statementClass = NULL; // This driver defaults to transaction support, except if explicitly passed FALSE. $this->transactionSupport = $this->transactionalDDLSupport = !isset($connection_options['transactions']) || $connection_options['transactions'] !== FALSE; $this->connectionOptions = $connection_options; // Allow PDO options to be overridden. $connection_options += array( 'pdo' => array(), ); $connection_options['pdo'] += array( // Convert numeric values to strings when fetching. PDO::ATTR_STRINGIFY_FETCHES => TRUE, ); parent::__construct('sqlite:' . $connection_options['database'], '', '', $connection_options['pdo']); // Attach one database for each registered prefix. $prefixes = $this->prefixes; foreach ($prefixes as $table => &$prefix) { // Empty prefix means query the main database -- no need to attach anything. if (!empty($prefix)) { // Only attach the database once. if (!isset($this->attachedDatabases[$prefix])) { $this->attachedDatabases[$prefix] = $prefix; $this->query('ATTACH DATABASE :database AS :prefix', array(':database' => $connection_options['database'] . '-' . $prefix, ':prefix' => $prefix)); } // Add a ., so queries become prefix.table, which is proper syntax for // querying an attached database. $prefix .= '.'; } } // Regenerate the prefixes replacement table. $this->setPrefix($prefixes); // Detect support for SAVEPOINT. $version = $this->query('SELECT sqlite_version()')->fetchField(); $this->savepointSupport = (version_compare($version, '3.6.8') >= 0); // Create functions needed by SQLite. $this->sqliteCreateFunction('if', array($this, 'sqlFunctionIf')); $this->sqliteCreateFunction('greatest', array($this, 'sqlFunctionGreatest')); $this->sqliteCreateFunction('pow', 'pow', 2); $this->sqliteCreateFunction('length', 'strlen', 1); $this->sqliteCreateFunction('md5', 'md5', 1); $this->sqliteCreateFunction('concat', array($this, 'sqlFunctionConcat')); $this->sqliteCreateFunction('substring', array($this, 'sqlFunctionSubstring'), 3); $this->sqliteCreateFunction('substring_index', array($this, 'sqlFunctionSubstringIndex'), 3); $this->sqliteCreateFunction('rand', array($this, 'sqlFunctionRand')); // Enable the Write-Ahead Logging (WAL) option for SQLite if supported. // @see https://www.drupal.org/node/2348137 // @see https://sqlite.org/wal.html if (version_compare($version, '3.7') >= 0) { $connection_options += array( 'init_commands' => array(), ); $connection_options['init_commands'] += array( 'wal' => "PRAGMA journal_mode=WAL", ); } // Execute sqlite init_commands. if (isset($connection_options['init_commands'])) { $this->connection->exec(implode('; ', $connection_options['init_commands'])); } } /** * Destructor for the SQLite connection. * * We prune empty databases on destruct, but only if tables have been * dropped. This is especially needed when running the test suite, which * creates and destroy databases several times in a row. */ public function __destruct() { if ($this->tableDropped && !empty($this->attachedDatabases)) { foreach ($this->attachedDatabases as $prefix) { // Check if the database is now empty, ignore the internal SQLite tables. try { $count = $this->query('SELECT COUNT(*) FROM ' . $prefix . '.sqlite_master WHERE type = :type AND name NOT LIKE :pattern', array(':type' => 'table', ':pattern' => 'sqlite_%'))->fetchField(); // We can prune the database file if it doesn't have any tables. if ($count == 0 && $this->connectionOptions['database'] != ':memory:') { // Detaching the database fails at this point, but no other queries // are executed after the connection is destructed so we can simply // remove the database file. unlink($this->connectionOptions['database'] . '-' . $prefix); } } catch (Exception $e) { // Ignore the exception and continue. There is nothing we can do here // to report the error or fail safe. } } } } /** * Gets all the attached databases. * * @return array * An array of attached database names. * * @see DatabaseConnection_sqlite::__construct(). */ public function getAttachedDatabases() { return $this->attachedDatabases; } /** * SQLite compatibility implementation for the IF() SQL function. */ public function sqlFunctionIf($condition, $expr1, $expr2 = NULL) { return $condition ? $expr1 : $expr2; } /** * SQLite compatibility implementation for the GREATEST() SQL function. */ public function sqlFunctionGreatest() { $args = func_get_args(); foreach ($args as $k => $v) { if (!isset($v)) { unset($args); } } if (count($args)) { return max($args); } else { return NULL; } } /** * SQLite compatibility implementation for the CONCAT() SQL function. */ public function sqlFunctionConcat() { $args = func_get_args(); return implode('', $args); } /** * SQLite compatibility implementation for the SUBSTRING() SQL function. */ public function sqlFunctionSubstring($string, $from, $length) { return substr($string, $from - 1, $length); } /** * SQLite compatibility implementation for the SUBSTRING_INDEX() SQL function. */ public function