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+<?php
+
+/**
+ * @file
+ * Core systems for the database layer.
+ *
+ * Classes required for basic functioning of the database system should be
+ * placed in this file. All utility functions should also be placed in this
+ * file only, as they cannot auto-load the way classes can.
+ */
+
+/**
+ * @defgroup database Database abstraction layer
+ * @{
+ * Allow the use of different database servers using the same code base.
+ *
+ * Drupal provides a database abstraction layer to provide developers with
+ * the ability to support multiple database servers easily. The intent of
+ * this layer is to preserve the syntax and power of SQL as much as possible,
+ * but also allow developers a way to leverage more complex functionality in
+ * a unified way. It also provides a structured interface for dynamically
+ * constructing queries when appropriate, and enforcing security checks and
+ * similar good practices.
+ *
+ * The system is built atop PHP's PDO (PHP Data Objects) database API and
+ * inherits much of its syntax and semantics.
+ *
+ * Most Drupal database SELECT queries are performed by a call to db_query() or
+ * db_query_range(). Module authors should also consider using the PagerDefault
+ * Extender for queries that return results that need to be presented on
+ * multiple pages, and the Tablesort Extender for generating appropriate queries
+ * for sortable tables.
+ *
+ * For example, one might wish to return a list of the most recent 10 nodes
+ * authored by a given user. Instead of directly issuing the SQL query
+ * @code
+ * SELECT n.nid, n.title, n.created FROM node n WHERE n.uid = $uid LIMIT 0, 10;
+ * @endcode
+ * one would instead call the Drupal functions:
+ * @code
+ * $result = db_query_range('SELECT n.nid, n.title, n.created
+ * FROM {node} n WHERE n.uid = :uid', 0, 10, array(':uid' => $uid));
+ * foreach ($result as $record) {
+ * // Perform operations on $record->title, etc. here.
+ * }
+ * @endcode
+ * Curly braces are used around "node" to provide table prefixing via
+ * DatabaseConnection::prefixTables(). The explicit use of a user ID is pulled
+ * out into an argument passed to db_query() so that SQL injection attacks
+ * from user input can be caught and nullified. The LIMIT syntax varies between
+ * database servers, so that is abstracted into db_query_range() arguments.
+ * Finally, note the PDO-based ability to iterate over the result set using
+ * foreach ().
+ *
+ * All queries are passed as a prepared statement string. A
+ * prepared statement is a "template" of a query that omits literal or variable
+ * values in favor of placeholders. The values to place into those
+ * placeholders are passed separately, and the database driver handles
+ * inserting the values into the query in a secure fashion. That means you
+ * should never quote or string-escape a value to be inserted into the query.
+ *
+ * There are two formats for placeholders: named and unnamed. Named placeholders
+ * are strongly preferred in all cases as they are more flexible and
+ * self-documenting. Named placeholders should start with a colon ":" and can be
+ * followed by one or more letters, numbers or underscores.
+ *
+ * Named placeholders begin with a colon followed by a unique string. Example:
+ * @code
+ * SELECT nid, title FROM {node} WHERE uid=:uid;
+ * @endcode
+ *
+ * ":uid" is a placeholder that will be replaced with a literal value when
+ * the query is executed. A given placeholder label cannot be repeated in a
+ * given query, even if the value should be the same. When using named
+ * placeholders, the array of arguments to the query must be an associative
+ * array where keys are a placeholder label (e.g., :uid) and the value is the
+ * corresponding value to use. The array may be in any order.
+ *
+ * Unnamed placeholders are simply a question mark. Example:
+ * @code
+ * SELECT nid, title FROM {node} WHERE uid=?;
+ * @endcode
+ *
+ * In this case, the array of arguments must be an indexed array of values to
+ * use in the exact same order as the placeholders in the query.
+ *
+ * Note that placeholders should be a "complete" value. For example, when
+ * running a LIKE query the SQL wildcard character, %, should be part of the
+ * value, not the query itself. Thus, the following is incorrect:
+ * @code
+ * SELECT nid, title FROM {node} WHERE title LIKE :title%;
+ * @endcode
+ * It should instead read:
+ * @code
+ * SELECT nid, title FROM {node} WHERE title LIKE :title;
+ * @endcode
+ * and the value for :title should include a % as appropriate. Again, note the
+ * lack of quotation marks around :title. Because the value is not inserted
+ * into the query as one big string but as an explicitly separate value, the
+ * database server knows where the query ends and a value begins. That is
+ * considerably more secure against SQL injection than trying to remember
+ * which values need quotation marks and string escaping and which don't.
