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<?php
/**
* @link http://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
namespace yii\db;
use PDO;
use Yii;
use yii\base\Component;
use yii\base\InvalidConfigException;
use yii\base\NotSupportedException;
use yii\caching\CacheInterface;
/**
* Connection represents a connection to a database via [PDO](http://php.net/manual/en/book.pdo.php).
*
* Connection works together with [[Command]], [[DataReader]] and [[Transaction]]
* to provide data access to various DBMS in a common set of APIs. They are a thin wrapper
* of the [PDO PHP extension](http://php.net/manual/en/book.pdo.php).
*
* Connection supports database replication and read-write splitting. In particular, a Connection component
* can be configured with multiple [[masters]] and [[slaves]]. It will do load balancing and failover by choosing
* appropriate servers. It will also automatically direct read operations to the slaves and write operations to
* the masters.
*
* To establish a DB connection, set [[dsn]], [[username]] and [[password]], and then
* call [[open()]] to connect to the database server. The current state of the connection can be checked using [[$isActive]].
*
* The following example shows how to create a Connection instance and establish
* the DB connection:
*
* ```php
* $connection = new \yii\db\Connection([
* 'dsn' => $dsn,
* 'username' => $username,
* 'password' => $password,
* ]);
* $connection->open();
* ```
*
* After the DB connection is established, one can execute SQL statements like the following:
*
* ```php
* $command = $connection->createCommand('SELECT * FROM post');
* $posts = $command->queryAll();
* $command = $connection->createCommand('UPDATE post SET status=1');
* $command->execute();
* ```
*
* One can also do prepared SQL execution and bind parameters to the prepared SQL.
* When the parameters are coming from user input, you should use this approach
* to prevent SQL injection attacks. The following is an example:
*
* ```php
* $command = $connection->createCommand('SELECT * FROM post WHERE id=:id');
* $command->bindValue(':id', $_GET['id']);
* $post = $command->query();
* ```
*
* For more information about how to perform various DB queries, please refer to [[Command]].
*
* If the underlying DBMS supports transactions, you can perform transactional SQL queries
* like the following:
*
* ```php
* $transaction = $connection->beginTransaction();
* try {
* $connection->createCommand($sql1)->execute();
* $connection->createCommand($sql2)->execute();
* // ... executing other SQL statements ...
* $transaction->commit();
* } catch (Exception $e) {
* $transaction->rollBack();
* }
* ```
*
* You also can use shortcut for the above like the following:
*
* ```php
* $connection->transaction(function () {
* $order = new Order($customer);
* $order->save();
* $order->addItems($items);
* });
* ```
*
* If needed you can pass transaction isolation level as a second parameter:
*
* ```php
* $connection->transaction(function (Connection $db) {
* //return $db->...
* }, Transaction::READ_UNCOMMITTED);
* ```
*
* Connection is often used as an application component and configured in the application
* configuration like the following:
*
* ```php
* 'components' => [
* 'db' => [
* 'class' => '\yii\db\Connection',
* 'dsn' => 'mysql:host=127.0.0.1;dbname=demo',
* 'username' => 'root',
* 'password' => '',
* 'charset' => 'utf8',
* ],
* ],
* ```
*
* @property string $driverName Name of the DB driver.
* @property bool $isActive Whether the DB connection is established. This property is read-only.
* @property string $lastInsertID The row ID of the last row inserted, or the last value retrieved from the
* sequence object. This property is read-only.
* @property Connection $master The currently active master connection. `null` is returned if there is no
* master available. This property is read-only.
* @property PDO $masterPdo The PDO instance for the currently active master connection. This property is
* read-only.
* @property QueryBuilder $queryBuilder The query builder for the current DB connection. Note that the type of
* this property differs in getter and setter. See [[getQueryBuilder()]] and [[setQueryBuilder()]] for details.
* @property Schema $schema The schema information for the database opened by this connection. This property
* is read-only.
* @property string $serverVersion Server version as a string. This property is read-only.
* @property Connection $slave The currently active slave connection. `null` is returned if there is no slave
* available and `$fallbackToMaster` is false. This property is read-only.
* @property PDO $slavePdo The PDO instance for the currently active slave connection. `null` is returned if
* no slave connection is available and `$fallbackToMaster` is false. This property is read-only.
* @property Transaction|null $transaction The currently active transaction. Null if no active transaction.