sqlFunctionSubstringIndex($string, $delimiter, $count) { // If string is empty, simply return an empty string. if (empty($string)) { return ''; } $end = 0; for ($i = 0; $i < $count; $i++) { $end = strpos($string, $delimiter, $end + 1); if ($end === FALSE) { $end = strlen($string); } } return substr($string, 0, $end); } /** * SQLite compatibility implementation for the RAND() SQL function. */ public function sqlFunctionRand($seed = NULL) { if (isset($seed)) { mt_srand($seed); } return mt_rand() / mt_getrandmax(); } /** * SQLite-specific implementation of DatabaseConnection::prepare(). * * We don't use prepared statements at all at this stage. We just create * a DatabaseStatement_sqlite object, that will create a PDOStatement * using the semi-private PDOPrepare() method below. */ public function prepare($query, $options = array()) { return new DatabaseStatement_sqlite($this, $query, $options); } /** * NEVER CALL THIS FUNCTION: YOU MIGHT DEADLOCK YOUR PHP PROCESS. * * This is a wrapper around the parent PDO::prepare method. However, as * the PDO SQLite driver only closes SELECT statements when the PDOStatement * destructor is called and SQLite does not allow data change (INSERT, * UPDATE etc) on a table which has open SELECT statements, you should never * call this function and keep a PDOStatement object alive as that can lead * to a deadlock. This really, really should be private, but as * DatabaseStatement_sqlite needs to call it, we have no other choice but to * expose this function to the world. */ public function PDOPrepare($query, array $options = array()) { return $this->connection->prepare($query, $options); } public function queryRange($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()) { // Generate a new temporary table name and protect it from prefixing. // SQLite requires that temporary tables to be non-qualified. $tablename = $this->generateTemporaryTableName(); $prefixes = $this->prefixes; $prefixes[$tablename] = ''; $this->setPrefix($prefixes); $this->query('CREATE TEMPORARY TABLE ' . $tablename . ' AS ' . $query, $args, $options); return $tablename; } public function driver() { return 'sqlite'; } public function databaseType() { return 'sqlite'; } public function mapConditionOperator($operator) { // We don't want to override any of the defaults. static $specials = array( 'LIKE' => array('postfix' => " ESCAPE '\\'"), 'NOT LIKE' => array('postfix' => " ESCAPE '\\'"), ); return isset($specials[$operator]) ? $specials[$operator] : NULL; } public function prepareQuery($query) { return $this->prepare($this->prefixTables($query)); } public function nextId($existing_id = 0) { $transaction = $this->startTransaction(); // We can safely use literal queries here instead of the slower query // builder because if a given database breaks here then it can simply // override nextId. However, this is unlikely as we deal with short strings // and integers and no known databases require special handling for those // simple cases. If another transaction wants to write the same row, it will // wait until this transaction commits. $stmt = $this->query('UPDATE {sequences} SET value = GREATEST(value, :existing_id) + 1', array( ':existing_id' => $existing_id, )); if (!$stmt->rowCount()) { $this->query('INSERT INTO {sequences} (value) VALUES (:existing_id + 1)', array( ':existing_id' => $existing_id, )); } // The transaction gets committed when the transaction object gets destroyed // because it gets out of scope. return $this->query('SELECT value FROM {sequences}')->fetchField(); } public function rollback($savepoint_name = 'drupal_transaction') { if ($this->savepointSupport) { return parent::rollBack($savepoint_name); } if (!$this->inTransaction()) { throw new DatabaseTransactionNoActiveException(); } // A previous rollback to an earlier savepoint may mean that the savepoint // in question has already been rolled back. if (!in_array($savepoint_name, $this->transactionLayers)) { return; } // We need to find the point we're rolling back to, all other savepoints // before are no longer needed. while ($savepoint = array_pop($this->transactionLayers)) { if ($savepoint == $savepoint_name) { // Mark whole stack of transactions as needed roll back. $this->willRollback = TRUE; // If it is the last the transaction in the stack, then it is not a // savepoint, it is the transaction itself so we will need to roll back // the transaction rather than a savepoint. if (empty($this->transactionLayers)) { break; } return; } } if ($this->supportsTransactions()) { $this->connection->rollBack(); } } public function pushTransaction($name) { if ($this->savepointSupport) { return parent::pushTransaction($name); } if (!$this->supportsTransactions()) { return; } if (isset($this->transactionLayers[$name])) { throw new DatabaseTransactionNameNonUniqueException($name . " is already in use."); } if (!