+ *
+ * INSERT, UPDATE, and DELETE queries need special care in order to behave
+ * consistently across all different databases. Therefore, they use a special
+ * object-oriented API for defining a query structurally. For example, rather
+ * than:
+ * @code
+ * INSERT INTO node (nid, title, body) VALUES (1, 'my title', 'my body');
+ * @endcode
+ * one would instead write:
+ * @code
+ * $fields = array('nid' => 1, 'title' => 'my title', 'body' => 'my body');
+ * db_insert('node')->fields($fields)->execute();
+ * @endcode
+ * This method allows databases that need special data type handling to do so,
+ * while also allowing optimizations such as multi-insert queries. UPDATE and
+ * DELETE queries have a similar pattern.
+ *
+ * Drupal also supports transactions, including a transparent fallback for
+ * databases that do not support transactions. To start a new transaction,
+ * simply call $txn = db_transaction(); in your own code. The transaction will
+ * remain open for as long as the variable $txn remains in scope. When $txn is
+ * destroyed, the transaction will be committed. If your transaction is nested
+ * inside of another then Drupal will track each transaction and only commit
+ * the outer-most transaction when the last transaction object goes out out of
+ * scope, that is, all relevant queries completed successfully.
+ *
+ * Example:
+ * @code
+ * function my_transaction_function() {
+ * // The transaction opens here.
+ * $txn = db_transaction();
+ *
+ * try {
+ * $id = db_insert('example')
+ * ->fields(array(
+ * 'field1' => 'mystring',
+ * 'field2' => 5,
+ * ))
+ * ->execute();
+ *
+ * my_other_function($id);
+ *
+ * return $id;
+ * }
+ * catch (Exception $e) {
+ * // Something went wrong somewhere, so roll back now.
+ * $txn->rollback();
+ * // Log the exception to watchdog.
+ * watchdog_exception('type', $e);
+ * }
+ *
+ * // $txn goes out of scope here. Unless the transaction was rolled back, it
+ * // gets automatically committed here.
+ * }
+ *
+ * function my_other_function($id) {
+ * // The transaction is still open here.
+ *
+ * if ($id % 2 == 0) {
+ * db_update('example')
+ * ->condition('id', $id)
+ * ->fields(array('field2' => 10))
+ * ->execute();
+ * }
+ * }
+ * @endcode
+ *
+ * @see http://drupal.org/developing/api/database
+ */
+
+
+/**
+ * Base Database API class.
+ *
+ * This class provides a Drupal-specific extension of the PDO database
+ * abstraction class in PHP. Every database driver implementation must provide a
+ * concrete implementation of it to support special handling required by that
+ * database.
+ *
+ * @see http://php.net/manual/book.pdo.php
+ */
+abstract class DatabaseConnection extends PDO {
+
+ /**
+ * The database target this connection is for.
+ *
+ * We need this information for later auditing and logging.
+ *
+ * @var string
+ */
+ protected $target = NULL;
+
+ /**
+ * The key representing this connection.
+ *
+ * The key is a unique string which identifies a database connection. A
+ * connection can be a single server or a cluster of master and slaves (use
+ * target to pick between master and slave).
+ *
+ * @var string
+ */
+ protected $key = NULL;
+
+ /**
+ * The current database logging object for this connection.
+ *
+ * @var DatabaseLog
+ */
+ protected $logger = NULL;
+
+ /**
+ * Tracks the number of "layers" of transactions currently active.
+ *
+ * On many databases transactions cannot nest. Instead, we track
+ * nested calls to transactions and collapse them into a single
+ * transaction.
+ *
+ * @var array
+ */
+ protected $transactionLayers = array();
+
+ /**
+ * Index of what driver-specific class to use for various operations.
+ *
+ * @var array
+ */
+ protected $driverClasses = array();
+
+ /**
+ * The name of the Statement class for this connection.
+ *
+ * @var string
+ */
+ protected $statementClass = 'DatabaseStatementBase';
+
+ /**
+ * Whether this database connection supports transactions.
+ *
+ * @var bool
+ */
+ protected $transactionSupport = TRUE;
+
+ /**
+ * Whether this database connection supports transactional DDL.
+ *
+ * Set to FALSE by default because few databases support this feature.
+ *
+ * @var bool
+ */
+ protected $transactionalDDLSupport = FALSE;
+
+ /**
+ * An index used to generate unique temporary table names.
+ *
+ * @var integer
+ */
+ protected $temporaryNameIndex = 0;
+
+ /**
+ * The connection information for this connection object.
+ *
+ * @var array
+ */
+ protected $connectionOptions = array();
+
+ /**
+ * The schema object for this connection.
+ *
+ * @var object
+ */
+ protected $schema = NULL;
+
+ /**
+ * The prefixes used by this database connection.
