isset($connection_options['unix_socket'])) {
$dsn = 'mysql:unix_socket=' . $connection_options['unix_socket'];
}
else {
// Default to TCP connection on port 3306.
$dsn = 'mysql:host=' . $connection_options['host'] . ';port=' . (empty($connection_options['port']) ? 3306 : $connection_options['port']);
}
// Character set is added to dsn to ensure PDO uses the proper character
// set when escaping. This has security implications. See
// https://www.drupal.org/node/1201452 for further discussion.
$dsn .= ';charset=' . $charset;
$dsn .= ';dbname=' . $connection_options['database'];
// Allow PDO options to be overridden.
$connection_options += array(
'pdo' => array(),
);
$connection_options['pdo'] += array(
// So we don't have to mess around with cursors and unbuffered queries by default.
PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE,
// Because MySQL's prepared statements skip the query cache, because it's dumb.
PDO::ATTR_EMULATE_PREPARES => TRUE,
// Convert numeric values to strings when fetching. In PHP 8.1,
// PDO::ATTR_EMULATE_PREPARES now behaves the same way as non emulated
// prepares and returns integers. See https://externals.io/message/113294
// for further discussion.
PDO::ATTR_STRINGIFY_FETCHES => TRUE,
);
if (defined('PDO::MYSQL_ATTR_MULTI_STATEMENTS')) {
// An added connection option in PHP 5.5.21+ to optionally limit SQL to a
// single statement like mysqli.
$connection_options['pdo'] += array(PDO::MYSQL_ATTR_MULTI_STATEMENTS => FALSE);
}
parent::__construct($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
// Force MySQL to use the UTF-8 character set. Also set the collation, if a
// certain one has been set; otherwise, MySQL defaults to 'utf8_general_ci'
// for UTF-8.
if (!empty($connection_options['collation'])) {
$this->connection->exec('SET NAMES ' . $charset . ' COLLATE ' . $connection_options['collation']);
}
else {
$this->connection->exec('SET NAMES ' . $charset);
}
// Set MySQL init_commands if not already defined. Default Drupal's MySQL
// behavior to conform more closely to SQL standards. This allows Drupal
// to run almost seamlessly on many different kinds of database systems.
// These settings force MySQL to behave the same as postgresql, or sqlite
// in regards to syntax interpretation and invalid data handling. See
// http://drupal.org/node/344575 for further discussion. Also, as MySQL 5.5
// changed the meaning of TRADITIONAL we need to spell out the modes one by
// one.
$connection_options += array(
'init_commands' => array(),
);
$sql_mode = 'REAL_AS_FLOAT,PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO';
// NO_AUTO_CREATE_USER was removed in MySQL 8.0.11
// https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-11.html#mysqld-8-0-11-deprecation-removal
if (version_compare($this->connection->getAttribute(PDO::ATTR_SERVER_VERSION), '8.0.11', '<')) {
$sql_mode .= ',NO_AUTO_CREATE_USER';
}
$connection_options['init_commands'] += array(
'sql_mode' => "SET sql_mode = '$sql_mode'",
);
// Execute initial commands.
foreach ($connection_options['init_commands'] as $sql) {
$this->connection->exec($sql);
}
}
/**
* {@inheritdoc}}
*/
protected function setPrefix($prefix) {
parent::setPrefix($prefix);
// Successive versions of MySQL have become increasingly strict about the
// use of reserved keywords as table names. Drupal 7 uses at least one such
// table (system). Therefore we surround all table names with quotes.
$quote_char = variable_get('mysql_identifier_quote_character', MYSQL_IDENTIFIER_QUOTE_CHARACTER_DEFAULT);
foreach ($this->prefixSearch as $i => $prefixSearch) {
if (substr($prefixSearch, 0, 1) === '{') {
// If the prefix already contains one or more quotes remove them.
// This can happen when - for example - DrupalUnitTestCase sets up a
// "temporary prefixed database". Also if there's a dot in the prefix,
// wrap it in quotes to cater for schema names in prefixes.