$this->inTransaction()) { $this->connection->beginTransaction(); } $this->transactionLayers[$name] = $name; } public function popTransaction($name) { if ($this->savepointSupport) { return parent::popTransaction($name); } if (!$this->supportsTransactions()) { return; } if (!$this->inTransaction()) { throw new DatabaseTransactionNoActiveException(); } // Commit everything since SAVEPOINT $name. while($savepoint = array_pop($this->transactionLayers)) { if ($savepoint != $name) continue; // If there are no more layers left then we should commit or rollback. if (empty($this->transactionLayers)) { // If there was any rollback() we should roll back whole transaction. if ($this->willRollback) { $this->willRollback = FALSE; $this->connection->rollBack(); } elseif (!$this->connection->commit()) { throw new DatabaseTransactionCommitFailedException(); } } else { break; } } } public function utf8mb4IsActive() { return TRUE; } public function utf8mb4IsSupported() { return TRUE; } } /** * Specific SQLite implementation of DatabaseConnection. * * See DatabaseConnection_sqlite::PDOPrepare() for reasons why we must prefetch * the data instead of using PDOStatement. * * @see DatabaseConnection_sqlite::PDOPrepare() */ class DatabaseStatement_sqlite extends DatabaseStatementPrefetch implements Iterator, DatabaseStatementInterface { /** * SQLite specific implementation of getStatement(). * * The PDO SQLite layer doesn't replace numeric placeholders in queries * correctly, and this makes numeric expressions (such as COUNT(*) >= :count) * fail. We replace numeric placeholders in the query ourselves to work * around this bug. * * See http://bugs.php.net/bug.php?id=45259 for more details. */ protected function getStatement($query, &$args = array()) { if (count($args)) { // Check if $args is a simple numeric array. if (range(0, count($args) - 1) === array_keys($args)) { // In that case, we have unnamed placeholders. $count = 0; $new_args = array(); foreach ($args as $value) { if (is_float($value) || is_int($value)) { if (is_float($value)) { // Force the conversion to float so as not to loose precision // in the automatic cast. $value = sprintf('%F', $value); } $query = substr_replace($query, $value, strpos($query, '?'), 1); } else { $placeholder = ':db_statement_placeholder_' . $count++; $query = substr_replace($query, $placeholder, strpos($query, '?'), 1); $new_args[$placeholder] = $value; } } $args = $new_args; } else { // Else, this is using named placeholders. foreach ($args as $placeholder => $value) { if (is_float($value) || is_int($value)) { if (is_float($value)) { // Force the conversion to float so as not to loose precision // in the automatic cast. $value = sprintf('%F', $value); } // We will remove this placeholder from the query as PDO throws an // exception if the number of placeholders in the query and the // arguments does not match. unset($args[$placeholder]); // PDO allows placeholders to not be prefixed by a colon. See // http://marc.info/?l=php-internals&m=111234321827149&w=2 for // more. if ($placeholder[0] != ':') { $placeholder = ":$placeholder"; } // When replacing the placeholders, make sure we search for the // exact placeholder. For example, if searching for // ':db_placeholder_1', do not replace ':db_placeholder_11'. $query = preg_replace('/' . preg_quote($placeholder) . '\b/', $value, $query); } } } } return $this->dbh->PDOPrepare($query); } public function execute($args = array(), $options = array()) { try { $return = parent::execute($args, $options); } catch (PDOException $e) { if (!empty($e->errorInfo[1]) && $e->errorInfo[1] === 17) { // The schema has changed. SQLite specifies that we must resend the query. $return = parent::execute($args, $options); } else { // Rethrow the exception. throw $e; } } // In some weird cases, SQLite will prefix some column names by the name // of the table. We post-process the data, by renaming the column names // using the same convention as MySQL and PostgreSQL. $rename_columns = array(); foreach ($this->columnNames as $k => $column) { // In some SQLite versions, SELECT DISTINCT(field) will return "(field)" // instead of "field". if (preg_match("/^\((.*)\)$/", $column, $matches)) { $rename_columns[$column] = $matches[1]; $this->columnNames[$k] = $matches[1]; $column = $matches[1]; } // Remove "table." prefixes. if (preg_match("/^.*\.(.*)$/", $column, $matches)) { $rename_columns[$column] = $matches[1]; $this->columnNames[$k] = $matches[1]; } } if ($rename_columns) { // DatabaseStatementPrefetch already extracted the first row, // put it back into the result set. if (isset($this->currentRow)) { $this->data[0] = &$this->currentRow; } // Then rename all the columns across the result set. foreach ($this->data as $k => $row) { foreach ($rename_columns as $old_column => $new_column) { $this->data[$k][$new_column] = $this->data[$k][$old_column]; unset($this->data[$k][$old_column]); } } // Finally, extract the first row again. $this->currentRow = $this->data[0]; unset($this->data[0]); } return $return; } } /** * @} End of "addtogroup database". */