+ *
+ * @var array
+ */
+ protected $prefixes = array();
+
+ /**
+ * List of search values for use in prefixTables().
+ *
+ * @var array
+ */
+ protected $prefixSearch = array();
+
+ /**
+ * List of replacement values for use in prefixTables().
+ *
+ * @var array
+ */
+ protected $prefixReplace = array();
+
+ function __construct($dsn, $username, $password, $driver_options = array()) {
+ // Initialize and prepare the connection prefix.
+ $this->setPrefix(isset($this->connectionOptions['prefix']) ? $this->connectionOptions['prefix'] : '');
+
+ // Because the other methods don't seem to work right.
+ $driver_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
+
+ // Call PDO::__construct and PDO::setAttribute.
+ parent::__construct($dsn, $username, $password, $driver_options);
+
+ // Set a Statement class, unless the driver opted out.
+ if (!empty($this->statementClass)) {
+ $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array($this->statementClass, array($this)));
+ }
+ }
+
+ /**
+ * Destroys this Connection object.
+ *
+ * PHP does not destruct an object if it is still referenced in other
+ * variables. In case of PDO database connection objects, PHP only closes the
+ * connection when the PDO object is destructed, so any references to this
+ * object may cause the number of maximum allowed connections to be exceeded.
+ */
+ public function destroy() {
+ // Destroy all references to this connection by setting them to NULL.
+ // The Statement class attribute only accepts a new value that presents a
+ // proper callable, so we reset it to PDOStatement.
+ $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array('PDOStatement', array()));
+ $this->schema = NULL;
+ }
+
+ /**
+ * Returns the default query options for any given query.
+ *
+ * A given query can be customized with a number of option flags in an
+ * associative array:
+ * - target: The database "target" against which to execute a query. Valid
+ * values are "default" or "slave". The system will first try to open a
+ * connection to a database specified with the user-supplied key. If one
+ * is not available, it will silently fall back to the "default" target.
+ * If multiple databases connections are specified with the same target,
+ * one will be selected at random for the duration of the request.
+ * - fetch: This element controls how rows from a result set will be
+ * returned. Legal values include PDO::FETCH_ASSOC, PDO::FETCH_BOTH,
+ * PDO::FETCH_OBJ, PDO::FETCH_NUM, or a string representing the name of a
+ * class. If a string is specified, each record will be fetched into a new
+ * object of that class. The behavior of all other values is defined by PDO.
+ * See http://php.net/manual/pdostatement.fetch.php
+ * - return: Depending on the type of query, different return values may be
+ * meaningful. This directive instructs the system which type of return
+ * value is desired. The system will generally set the correct value
+ * automatically, so it is extremely rare that a module developer will ever
+ * need to specify this value. Setting it incorrectly will likely lead to
+ * unpredictable results or fatal errors. Legal values include:
+ * - Database::RETURN_STATEMENT: Return the prepared statement object for
+ * the query. This is usually only meaningful for SELECT queries, where
+ * the statement object is how one accesses the result set returned by the
+ * query.
+ * - Database::RETURN_AFFECTED: Return the number of rows affected by an
+ * UPDATE or DELETE query. Be aware that means the number of rows actually
+ * changed, not the number of rows matched by the WHERE clause.
+ * - Database::RETURN_INSERT_ID: Return the sequence ID (primary key)
+ * created by an INSERT statement on a table that contains a serial
+ * column.
+ * - Database::RETURN_NULL: Do not return anything, as there is no
+ * meaningful value to return. That is the case for INSERT queries on
+ * tables that do not contain a serial column.
+ * - throw_exception: By default, the database system will catch any errors
+ * on a query as an Exception, log it, and then rethrow it so that code
+ * further up the call chain can take an appropriate action. To suppress
+ * that behavior and simply return NULL on failure, set this option to
+ * FALSE.
+ *
+ * @return
+ * An array of default query options.
+ */
+ protected function defaultOptions() {
+ return array(
+ 'target' => 'default',
+ 'fetch' => PDO::FETCH_OBJ,
+ 'return' => Database::RETURN_STATEMENT,
+ 'throw_exception' => TRUE,
+ );
+ }
+
+ /**
+ * Returns the connection information for this connection object.
+ *
+ * Note that Database::getConnectionInfo() is for requesting information
+ * about an arbitrary database connection that is defined. This method
+ * is for requesting the connection information of this specific
+ * open connection object.
+ *
+ * @return
+ * An array of the connection information. The exact list of
+ * properties is driver-dependent.
+ */
+ public function getConnectionOptions() {
+ return $this->connectionOptions;
+ }
+
+ /**
+ * Set the list of prefixes used by this database connection.