* This property is read-only.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class Connection extends Component
{
/**
* @event yii\base\Event an event that is triggered after a DB connection is established
*/
const EVENT_AFTER_OPEN = 'afterOpen';
/**
* @event yii\base\Event an event that is triggered right before a top-level transaction is started
*/
const EVENT_BEGIN_TRANSACTION = 'beginTransaction';
/**
* @event yii\base\Event an event that is triggered right after a top-level transaction is committed
*/
const EVENT_COMMIT_TRANSACTION = 'commitTransaction';
/**
* @event yii\base\Event an event that is triggered right after a top-level transaction is rolled back
*/
const EVENT_ROLLBACK_TRANSACTION = 'rollbackTransaction';
/**
* @var string the Data Source Name, or DSN, contains the information required to connect to the database.
* Please refer to the [PHP manual](http://php.net/manual/en/pdo.construct.php) on
* the format of the DSN string.
*
* For [SQLite](http://php.net/manual/en/ref.pdo-sqlite.connection.php) you may use a [path alias](guide:concept-aliases)
* for specifying the database path, e.g. `sqlite:@app/data/db.sql`.
*
* @see charset
*/
public $dsn;
/**
* @var string the username for establishing DB connection. Defaults to `null` meaning no username to use.
*/
public $username;
/**
* @var string the password for establishing DB connection. Defaults to `null` meaning no password to use.
*/
public $password;
/**
* @var array PDO attributes (name => value) that should be set when calling [[open()]]
* to establish a DB connection. Please refer to the
* [PHP manual](http://php.net/manual/en/pdo.setattribute.php) for
* details about available attributes.
*/
public $attributes;
/**
* @var PDO the PHP PDO instance associated with this DB connection.
* This property is mainly managed by [[open()]] and [[close()]] methods.
* When a DB connection is active, this property will represent a PDO instance;
* otherwise, it will be null.
* @see pdoClass
*/
public $pdo;
/**
* @var bool whether to enable schema caching.
* Note that in order to enable truly schema caching, a valid cache component as specified
* by [[schemaCache]] must be enabled and [[enableSchemaCache]] must be set true.
* @see schemaCacheDuration
* @see schemaCacheExclude
* @see schemaCache
*/
public $enableSchemaCache = false;
/**
* @var int number of seconds that table metadata can remain valid in cache.
* Use 0 to indicate that the cached data will never expire.
* @see enableSchemaCache
*/
public $schemaCacheDuration = 3600;
/**
* @var array list of tables whose metadata should NOT be cached. Defaults to empty array.
* The table names may contain schema prefix, if any. Do not quote the table names.
* @see enableSchemaCache
*/
public $schemaCacheExclude = [];
/**
* @var CacheInterface|string the cache object or the ID of the cache application component that
* is used to cache the table metadata.
* @see enableSchemaCache
*/
public $schemaCache = 'cache';
/**
* @var bool whether to enable query caching.
* Note that in order to enable query caching, a valid cache component as specified
* by [[queryCache]] must be enabled and [[enableQueryCache]] must be set true.
* Also, only the results of the queries enclosed within [[cache()]] will be cached.
* @see queryCache
* @see cache()
* @see noCache()
*/
public $enableQueryCache = true;
/**
* @var int the default number of seconds that query results can remain valid in cache.
* Defaults to 3600, meaning 3600 seconds, or one hour. Use 0 to indicate that the cached data will never expire.
* The value of this property will be used when [[cache()]] is called without a cache duration.
* @see enableQueryCache
* @see cache()
*/
public $queryCacheDuration = 3600;
/**
* @var CacheInterface|string the cache object or the ID of the cache application component
* that is used for query caching.
* @see enableQueryCache
*/
public $queryCache = 'cache';
/**
* @var string the charset used for database connection. The property is only used
* for MySQL, PostgreSQL and CUBRID databases. Defaults to null, meaning using default charset
* as configured by the database.
*
* For Oracle Database, the charset must be specified in the [[dsn]], for example for UTF-8 by appending `;charset=UTF-8`
* to the DSN string.
*
* The same applies for if you're using GBK or BIG5 charset with MySQL, then it's highly recommended to
* specify charset via [[dsn]] like `'mysql:dbname=mydatabase;host=127.0.0.1;charset=GBK;'`.
*/
public $charset;
/**
* @var bool whether to turn on prepare emulation. Defaults to false, meaning PDO
* will use the native prepare support if available. For some databases (such as MySQL),
* this may need to be set true so that PDO can emulate the prepare support to bypass
* the buggy native prepare support.
* The default value is null, which means the PDO ATTR_EMULATE_PREPARES value will not be changed.
*/
public $emulatePrepare;
/**
* @var string the common prefix or suffix for table names. If a table name is given
* as `{{%TableName}}`, then the percentage character `%` will be replaced with this
* property value. For example, `{{%post}}` becomes `{{tbl_post}}`.
*/
public $tablePrefix = '';
/**
* @var array mapping between PDO driver names and [[Schema]] classes.
