Connection::getSchema() - Code Metrics - Inspection of "Fix missing query constructor" - yiisoft/db - Measure and Improve Code Quality continuously with Scrutinizer

Completed
Pull Request — master (#34)

unknown
created 2018-12-28 14:43 UTC
Connection::getSchema() A

↳ Parent: Connection
Complexity

Conditions	4
Paths	4
Size

Total Lines
Duplication

Lines	0
Ratio	0 %
Code Coverage

Tests	8
CRAP Score	4.0218
Importance

Changes
Metric	Value
dl	0
loc	16
ccs	8
cts	9
cp	0.8889
rs	9.7333
c	0
b	0
f	0
cc	4
nc	4
nop	0
crap	4.0218
<?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\base\Component;
use yii\exceptions\InvalidConfigException;
use yii\exceptions\NotSupportedException;
use yii\caching\CacheInterface;
use yii\helpers\Yii;

/**
 * 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::class,
 *         'dsn' => 'mysql:host=127.0.0.1;dbname=demo;charset=utf8',
 *         'username' => 'root',
 *         'password' => '',
 *     ],
 * ],
 * ```
 *
 * The [[dsn]] property can be defined via configuration array:
 *
 * ```php
 * 'components' => [
 *     'db' => [
 *         '__class' => \yii\db\Connection::class,
 *         'dsn' => [
 *             'driver' => 'mysql',
 *             'host' => '127.0.0.1',
 *             'dbname' => 'demo',
 *             'charset' => 'utf8',
 *          ],
 *         'username' => 'root',
 *         'password' => '',
 *     ],
 * ],
 * ```
 *
 * @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 <[email protected]>
 * @since 2.0
 */
class Connection extends Component implements ConnectionInterface
{
    /**
     * @event [[yii\base\Event|Event]] an event that is triggered after a DB connection is established
     */
    const EVENT_AFTER_OPEN = 'afterOpen';
    /**
     * @event [[yii\base\Event|Event]] an event that is triggered right before a top-level transaction is started
     */
    const EVENT_BEGIN_TRANSACTION = 'beginTransaction';
    /**
     * @event [[yii\base\Event|Event]] an event that is triggered right after a top-level transaction is committed
     */
    const EVENT_COMMIT_TRANSACTION = 'commitTransaction';
    /**
     * @event [[yii\base\Event|Event]] an event that is triggered right after a top-level transaction is rolled back
     */
    const EVENT_ROLLBACK_TRANSACTION = 'rollbackTransaction';

    /**
     * @var string|array 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`.
     *
     * Since version 3.0.0 an array can be passed to contruct a DSN string.
     * The `driver` array key is used as the driver prefix of the DSN,
     * all further key-value pairs are rendered as `key=value` and concatenated by `;`. For example:
     *
     * ```php
     * 'dsn' => [
     *     'driver' => 'mysql',
     *     'host' => '127.0.0.1',
     *     'dbname' => 'demo',
     *     'charset' => 'utf8',
     * ],
     * ```
     *
     * Will result in the DSN string `mysql:host=127.0.0.1;dbname=demo`.
     */
    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 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' => pgsql\Schema::class, // PostgreSQL
        'mysqli' => mysql\Schema::class, // MySQL
        'mysql' => mysql\Schema::class, // MySQL
        'sqlite' => sqlite\Schema::class, // sqlite 3
        'sqlite2' => sqlite\Schema::class, // sqlite 2
    ];
    /**
     * @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 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
    ];
    /**
     * @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 = [];


    /**
    * {@inheritdoc}
    */
    public function init()
    {
       if (is_array($this->dsn)) {
           $this->dsn = $this->buildDSN($this->dsn);
       }
       parent::init();
abstract class User
{
    /** @return string */
    abstract public function getPassword();
}

class MyUser extends User
{
    public function getPassword()
    {
        // return something
    }

    public function getDisplayName()
    {
        // return some name.
    }
}

class AuthSystem
{
    public function authenticate(User $user)
    {
        $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName()));
        // do something.
    }
}
    }

    /**
     * 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 \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 (\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 \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 (\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::getApp()) {

                $cache = Yii::getApp()->get($this->queryCache, false);

            } else {
                $cache = $this->queryCache;
            }
            if ($cache instanceof CacheInterface) {
if ($x instanceof DoesNotExist) {
    // Do something.
}
                return [$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') {
                    $pdoClass = mssql\PDO::class;
                } elseif ($driver === 'sqlsrv') {
                    $pdoClass = mssql\SqlsrvPDO::class;
                }
            }
        }

        $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.
     * 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);
        }
        $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();
        $config = ['__class' => Command::class];
        if (isset($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 = $this->_transaction = new Transaction($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 \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 (\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 iterable $config the [[QueryBuilder]] properties to be configured.
     * @since 2.0.14
     */
    public function setQueryBuilder(iterable $config)
    {
        $builder = $this->getQueryBuilder();
        foreach ($config as $key => $value) {
            $builder->{$key} = $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 \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 (\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::getApp()->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)) {
if ($x instanceof DoesNotExist) {
    // Do something.
}
                // 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) {
if ($x instanceof DoesNotExist) {
    // Do something.
}
                    // mark this server as dead and only retry it after the specified interval
                    $cache->set($key, 1, $this->serverRetryInterval);
                }
            }
        }

        return null;
    }

    /**
     * Build the Data Source Name or DSN
     * @param array $config the DSN configurations
     * @return string the formated DSN
     * @throws InvalidConfigException if 'driver' key was not defined
     */
    private function buildDSN(array $config)
    {
        if (isset($config['driver'])) {
            $driver = $config['driver'];
            unset($config['driver']);

            $parts = [];
            foreach ($config as $key => $value) {
                $parts[] = "$key=$value";
            }

            return "$driver:" . implode(';', $parts);
        }
        throw new InvalidConfigException("Connection DSN 'driver' must be set.");
    }

    /**
     * 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;
        }
    }
}

Pull Request — master (#34)

Connection::getSchema() A

Complexity

Size

Duplication

Code Coverage

Importance

Available Fixes

1. Missing dependencies

2. Missing use statement

1. Missing dependencies

2. Missing use statement

1. Missing dependencies

2. Missing use statement

yiisoft / db

Pull Request — master (#34)

Connection::getSchema() A

Complexity

Size

Duplication

Code Coverage

Importance

Available Fixes

1. Missing dependencies

2. Missing use statement

1. Missing dependencies

2. Missing use statement

1. Missing dependencies

2. Missing use statement

Duplication Side-by-Side

Filter issues like