+ *
+ * @param $prefix
+ * The prefixes, in any of the multiple forms documented in
+ * default.settings.php.
+ */
+ protected function setPrefix($prefix) {
+ if (is_array($prefix)) {
+ $this->prefixes = $prefix + array('default' => '');
+ }
+ else {
+ $this->prefixes = array('default' => $prefix);
+ }
+
+ // Set up variables for use in prefixTables(). Replace table-specific
+ // prefixes first.
+ $this->prefixSearch = array();
+ $this->prefixReplace = array();
+ foreach ($this->prefixes as $key => $val) {
+ if ($key != 'default') {
+ $this->prefixSearch[] = '{' . $key . '}';
+ $this->prefixReplace[] = $val . $key;
+ }
+ }
+ // Then replace remaining tables with the default prefix.
+ $this->prefixSearch[] = '{';
+ $this->prefixReplace[] = $this->prefixes['default'];
+ $this->prefixSearch[] = '}';
+ $this->prefixReplace[] = '';
+ }
+
+ /**
+ * Appends a database prefix to all tables in a query.
+ *
+ * Queries sent to Drupal should wrap all table names in curly brackets. This
+ * function searches for this syntax and adds Drupal's table prefix to all
+ * tables, allowing Drupal to coexist with other systems in the same database
+ * and/or schema if necessary.
+ *
+ * @param $sql
+ * A string containing a partial or entire SQL query.
+ *
+ * @return
+ * The properly-prefixed string.
+ */
+ public function prefixTables($sql) {
+ return str_replace($this->prefixSearch, $this->prefixReplace, $sql);
+ }
+
+ /**
+ * Find the prefix for a table.
+ *
+ * This function is for when you want to know the prefix of a table. This
+ * is not used in prefixTables due to performance reasons.
+ */
+ public function tablePrefix($table = 'default') {
+ if (isset($this->prefixes[$table])) {
+ return $this->prefixes[$table];
+ }
+ else {
+ return $this->prefixes['default'];
+ }
+ }
+
+ /**
+ * Prepares a query string and returns the prepared statement.
+ *
+ * This method caches prepared statements, reusing them when
+ * possible. It also prefixes tables names enclosed in curly-braces.
+ *
+ * @param $query
+ * The query string as SQL, with curly-braces surrounding the
+ * table names.
+ *
+ * @return DatabaseStatementInterface
+ * A PDO prepared statement ready for its execute() method.
+ */
+ public function prepareQuery($query) {
+ $query = $this->prefixTables($query);
+
+ // Call PDO::prepare.
+ return parent::prepare($query);
+ }
+
+ /**
+ * Tells this connection object what its target value is.
+ *
+ * This is needed for logging and auditing. It's sloppy to do in the
+ * constructor because the constructor for child classes has a different
+ * signature. We therefore also ensure that this function is only ever
+ * called once.
+ *
+ * @param $target
+ * The target this connection is for. Set to NULL (default) to disable
+ * logging entirely.
+ */
+ public function setTarget($target = NULL) {
+ if (!isset($this->target)) {
+ $this->target = $target;
+ }
+ }
+
+ /**
+ * Returns the target this connection is associated with.
+ *
+ * @return
+ * The target string of this connection.
+ */
+ public function getTarget() {
+ return $this->target;
+ }
+
+ /**
+ * Tells this connection object what its key is.
+ *
+ * @param $target
+ * The key this connection is for.
+ */
+ public function setKey($key) {
+ if (!isset($this->key)) {
+ $this->key = $key;
+ }
+ }
+
+ /**
+ * Returns the key this connection is associated with.
+ *
+ * @return
+ * The key of this connection.
+ */
+ public function getKey() {
+ return $this->key;
+ }
+
+ /**
+ * Associates a logging object with this connection.
+ *
+ * @param $logger
+ * The logging object we want to use.
+ */
+ public function setLogger(DatabaseLog $logger) {
+ $this->logger = $logger;
+ }
+
+ /**
+ * Gets the current logging object for this connection.
+ *
+ * @return DatabaseLog
+ * The current logging object for this connection. If there isn't one,
+ * NULL is returned.
+ */
+ public function getLogger() {
+ return $this->logger;
+ }
+
+ /**
+ * Creates the appropriate sequence name for a given table and serial field.
+ *
+ * This information is exposed to all database drivers, although it is only
+ * useful on some of them. This method is table prefix-aware.
+ *
+ * @param $table
+ * The table name to use for the sequence.
+ * @param $field
+ * The field name to use for the sequence.
+ *
+ * @return
+ * A table prefix-parsed string for the sequence name.