* The keys of the array are PDO driver names while the values are either the corresponding
* schema class names or configurations. Please refer to [[Yii::createObject()]] for
* details on how to specify a configuration.
*
* This property is mainly used by [[getSchema()]] when fetching the database schema information.
* You normally do not need to set this property unless you want to use your own
* [[Schema]] class to support DBMS that is not supported by Yii.
*/
public $schemaMap = [
'pgsql' => 'yii\db\pgsql\Schema', // PostgreSQL
'mysqli' => 'yii\db\mysql\Schema', // MySQL
'mysql' => 'yii\db\mysql\Schema', // MySQL
'sqlite' => 'yii\db\sqlite\Schema', // sqlite 3
'sqlite2' => 'yii\db\sqlite\Schema', // sqlite 2
'sqlsrv' => 'yii\db\mssql\Schema', // newer MSSQL driver on MS Windows hosts
'oci' => 'yii\db\oci\Schema', // Oracle driver
'mssql' => 'yii\db\mssql\Schema', // older MSSQL driver on MS Windows hosts
'dblib' => 'yii\db\mssql\Schema', // dblib drivers on GNU/Linux (and maybe other OSes) hosts
'cubrid' => 'yii\db\cubrid\Schema', // CUBRID
];
/**
* @var string Custom PDO wrapper class. If not set, it will use [[PDO]] or [[\yii\db\mssql\PDO]] when MSSQL is used.
* @see pdo
*/
public $pdoClass;
/**
* @var string the class used to create new database [[Command]] objects. If you want to extend the [[Command]] class,
* you may configure this property to use your extended version of the class.
* Since version 2.0.14 [[$commandMap]] is used if this property is set to its default value.
* @see createCommand
* @since 2.0.7
* @deprecated since 2.0.14. Use [[$commandMap]] for precise configuration.
*/
public $commandClass = 'yii\db\Command';
/**
* @var array mapping between PDO driver names and [[Command]] classes.
* The keys of the array are PDO driver names while the values are either the corresponding
* command class names or configurations. Please refer to [[Yii::createObject()]] for
* details on how to specify a configuration.
*
* This property is mainly used by [[createCommand()]] to create new database [[Command]] objects.
* You normally do not need to set this property unless you want to use your own
* [[Command]] class or support DBMS that is not supported by Yii.
* @since 2.0.14
*/
public $commandMap = [
'pgsql' => 'yii\db\Command', // PostgreSQL
'mysqli' => 'yii\db\Command', // MySQL
'mysql' => 'yii\db\Command', // MySQL
'sqlite' => 'yii\db\sqlite\Command', // sqlite 3
'sqlite2' => 'yii\db\sqlite\Command', // sqlite 2
'sqlsrv' => 'yii\db\Command', // newer MSSQL driver on MS Windows hosts
'oci' => 'yii\db\Command', // Oracle driver
'mssql' => 'yii\db\Command', // older MSSQL driver on MS Windows hosts
'dblib' => 'yii\db\Command', // dblib drivers on GNU/Linux (and maybe other OSes) hosts
'cubrid' => 'yii\db\Command', // CUBRID
];
/**
* @var bool whether to enable [savepoint](http://en.wikipedia.org/wiki/Savepoint).
* Note that if the underlying DBMS does not support savepoint, setting this property to be true will have no effect.
*/
public $enableSavepoint = true;
/**
* @var CacheInterface|string|false the cache object or the ID of the cache application component that is used to store
* the health status of the DB servers specified in [[masters]] and [[slaves]].
* This is used only when read/write splitting is enabled or [[masters]] is not empty.
* Set boolean `false` to disabled server status caching.
*/
public $serverStatusCache = 'cache';
/**
* @var int the retry interval in seconds for dead servers listed in [[masters]] and [[slaves]].
* This is used together with [[serverStatusCache]].
*/
public $serverRetryInterval = 600;
/**
* @var bool whether to enable read/write splitting by using [[slaves]] to read data.
* Note that if [[slaves]] is empty, read/write splitting will NOT be enabled no matter what value this property takes.
*/
public $enableSlaves = true;
/**
* @var array list of slave connection configurations. Each configuration is used to create a slave DB connection.
* When [[enableSlaves]] is true, one of these configurations will be chosen and used to create a DB connection
* for performing read queries only.
* @see enableSlaves
* @see slaveConfig
*/
public $slaves = [];
/**
* @var array the configuration that should be merged with every slave configuration listed in [[slaves]].
* For example,
*
* ```php
* [
* 'username' => 'slave',
* 'password' => 'slave',
* 'attributes' => [
* // use a smaller connection timeout
* PDO::ATTR_TIMEOUT => 10,
* ],
* ]
* ```
*/
public $slaveConfig = [];
/**
* @var array list of master connection configurations. Each configuration is used to create a master DB connection.