$search = array($quote_char, '.');
$replace = array('', $quote_char . '.' . $quote_char);
$this->prefixReplace[$i] = $quote_char . str_replace($search, $replace, $this->prefixReplace[$i]);
}
if (substr($prefixSearch, -1) === '}') {
$this->prefixReplace[$i] .= $quote_char;
}
}
}
/**
* {@inheritdoc}
*/
public function escapeField($field) {
$field = parent::escapeField($field);
return $this->quoteIdentifier($field);
}
public function escapeFields(array $fields) {
foreach ($fields as &$field) {
$field = $this->escapeField($field);
}
return $fields;
}
/**
* {@inheritdoc}
*/
public function escapeAlias($field) {
$field = parent::escapeAlias($field);
return $this->quoteIdentifier($field);
}
/**
* Quotes an identifier if it matches a MySQL reserved keyword.
*
* @param string $identifier
* The field to check.
*
* @return string
* The identifier, quoted if it matches a MySQL reserved keyword.
*/
private function quoteIdentifier($identifier) {
// Quote identifiers so that MySQL reserved words like 'function' can be
// used as column names. Sometimes the 'table.column_name' format is passed
// in. For example, menu_load_links() adds a condition on "ml.menu_name".
if (strpos($identifier, '.') !== FALSE) {
list($table, $identifier) = explode('.', $identifier, 2);
}
if (in_array(strtolower($identifier), $this->reservedKeyWords, TRUE)) {
// Quote the string for MySQL reserved keywords.
$quote_char = variable_get('mysql_identifier_quote_character', MYSQL_IDENTIFIER_QUOTE_CHARACTER_DEFAULT);
$identifier = $quote_char . $identifier . $quote_char;
}
return isset($table) ? $table . '.' . $identifier : $identifier;
}
public function __destruct() {
if ($this->needsCleanup) {
$this->nextIdDelete();
}
}
public function queryRange($query, $from, $count, array $args = array(), array $options = array()) {
return $this->query($query . ' LIMIT ' . (int) $from . ', ' . (int) $count, $args, $options);
}
public function queryTemporary($query, array $args = array(), array $options = array()) {
$tablename = $this->generateTemporaryTableName();
$this->query('CREATE TEMPORARY TABLE {' . $tablename . '} Engine=MEMORY ' . $query, $args, $options);
return $tablename;
}
public function driver() {
return 'mysql';
}
public function databaseType() {
return 'mysql';
}
public function mapConditionOperator($operator) {
// We don't want to override any of the defaults.
return NULL;
}
public function nextId($existing_id = 0) {
$new_id = $this->query('INSERT INTO {sequences} () VALUES ()', array(), array('return' => Database::RETURN_INSERT_ID));
// This should only happen after an import or similar event.
if ($existing_id >= $new_id) {
// If we INSERT a value manually into the sequences table, on the next
// INSERT, MySQL will generate a larger value. However, there is no way
// of knowing whether this value already exists in the table. MySQL
// provides an INSERT IGNORE which would work, but that can mask problems
// other than duplicate keys. Instead, we use INSERT ... ON DUPLICATE KEY
// UPDATE in such a way that the UPDATE does not do anything. This way,
// duplicate keys do not generate errors but everything else does.
$this->query('INSERT INTO {sequences} (value) VALUES (:value) ON DUPLICATE KEY UPDATE value = value', array(':value' => $existing_id));
$new_id = $this->query('INSERT INTO {sequences} () VALUES ()', array(), array('return' => Database::RETURN_INSERT_ID));
}
$this->needsCleanup = TRUE;
return $new_id;
}
public function nextIdDelete() {
// While we want to clean up the table to keep it up from occupying too
// much storage and memory, we must keep the highest value in the table
// because InnoDB uses an in-memory auto-increment counter as long as the
// server runs. When the server is stopped and restarted, InnoDB
// reinitializes the counter for each table for the first INSERT to the
// table based solely on values from the table so deleting all values would
// be a problem in this case. Also, TRUNCATE resets the auto increment
// counter.
try {
$max_id = $this->query('SELECT MAX(value) FROM {sequences}')->fetchField();
// We know we are using MySQL here, no need for the slower db_delete().
$this->query('DELETE FROM {sequences} WHERE value < :value', array(':value' => $max_id));
}
// During testing, this function is called from shutdown with the
// simpletest prefix stored in $this->connection, and those tables are gone
// by the time shutdown is called so we need to ignore the database
// errors. There is no problem with completely ignoring errors here: if
// these queries fail, the sequence will work just fine, just use a bit
// more database storage and memory.
catch (PDOException $e) {
}
}
/**
* Overridden to work around issues to MySQL not supporting transactional DDL.