+ */
+ public function makeSequenceName($table, $field) {
+ return $this->prefixTables('{' . $table . '}_' . $field . '_seq');
+ }
+
+ /**
+ * Flatten an array of query comments into a single comment string.
+ *
+ * The comment string will be sanitized to avoid SQL injection attacks.
+ *
+ * @param $comments
+ * An array of query comment strings.
+ *
+ * @return
+ * A sanitized comment string.
+ */
+ public function makeComment($comments) {
+ if (empty($comments))
+ return '';
+
+ // Flatten the array of comments.
+ $comment = implode('; ', $comments);
+
+ // Sanitize the comment string so as to avoid SQL injection attacks.
+ return '/* ' . $this->filterComment($comment) . ' */ ';
+ }
+
+ /**
+ * Sanitize a query comment string.
+ *
+ * Ensure a query comment does not include strings such as "* /" that might
+ * terminate the comment early. This avoids SQL injection attacks via the
+ * query comment. The comment strings in this example are separated by a
+ * space to avoid PHP parse errors.
+ *
+ * For example, the comment:
+ * @code
+ * db_update('example')
+ * ->condition('id', $id)
+ * ->fields(array('field2' => 10))
+ * ->comment('Exploit * / DROP TABLE node; --')
+ * ->execute()
+ * @endcode
+ *
+ * Would result in the following SQL statement being generated:
+ * @code
+ * "/ * Exploit * / DROP TABLE node; -- * / UPDATE example SET field2=..."
+ * @endcode
+ *
+ * Unless the comment is sanitised first, the SQL server would drop the
+ * node table and ignore the rest of the SQL statement.
+ *
+ * @param $comment
+ * A query comment string.
+ *
+ * @return
+ * A sanitized version of the query comment string.
+ */
+ protected function filterComment($comment = '') {
+ return preg_replace('/(\/\*\s*)|(\s*\*\/)/', '', $comment);
+ }
+
+ /**
+ * Executes a query string against the database.
+ *
+ * This method provides a central handler for the actual execution of every
+ * query. All queries executed by Drupal are executed as PDO prepared
+ * statements.
+ *
+ * @param $query
+ * The query to execute. In most cases this will be a string containing
+ * an SQL query with placeholders. An already-prepared instance of
+ * DatabaseStatementInterface may also be passed in order to allow calling
+ * code to manually bind variables to a query. If a
+ * DatabaseStatementInterface is passed, the $args array will be ignored.
+ * It is extremely rare that module code will need to pass a statement
+ * object to this method. It is used primarily for database drivers for
+ * databases that require special LOB field handling.
+ * @param $args
+ * An array of arguments for the prepared statement. If the prepared
+ * statement uses ? placeholders, this array must be an indexed array.
+ * If it contains named placeholders, it must be an associative array.
+ * @param $options
+ * An associative array of options to control how the query is run. See
+ * the documentation for DatabaseConnection::defaultOptions() for details.
+ *
+ * @return DatabaseStatementInterface
+ * This method will return one of: the executed statement, the number of
+ * rows affected by the query (not the number matched), or the generated
+ * insert IT of the last query, depending on the value of
+ * $options['return']. Typically that value will be set by default or a
+ * query builder and should not be set by a user. If there is an error,
+ * this method will return NULL and may throw an exception if
+ * $options['throw_exception'] is TRUE.
+ *
+ * @throws PDOException
+ */
+ public function query($query, array $args = array(), $options = array()) {
+
+ // Use default values if not already set.
+ $options += $this->defaultOptions();
+
+ try {
+ // We allow either a pre-bound statement object or a literal string.
+ // In either case, we want to end up with an executed statement object,
+ // which we pass to PDOStatement::execute.
+ if ($query instanceof DatabaseStatementInterface) {
+ $stmt = $query;
+ $stmt->execute(NULL, $options);
+ }
+ else {
+ $this->expandArguments($query, $args);
+ $stmt = $this->prepareQuery($query);
+ $stmt->execute($args, $options);
+ }
+
+ // Depending on the type of query we may need to return a different value.
+ // See DatabaseConnection::defaultOptions() for a description of each
+ // value.
+ switch ($options['return']) {
+ case Database::RETURN_STATEMENT:
+ return $stmt;
+ case Database::RETURN_AFFECTED:
+ return $stmt->rowCount();
+ case Database::RETURN_INSERT_ID:
+ return $this->lastInsertId();
+ case Database::RETURN_NULL:
+ return;
+ default:
+ throw new PDOException('Invalid return directive: ' . $options['return']);
+ }
+ }
+ catch (PDOException $e) {
+ if ($options['throw_exception']) {
+ // Add additional debug information.