* When [[open()]] is called, one of these configurations will be chosen and used to create a DB connection
* which will be used by this object.
* Note that when this property is not empty, the connection setting (e.g. "dsn", "username") of this object will
* be ignored.
* @see masterConfig
* @see shuffleMasters
*/
public $masters = [];
/**
* @var array the configuration that should be merged with every master configuration listed in [[masters]].
* For example,
*
* ```php
* [
* 'username' => 'master',
* 'password' => 'master',
* 'attributes' => [
* // use a smaller connection timeout
* PDO::ATTR_TIMEOUT => 10,
* ],
* ]
* ```
*/
public $masterConfig = [];
/**
* @var bool whether to shuffle [[masters]] before getting one.
* @since 2.0.11
* @see masters
*/
public $shuffleMasters = true;
/**
* @var bool whether to enable logging of database queries. Defaults to true.
* You may want to disable this option in a production environment to gain performance
* if you do not need the information being logged.
* @since 2.0.12
* @see enableProfiling
*/
public $enableLogging = true;
/**
* @var bool whether to enable profiling of opening database connection and database queries. Defaults to true.
* You may want to disable this option in a production environment to gain performance
* if you do not need the information being logged.
* @since 2.0.12
* @see enableLogging
*/
public $enableProfiling = true;
/**
* @var Transaction the currently active transaction
*/
private $_transaction;
/**
* @var Schema the database schema
*/
private $_schema;
/**
* @var string driver name
*/
private $_driverName;
/**
* @var Connection|false the currently active master connection
*/
private $_master = false;
/**
* @var Connection|false the currently active slave connection
*/
private $_slave = false;
/**
* @var array query cache parameters for the [[cache()]] calls
*/
private $_queryCacheInfo = [];
/**
* Returns a value indicating whether the DB connection is established.
* @return bool whether the DB connection is established
*/
public function getIsActive()
{
return $this->pdo !== null;
}
/**
* Uses query cache for the queries performed with the callable.
*
* When query caching is enabled ([[enableQueryCache]] is true and [[queryCache]] refers to a valid cache),
* queries performed within the callable will be cached and their results will be fetched from cache if available.
* For example,
*
* ```php
* // The customer will be fetched from cache if available.
* // If not, the query will be made against DB and cached for use next time.
* $customer = $db->cache(function (Connection $db) {
* return $db->createCommand('SELECT * FROM customer WHERE id=1')->queryOne();
* });
* ```
*
* Note that query cache is only meaningful for queries that return results. For queries performed with
* [[Command::execute()]], query cache will not be used.
*
* @param callable $callable a PHP callable that contains DB queries which will make use of query cache.
* The signature of the callable is `function (Connection $db)`.
* @param int $duration the number of seconds that query results can remain valid in the cache. If this is
* not set, the value of [[queryCacheDuration]] will be used instead.
* Use 0 to indicate that the cached data will never expire.
* @param \yii\caching\Dependency $dependency the cache dependency associated with the cached query results.
* @return mixed the return result of the callable
* @throws \Exception|\Throwable if there is any exception during query
* @see enableQueryCache
* @see queryCache
* @see noCache()
*/
public function cache(callable $callable, $duration = null, $dependency = null)
{
$this->_queryCacheInfo[] = [$duration === null ? $this->queryCacheDuration : $duration, $dependency];
try {
$result = call_user_func($callable, $this);
array_pop($this->_queryCacheInfo);
return $result;
} catch (\Exception $e) {
array_pop($this->_queryCacheInfo);
throw $e;
} catch (\Throwable $e) {
array_pop($this->_queryCacheInfo);
throw $e;
}
}
/**
* Disables query cache temporarily.
*
* Queries performed within the callable will not use query cache at all. For example,
*
* ```php
* $db->cache(function (Connection $db) {
*
* // ... queries that use query cache ...
*
* return $db->noCache(function (Connection $db) {
* // this query will not use query cache
* return $db->createCommand('SELECT * FROM customer WHERE id=1')->queryOne();
* });
* });
* ```
*
* @param callable $callable a PHP callable that contains DB queries which should not use query cache.
* The signature of the callable is `function (Connection $db)`.
* @return mixed the return result of the callable
* @throws \Exception|\Throwable if there is any exception during query
* @see enableQueryCache
* @see queryCache
* @see cache()
*/
public function noCache(callable $callable)
{
$this->_queryCacheInfo[] = false;
try {
$result = call_user_func($callable, $this);
array_pop($this->_queryCacheInfo);
return $result;
} catch (\Exception $e) {
array_pop($this->_queryCacheInfo);
throw $e;
} catch (\Throwable $e) {
array_pop($this->_queryCacheInfo);
throw $e;
}
}
/**
* Returns the current query cache information.