*/
protected function popCommittableTransactions() {
// Commit all the committable layers.
foreach (array_reverse($this->transactionLayers) as $name => $active) {
// Stop once we found an active transaction.
if ($active) {
break;
}
// If there are no more layers left then we should commit.
unset($this->transactionLayers[$name]);
if (empty($this->transactionLayers)) {
if (!$this->doCommit()) {
throw new DatabaseTransactionCommitFailedException();
}
}
else {
// Attempt to release this savepoint in the standard way.
try {
$this->query('RELEASE SAVEPOINT ' . $name);
}
catch (PDOException $e) {
// However, in MySQL (InnoDB), savepoints are automatically committed
// when tables are altered or created (DDL transactions are not
// supported). This can cause exceptions due to trying to release
// savepoints which no longer exist.
//
// To avoid exceptions when no actual error has occurred, we silently
// succeed for MySQL error code 1305 ("SAVEPOINT does not exist").
if ($e->errorInfo[1] == '1305') {
// If one SAVEPOINT was released automatically, then all were.
// Therefore, clean the transaction stack.
$this->transactionLayers = array();
// We also have to explain to PDO that the transaction stack has
// been cleaned-up.
$this->doCommit();
}
else {
throw $e;
}
}
}
}
}
/**
* Do the actual commit, including a workaround for PHP 8 behaviour changes.
*
* @return bool
* Success or otherwise of the commit.
*/
protected function doCommit() {
if ($this->connection->inTransaction()) {
return $this->connection->commit();
}
else {
// In PHP 8.0 a PDOException is thrown when a commit is attempted with no
// transaction active. In previous PHP versions this failed silently.
return TRUE;
}
}
/**
* {@inheritdoc}
*/
public function rollback($savepoint_name = 'drupal_transaction') {
// MySQL will automatically commit transactions when tables are altered or
// created (DDL transactions are not supported). Prevent triggering an
// exception to ensure that the error that has caused the rollback is
// properly reported.
if (!$this->connection->inTransaction()) {
// Before PHP 8 $this->connection->inTransaction() will return TRUE and
// $this->connection->rollback() does not throw an exception; the
// following code is unreachable.
// If \DatabaseConnection::rollback() would throw an
// exception then continue to throw an exception.
if (!$this->inTransaction()) {
throw new DatabaseTransactionNoActiveException();
}
// A previous rollback to an earlier savepoint may mean that the savepoint
// in question has already been accidentally committed.
if (!isset($this->transactionLayers[$savepoint_name])) {
throw new DatabaseTransactionNoActiveException();
}
trigger_error('Rollback attempted when there is no active transaction. This can cause data integrity issues.', E_USER_WARNING);
return;
}
return parent::rollback($savepoint_name);
}
public function utf8mb4IsConfigurable() {
return TRUE;
}
public function utf8mb4IsActive() {
return isset($this->connectionOptions['charset']) && $this->connectionOptions['charset'] === 'utf8mb4';
}
public function utf8mb4IsSupported() {
// Ensure that the MySQL driver supports utf8mb4 encoding.
$version = $this->connection->getAttribute(PDO::ATTR_CLIENT_VERSION);
if (strpos($version, 'mysqlnd') !== FALSE) {
// The mysqlnd driver supports utf8mb4 starting at version 5.0.9.
$version = preg_replace('/^\D+([\d.]+).*/', '$1', $version);
if (version_compare($version, '5.0.9', '<')) {
return FALSE;
}
}
else {
// The libmysqlclient driver supports utf8mb4 starting at version 5.5.3.
if (version_compare($version, '5.5.3', '<')) {
return FALSE;
}
}
// Ensure that the MySQL server supports large prefixes and utf8mb4.
try {
$this->query("CREATE TABLE {drupal_utf8mb4_test} (id VARCHAR(255), PRIMARY KEY(id(255))) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci ROW_FORMAT=DYNAMIC ENGINE=INNODB");
}
catch (Exception $e) {
return FALSE;
}
$this->query("DROP TABLE {drupal_utf8mb4_test}");
return TRUE;
}
}
/**
* @} End of "addtogroup database".
*/