+ if ($query instanceof DatabaseStatementInterface) {
+ $e->query_string = $stmt->getQueryString();
+ }
+ else {
+ $e->query_string = $query;
+ }
+ $e->args = $args;
+ throw $e;
+ }
+ return NULL;
+ }
+ }
+
+ /**
+ * Expands out shorthand placeholders.
+ *
+ * Drupal supports an alternate syntax for doing arrays of values. We
+ * therefore need to expand them out into a full, executable query string.
+ *
+ * @param $query
+ * The query string to modify.
+ * @param $args
+ * The arguments for the query.
+ *
+ * @return
+ * TRUE if the query was modified, FALSE otherwise.
+ */
+ protected function expandArguments(&$query, &$args) {
+ $modified = FALSE;
+
+ // If the placeholder value to insert is an array, assume that we need
+ // to expand it out into a comma-delimited set of placeholders.
+ foreach (array_filter($args, 'is_array') as $key => $data) {
+ $new_keys = array();
+ foreach ($data as $i => $value) {
+ // This assumes that there are no other placeholders that use the same
+ // name. For example, if the array placeholder is defined as :example
+ // and there is already an :example_2 placeholder, this will generate
+ // a duplicate key. We do not account for that as the calling code
+ // is already broken if that happens.
+ $new_keys[$key . '_' . $i] = $value;
+ }
+
+ // Update the query with the new placeholders.
+ // preg_replace is necessary to ensure the replacement does not affect
+ // placeholders that start with the same exact text. For example, if the
+ // query contains the placeholders :foo and :foobar, and :foo has an
+ // array of values, using str_replace would affect both placeholders,
+ // but using the following preg_replace would only affect :foo because
+ // it is followed by a non-word character.
+ $query = preg_replace('#' . $key . '\b#', implode(', ', array_keys($new_keys)), $query);
+
+ // Update the args array with the new placeholders.
+ unset($args[$key]);
+ $args += $new_keys;
+
+ $modified = TRUE;
+ }
+
+ return $modified;
+ }
+
+ /**
+ * Gets the driver-specific override class if any for the specified class.
+ *
+ * @param string $class
+ * The class for which we want the potentially driver-specific class.
+ * @param array $files
+ * The name of the files in which the driver-specific class can be.
+ * @param $use_autoload
+ * If TRUE, attempt to load classes using PHP's autoload capability
+ * as well as the manual approach here.
+ * @return string
+ * The name of the class that should be used for this driver.
+ */
+ public function getDriverClass($class, array $files = array(), $use_autoload = FALSE) {
+ if (empty($this->driverClasses[$class])) {
+ $driver = $this->driver();
+ $this->driverClasses[$class] = $class . '_' . $driver;
+ Database::loadDriverFile($driver, $files);
+ if (!class_exists($this->driverClasses[$class], $use_autoload)) {
+ $this->driverClasses[$class] = $class;
+ }
+ }
+ return $this->driverClasses[$class];
+ }
+
+ /**
+ * Prepares and returns a SELECT query object.
+ *
+ * @param $table
+ * The base table for this query, that is, the first table in the FROM
+ * clause. This table will also be used as the "base" table for query_alter
+ * hook implementations.
+ * @param $alias
+ * The alias of the base table of this query.
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return SelectQueryInterface
+ * An appropriate SelectQuery object for this database connection. Note that
+ * it may be a driver-specific subclass of SelectQuery, depending on the
+ * driver.
+ *
+ * @see SelectQuery
+ */
+ public function select($table, $alias = NULL, array $options = array()) {
+ $class = $this->getDriverClass('SelectQuery', array('query.inc', 'select.inc'));
+ return new $class($table, $alias, $this, $options);
+ }
+
+ /**
+ * Prepares and returns an INSERT query object.
+ *
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return InsertQuery
+ * A new InsertQuery object.
+ *
+ * @see InsertQuery
+ */
+ public function insert($table, array $options = array()) {
+ $class = $this->getDriverClass('InsertQuery', array('query.inc'));
+ return new $class($this, $table, $options);
+ }
+
+ /**
+ * Prepares and returns a MERGE query object.
+ *
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return MergeQuery
+ * A new MergeQuery object.
+ *
+ * @see MergeQuery
+ */
+ public function merge($table, array $options = array()) {
+ $class = $this->getDriverClass('MergeQuery', array('query.inc'));
+ return new $class($this, $table, $options);
+ }
+
+
+ /**
+ * Prepares and returns an UPDATE query object.
+ *
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return UpdateQuery
+ * A new UpdateQuery object.
+ *
+ * @see UpdateQuery
+ */
+ public function update($table, array $options = array()) {
+ $class = $this->getDriverClass('UpdateQuery', array('query.inc'));
+ return new $class($this, $table, $options);
+ }
+
+ /**
+ * Prepares and returns a DELETE query object.