* This method is used internally by [[Command]].
* @param int $duration the preferred caching duration. If null, it will be ignored.
* @param \yii\caching\Dependency $dependency the preferred caching dependency. If null, it will be ignored.
* @return array the current query cache information, or null if query cache is not enabled.
* @internal
*/
public function getQueryCacheInfo($duration, $dependency)
{
if (!$this->enableQueryCache) {
return null;
}
$info = end($this->_queryCacheInfo);
if (is_array($info)) {
if ($duration === null) {
$duration = $info[0];
}
if ($dependency === null) {
$dependency = $info[1];
}
}
if ($duration === 0 || $duration > 0) {
if (is_string($this->queryCache) && Yii::$app) {
$cache = Yii::$app->get($this->queryCache, false);
} else {
$cache = $this->queryCache;
}
if ($cache instanceof CacheInterface) {
return [$cache, $duration, $dependency];
}
}
return null;
}
/**
* Establishes a DB connection.
* It does nothing if a DB connection has already been established.
* @throws Exception if connection fails
*/
public function open()
{
if ($this->pdo !== null) {
return;
}
if (!empty($this->masters)) {
$db = $this->getMaster();
if ($db !== null) {
$this->pdo = $db->pdo;
return;
}
throw new InvalidConfigException('None of the master DB servers is available.');
}
if (empty($this->dsn)) {
throw new InvalidConfigException('Connection::dsn cannot be empty.');
}
$token = 'Opening DB connection: ' . $this->dsn;
$enableProfiling = $this->enableProfiling;
try {
Yii::info($token, __METHOD__);
if ($enableProfiling) {
Yii::beginProfile($token, __METHOD__);
}
$this->pdo = $this->createPdoInstance();
$this->initConnection();
if ($enableProfiling) {
Yii::endProfile($token, __METHOD__);
}
} catch (\PDOException $e) {
if ($enableProfiling) {
Yii::endProfile($token, __METHOD__);
}
throw new Exception($e->getMessage(), $e->errorInfo, (int) $e->getCode(), $e);
}
}
/**
* Closes the currently active DB connection.
* It does nothing if the connection is already closed.
*/
public function close()
{
if ($this->_master) {
if ($this->pdo === $this->_master->pdo) {
$this->pdo = null;
}
$this->_master->close();
$this->_master = false;
}
if ($this->pdo !== null) {
Yii::debug('Closing DB connection: ' . $this->dsn, __METHOD__);
$this->pdo = null;
$this->_schema = null;
$this->_transaction = null;
}
if ($this->_slave) {
$this->_slave->close();
$this->_slave = false;
}
}
/**
* Creates the PDO instance.
* This method is called by [[open]] to establish a DB connection.
* The default implementation will create a PHP PDO instance.
* You may override this method if the default PDO needs to be adapted for certain DBMS.
* @return PDO the pdo instance
*/
protected function createPdoInstance()
{
$pdoClass = $this->pdoClass;
if ($pdoClass === null) {
$pdoClass = 'PDO';
if ($this->_driverName !== null) {
$driver = $this->_driverName;
} elseif (($pos = strpos($this->dsn, ':')) !== false) {
$driver = strtolower(substr($this->dsn, 0, $pos));
}
if (isset($driver)) {
if ($driver === 'mssql' || $driver === 'dblib') {
$pdoClass = 'yii\db\mssql\PDO';
} elseif ($driver === 'sqlsrv') {
$pdoClass = 'yii\db\mssql\SqlsrvPDO';
}
}
}
$dsn = $this->dsn;
if (strncmp('sqlite:@', $dsn, 8) === 0) {
$dsn = 'sqlite:' . Yii::getAlias(substr($dsn, 7));
}
return new $pdoClass($dsn, $this->username, $this->password, $this->attributes);
}
/**
* Initializes the DB connection.
* This method is invoked right after the DB connection is established.
* The default implementation turns on `PDO::ATTR_EMULATE_PREPARES`
* if [[emulatePrepare]] is true, and sets the database [[charset]] if it is not empty.
* It then triggers an [[EVENT_AFTER_OPEN]] event.
*/
protected function initConnection()
{
$this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
if ($this->emulatePrepare !== null && constant('PDO::ATTR_EMULATE_PREPARES')) {
$this->pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->emulatePrepare);
}
if ($this->charset !== null && in_array($this->getDriverName(), ['pgsql', 'mysql', 'mysqli', 'cubrid'], true)) {
$this->pdo->exec('SET NAMES ' . $this->pdo->quote($this->charset));
}
$this->trigger(self::EVENT_AFTER_OPEN);
}
/**
* Creates a command for execution.