+ *
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return DeleteQuery
+ * A new DeleteQuery object.
+ *
+ * @see DeleteQuery
+ */
+ public function delete($table, array $options = array()) {
+ $class = $this->getDriverClass('DeleteQuery', array('query.inc'));
+ return new $class($this, $table, $options);
+ }
+
+ /**
+ * Prepares and returns a TRUNCATE query object.
+ *
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return TruncateQuery
+ * A new TruncateQuery object.
+ *
+ * @see TruncateQuery
+ */
+ public function truncate($table, array $options = array()) {
+ $class = $this->getDriverClass('TruncateQuery', array('query.inc'));
+ return new $class($this, $table, $options);
+ }
+
+ /**
+ * Returns a DatabaseSchema object for manipulating the schema.
+ *
+ * This method will lazy-load the appropriate schema library file.
+ *
+ * @return DatabaseSchema
+ * The DatabaseSchema object for this connection.
+ */
+ public function schema() {
+ if (empty($this->schema)) {
+ $class = $this->getDriverClass('DatabaseSchema', array('schema.inc'));
+ if (class_exists($class)) {
+ $this->schema = new $class($this);
+ }
+ }
+ return $this->schema;
+ }
+
+ /**
+ * Escapes a table name string.
+ *
+ * Force all table names to be strictly alphanumeric-plus-underscore.
+ * For some database drivers, it may also wrap the table name in
+ * database-specific escape characters.
+ *
+ * @return
+ * The sanitized table name string.
+ */
+ public function escapeTable($table) {
+ return preg_replace('/[^A-Za-z0-9_.]+/', '', $table);
+ }
+
+ /**
+ * Escapes a field name string.
+ *
+ * Force all field names to be strictly alphanumeric-plus-underscore.
+ * For some database drivers, it may also wrap the field name in
+ * database-specific escape characters.
+ *
+ * @return
+ * The sanitized field name string.
+ */
+ public function escapeField($field) {
+ return preg_replace('/[^A-Za-z0-9_.]+/', '', $field);
+ }
+
+ /**
+ * Escapes an alias name string.
+ *
+ * Force all alias names to be strictly alphanumeric-plus-underscore. In
+ * contrast to DatabaseConnection::escapeField() /
+ * DatabaseConnection::escapeTable(), this doesn't allow the period (".")
+ * because that is not allowed in aliases.
+ *
+ * @return
+ * The sanitized field name string.
+ */
+ public function escapeAlias($field) {
+ return preg_replace('/[^A-Za-z0-9_]+/', '', $field);
+ }
+
+ /**
+ * Escapes characters that work as wildcard characters in a LIKE pattern.
+ *
+ * The wildcard characters "%" and "_" as well as backslash are prefixed with
+ * a backslash. Use this to do a search for a verbatim string without any
+ * wildcard behavior.
+ *
+ * For example, the following does a case-insensitive query for all rows whose
+ * name starts with $prefix:
+ * @code
+ * $result = db_query(
+ * 'SELECT * FROM person WHERE name LIKE :pattern',
+ * array(':pattern' => db_like($prefix) . '%')
+ * );
+ * @endcode
+ *
+ * Backslash is defined as escape character for LIKE patterns in
+ * DatabaseCondition::mapConditionOperator().
+ *
+ * @param $string
+ * The string to escape.
+ *
+ * @return
+ * The escaped string.
+ */
+ public function escapeLike($string) {
+ return addcslashes($string, '\%_');
+ }
+
+ /**
+ * Determines if there is an active transaction open.
+ *
+ * @return
+ * TRUE if we're currently in a transaction, FALSE otherwise.
+ */
+ public function inTransaction() {
+ return ($this->transactionDepth() > 0);
+ }
+
+ /**
+ * Determines current transaction depth.
+ */
+ public function transactionDepth() {
+ return count($this->transactionLayers);
+ }
+
+ /**
+ * Returns a new DatabaseTransaction object on this connection.
+ *
+ * @param $name
+ * Optional name of the savepoint.
+ *
+ * @return DatabaseTransaction
+ * A DatabaseTransaction object.
+ *
+ * @see DatabaseTransaction
+ */
+ public function startTransaction($name = '') {
+ $class = $this->getDriverClass('DatabaseTransaction');
+ return new $class($this, $name);
+ }
+
+ /**
+ * Rolls back the transaction entirely or to a named savepoint.
+ *
+ * This method throws an exception if no transaction is active.
+ *
+ * @param $savepoint_name
+ * The name of the savepoint. The default, 'drupal_transaction', will roll
+ * the entire transaction back.