* @param string $sql the SQL statement to be executed
* @param array $params the parameters to be bound to the SQL statement
* @return Command the DB command
*/
public function createCommand($sql = null, $params = [])
{
$driver = $this->getDriverName();
$config = ['class' => 'yii\db\Command'];
if ($this->commandClass !== $config['class']) {
$config['class'] = $this->commandClass;
} elseif (isset($this->commandMap[$driver])) {
$config = !is_array($this->commandMap[$driver]) ? ['class' => $this->commandMap[$driver]] : $this->commandMap[$driver];
}
$config['db'] = $this;
$config['sql'] = $sql;
/** @var Command $command */
$command = Yii::createObject($config);
return $command->bindValues($params);
}
/**
* Returns the currently active transaction.
* @return Transaction|null the currently active transaction. Null if no active transaction.
*/
public function getTransaction()
{
return $this->_transaction && $this->_transaction->getIsActive() ? $this->_transaction : null;
}
/**
* Starts a transaction.
* @param string|null $isolationLevel The isolation level to use for this transaction.
* See [[Transaction::begin()]] for details.
* @return Transaction the transaction initiated
*/
public function beginTransaction($isolationLevel = null)
{
$this->open();
if (($transaction = $this->getTransaction()) === null) {
$transaction = $this->_transaction = new Transaction(['db' => $this]);
}
$transaction->begin($isolationLevel);
return $transaction;
}
/**
* Executes callback provided in a transaction.
*
* @param callable $callback a valid PHP callback that performs the job. Accepts connection instance as parameter.
* @param string|null $isolationLevel The isolation level to use for this transaction.
* See [[Transaction::begin()]] for details.
* @throws \Exception|\Throwable if there is any exception during query. In this case the transaction will be rolled back.
* @return mixed result of callback function
*/
public function transaction(callable $callback, $isolationLevel = null)
{
$transaction = $this->beginTransaction($isolationLevel);
$level = $transaction->level;
try {
$result = call_user_func($callback, $this);
if ($transaction->isActive && $transaction->level === $level) {
$transaction->commit();
}
} catch (\Exception $e) {
$this->rollbackTransactionOnLevel($transaction, $level);
throw $e;
} catch (\Throwable $e) {
$this->rollbackTransactionOnLevel($transaction, $level);
throw $e;
}
return $result;
}
/**
* Rolls back given [[Transaction]] object if it's still active and level match.
* In some cases rollback can fail, so this method is fail safe. Exception thrown
* from rollback will be caught and just logged with [[\Yii::error()]].
* @param Transaction $transaction Transaction object given from [[beginTransaction()]].
* @param int $level Transaction level just after [[beginTransaction()]] call.
*/
private function rollbackTransactionOnLevel($transaction, $level)
{
if ($transaction->isActive && $transaction->level === $level) {
// https://github.com/yiisoft/yii2/pull/13347
try {
$transaction->rollBack();
} catch (\Exception $e) {
\Yii::error($e, __METHOD__);
// hide this exception to be able to continue throwing original exception outside
}
}
}
/**
* Returns the schema information for the database opened by this connection.
* @return Schema the schema information for the database opened by this connection.
* @throws NotSupportedException if there is no support for the current driver type
*/
public function getSchema()
{
if ($this->_schema !== null) {
return $this->_schema;
}
$driver = $this->getDriverName();
if (isset($this->schemaMap[$driver])) {
$config = !is_array($this->schemaMap[$driver]) ? ['class' => $this->schemaMap[$driver]] : $this->schemaMap[$driver];
$config['db'] = $this;
return $this->_schema = Yii::createObject($config);
}
throw new NotSupportedException("Connection does not support reading schema information for '$driver' DBMS.");
}
/**
* Returns the query builder for the current DB connection.
* @return QueryBuilder the query builder for the current DB connection.
*/
public function getQueryBuilder()
{
return $this->getSchema()->getQueryBuilder();
}
/**
* Can be used to set [[QueryBuilder]] configuration via Connection configuration array.
*
* @param array $value the [[QueryBuilder]] properties to be configured.
* @since 2.0.14
*/
public function setQueryBuilder($value)
{
Yii::configure($this->getQueryBuilder(), $value);
}
/**
* Obtains the schema information for the named table.
* @param string $name table name.
* @param bool $refresh whether to reload the table schema even if it is found in the cache.
* @return TableSchema table schema information. Null if the named table does not exist.
*/
public function getTableSchema($name, $refresh = false)
{
return $this->getSchema()->getTableSchema($name, $refresh);
}
/**
* Returns the ID of the last inserted row or sequence value.
* @param string $sequenceName name of the sequence object (required by some DBMS)
* @return string the row ID of the last row inserted, or the last value retrieved from the sequence object
* @see http://php.net/manual/en/pdo.lastinsertid.php
*/
public function getLastInsertID($sequenceName = '')
{
return $this->getSchema()->getLastInsertID($sequenceName);
}
/**
* Quotes a string value for use in a query.
* Note that if the parameter is not a string, it will be returned without change.
* @param string $value string to be quoted
* @return string the properly quoted string
* @see http://php.net/manual/en/pdo.quote.php
*/
public function quoteValue($value)
{
return $this->getSchema()->quoteValue($value);
}
/**
* Quotes a table name for use in a query.
* If the table name contains schema prefix, the prefix will also be properly quoted.
* If the table name is already quoted or contains special characters including '(', '[[' and '{{',
* then this method will do nothing.
* @param string $name table name
* @return string the properly quoted table name
*/
public function quoteTableName($name)
{
return $this->getSchema()->quoteTableName($name);
}
/**
* Quotes a column name for use in a query.
* If the column name contains prefix, the prefix will also be properly quoted.
* If the column name is already quoted or contains special characters including '(', '[[' and '{{',
* then this method will do nothing.
* @param string $name column name
* @return string the properly quoted column name
*/
public function quoteColumnName($name)
{
return $this->getSchema()->quoteColumnName($name);
}
/**
* Processes a SQL statement by quoting table and column names that are enclosed within double brackets.
* Tokens enclosed within double curly brackets are treated as table names, while
* tokens enclosed within double square brackets are column names. They will be quoted accordingly.
* Also, the percentage character "%" at the beginning or ending of a table name will be replaced
* with [[tablePrefix]].
* @param string $sql the SQL to be quoted
* @return string the quoted SQL
*/
public function quoteSql($sql)
{
return preg_replace_callback(
'/(\\{\\{(%?[\w\-\. ]+%?)\\}\\}|\\[\\[([\w\-\. ]+)\\]\\])/',
function ($matches) {
if (isset($matches[3])) {
return $this->quoteColumnName($matches[3]);
}
return str_replace('%', $this->tablePrefix, $this->quoteTableName($matches[2]));
},
$sql
);
}
/**
* Returns the name of the DB driver. Based on the the current [[dsn]], in case it was not set explicitly
* by an end user.
* @return string name of the DB driver
*/
public function getDriverName()
{
if ($this->_driverName === null) {
if (($pos = strpos($this->dsn, ':')) !== false) {
$this->_driverName = strtolower(substr($this->dsn, 0, $pos));
} else {
$this->_driverName = strtolower($this->getSlavePdo()->getAttribute(PDO::ATTR_DRIVER_NAME));
}
}
return $this->_driverName;
}
/**
* Changes the current driver name.
* @param string $driverName name of the DB driver
*/
public function setDriverName($driverName)
{
$this->_driverName = strtolower($driverName);
}
/**
* Returns a server version as a string comparable by [[\version_compare()]].
* @return string server version as a string.
* @since 2.0.14
*/
public function getServerVersion()
{
return $this->getSchema()->getServerVersion();
}
/**
* Returns the PDO instance for the currently active slave connection.
* When [[enableSlaves]] is true, one of the slaves will be used for read queries, and its PDO instance
* will be returned by this method.
* @param bool $fallbackToMaster whether to return a master PDO in case none of the slave connections is available.
* @return PDO the PDO instance for the currently active slave connection. `null` is returned if no slave connection
* is available and `$fallbackToMaster` is false.
*/
public function getSlavePdo($fallbackToMaster = true)
{
$db = $this->getSlave(false);
if ($db === null) {
return $fallbackToMaster ? $this->getMasterPdo() : null;
}
return $db->pdo;
}
/**
* Returns the PDO instance for the currently active master connection.
* This method will open the master DB connection and then return [[pdo]].
* @return PDO the PDO instance for the currently active master connection.
*/
public function getMasterPdo()
{
$this->open();
return $this->pdo;
}
/**
* Returns the currently active slave connection.
* If this method is called for the first time, it will try to open a slave connection when [[enableSlaves]] is true.
* @param bool $fallbackToMaster whether to return a master connection in case there is no slave connection available.
* @return Connection the currently active slave connection. `null` is returned if there is no slave available and
* `$fallbackToMaster` is false.
*/
public function getSlave($fallbackToMaster = true)
{
if (!$this->enableSlaves) {
return $fallbackToMaster ? $this : null;
}
if ($this->_slave === false) {
$this->_slave = $this->openFromPool($this->slaves, $this->slaveConfig);
}
return $this->_slave === null && $fallbackToMaster ? $this : $this->_slave;
}
/**
* Returns the currently active master connection.
* If this method is called for the first time, it will try to open a master connection.
* @return Connection the currently active master connection. `null` is returned if there is no master available.
* @since 2.0.11
*/
public function getMaster()
{
if ($this->_master === false) {
$this->_master = $this->shuffleMasters
? $this->openFromPool($this->masters, $this->masterConfig)
: $this->openFromPoolSequentially($this->masters, $this->masterConfig);
}
return $this->_master;
}
/**
* Executes the provided callback by using the master connection.
*
* This method is provided so that you can temporarily force using the master connection to perform
* DB operations even if they are read queries. For example,
*
* ```php
* $result = $db->useMaster(function ($db) {
* return $db->createCommand('SELECT * FROM user LIMIT 1')->queryOne();
* });
* ```
*
* @param callable $callback a PHP callable to be executed by this method. Its signature is
* `function (Connection $db)`. Its return value will be returned by this method.
* @return mixed the return value of the callback
* @throws \Exception|\Throwable if there is any exception thrown from the callback
*/
public function useMaster(callable $callback)
{
if ($this->enableSlaves) {
$this->enableSlaves = false;
try {
$result = call_user_func($callback, $this);
} catch (\Exception $e) {
$this->enableSlaves = true;
throw $e;
} catch (\Throwable $e) {
$this->enableSlaves = true;
throw $e;
}
// TODO: use "finally" keyword when miminum required PHP version is >= 5.5
$this->enableSlaves = true;
} else {
$result = call_user_func($callback, $this);
}
return $result;
}
/**
* Opens the connection to a server in the pool.
* This method implements the load balancing among the given list of the servers.
* Connections will be tried in random order.
* @param array $pool the list of connection configurations in the server pool
* @param array $sharedConfig the configuration common to those given in `$pool`.
* @return Connection the opened DB connection, or `null` if no server is available
* @throws InvalidConfigException if a configuration does not specify "dsn"
*/
protected function openFromPool(array $pool, array $sharedConfig)
{
shuffle($pool);
return $this->openFromPoolSequentially($pool, $sharedConfig);
}
/**
* Opens the connection to a server in the pool.
* This method implements the load balancing among the given list of the servers.
* Connections will be tried in sequential order.
* @param array $pool the list of connection configurations in the server pool
* @param array $sharedConfig the configuration common to those given in `$pool`.
* @return Connection the opened DB connection, or `null` if no server is available
* @throws InvalidConfigException if a configuration does not specify "dsn"
* @since 2.0.11
*/
protected function openFromPoolSequentially(array $pool, array $sharedConfig)
{
if (empty($pool)) {
return null;
}
if (!isset($sharedConfig['class'])) {
$sharedConfig['class'] = get_class($this);
}
$cache = is_string($this->serverStatusCache) ? Yii::$app->get($this->serverStatusCache, false) : $this->serverStatusCache;
foreach ($pool as $config) {
$config = array_merge($sharedConfig, $config);
if (empty($config['dsn'])) {
throw new InvalidConfigException('The "dsn" option must be specified.');
}
$key = [__METHOD__, $config['dsn']];
if ($cache instanceof CacheInterface && $cache->get($key)) {
// should not try this dead server now
continue;
}
/* @var $db Connection */
$db = Yii::createObject($config);
try {
$db->open();
return $db;
} catch (\Exception $e) {
Yii::warning("Connection ({$config['dsn']}) failed: " . $e->getMessage(), __METHOD__);
if ($cache instanceof CacheInterface) {
// mark this server as dead and only retry it after the specified interval
$cache->set($key, 1, $this->serverRetryInterval);
}
}
}
return null;
}
/**
* Close the connection before serializing.
* @return array
*/
public function __sleep()
{
$fields = (array) $this;
unset($fields['pdo']);
unset($fields["\000" . __CLASS__ . "\000" . '_master']);
unset($fields["\000" . __CLASS__ . "\000" . '_slave']);
unset($fields["\000" . __CLASS__ . "\000" . '_transaction']);
unset($fields["\000" . __CLASS__ . "\000" . '_schema']);
return array_keys($fields);
}
/**
* Reset the connection after cloning.
*/
public function __clone()
{
parent::__clone();
$this->_master = false;
$this->_slave = false;
$this->_schema = null;
$this->_transaction = null;
if (strncmp($this->dsn, 'sqlite::memory:', 15) !== 0) {
// reset PDO connection, unless its sqlite in-memory, which can only have one connection
$this->pdo = null;
}
}
}