+ *
+ * @throws DatabaseTransactionNoActiveException
+ *
+ * @see DatabaseTransaction::rollback()
+ */
+ public function rollback($savepoint_name = 'drupal_transaction') {
+ if (!$this->supportsTransactions()) {
+ return;
+ }
+ if (!$this->inTransaction()) {
+ throw new DatabaseTransactionNoActiveException();
+ }
+ // A previous rollback to an earlier savepoint may mean that the savepoint
+ // in question has already been accidentally committed.
+ if (!isset($this->transactionLayers[$savepoint_name])) {
+ throw new DatabaseTransactionNoActiveException();
+ }
+
+ // We need to find the point we're rolling back to, all other savepoints
+ // before are no longer needed. If we rolled back other active savepoints,
+ // we need to throw an exception.
+ $rolled_back_other_active_savepoints = FALSE;
+ while ($savepoint = array_pop($this->transactionLayers)) {
+ if ($savepoint == $savepoint_name) {
+ // If it is the last the transaction in the stack, then it is not a
+ // savepoint, it is the transaction itself so we will need to roll back
+ // the transaction rather than a savepoint.
+ if (empty($this->transactionLayers)) {
+ break;
+ }
+ $this->query('ROLLBACK TO SAVEPOINT ' . $savepoint);
+ $this->popCommittableTransactions();
+ if ($rolled_back_other_active_savepoints) {
+ throw new DatabaseTransactionOutOfOrderException();
+ }
+ return;
+ }
+ else {
+ $rolled_back_other_active_savepoints = TRUE;
+ }
+ }
+ parent::rollBack();
+ if ($rolled_back_other_active_savepoints) {
+ throw new DatabaseTransactionOutOfOrderException();
+ }
+ }
+
+ /**
+ * Increases the depth of transaction nesting.
+ *
+ * If no transaction is already active, we begin a new transaction.
+ *
+ * @throws DatabaseTransactionNameNonUniqueException
+ *
+ * @see DatabaseTransaction
+ */
+ public function pushTransaction($name) {
+ if (!$this->supportsTransactions()) {
+ return;
+ }
+ if (isset($this->transactionLayers[$name])) {
+ throw new DatabaseTransactionNameNonUniqueException($name . " is already in use.");
+ }
+ // If we're already in a transaction then we want to create a savepoint
+ // rather than try to create another transaction.
+ if ($this->inTransaction()) {
+ $this->query('SAVEPOINT ' . $name);
+ }
+ else {
+ parent::beginTransaction();
+ }
+ $this->transactionLayers[$name] = $name;
+ }
+
+ /**
+ * Decreases the depth of transaction nesting.
+ *
+ * If we pop off the last transaction layer, then we either commit or roll
+ * back the transaction as necessary. If no transaction is active, we return
+ * because the transaction may have manually been rolled back.
+ *
+ * @param $name
+ * The name of the savepoint
+ *
+ * @throws DatabaseTransactionNoActiveException
+ * @throws DatabaseTransactionCommitFailedException
+ *
+ * @see DatabaseTransaction
+ */
+ public function popTransaction($name) {
+ if (!$this->supportsTransactions()) {
+ return;
+ }
+ // The transaction has already been committed earlier. There is nothing we
+ // need to do. If this transaction was part of an earlier out-of-order
+ // rollback, an exception would already have been thrown by
+ // Database::rollback().
+ if (!isset($this->transactionLayers[$name])) {
+ return;
+ }
+
+ // Mark this layer as committable.
+ $this->transactionLayers[$name] = FALSE;
+ $this->popCommittableTransactions();
+ }
+
+ /**
+ * Internal function: commit all the transaction layers that can commit.
+ */
+ protected function popCommittableTransactions() {
+ // Commit all the committable layers.
+ foreach (array_reverse($this->transactionLayers) as $name => $active) {
+ // Stop once we found an active transaction.
+ if ($active) {
+ break;
+ }
+
+ // If there are no more layers left then we should commit.
+ unset($this->transactionLayers[$name]);
+ if (empty($this->transactionLayers)) {
+ if (!parent::commit()) {
+ throw new DatabaseTransactionCommitFailedException();
+ }
+ }
+ else {
+ $this->query('RELEASE SAVEPOINT ' . $name);
+ }
+ }
+ }
+
+ /**
+ * Runs a limited-range query on this database object.
+ *
+ * Use this as a substitute for ->query() when a subset of the query is to be
+ * returned. User-supplied arguments to the query should be passed in as
+ * separate parameters so that they can be properly escaped to avoid SQL
+ * injection attacks.
+ *
+ * @param $query
+ * A string containing an SQL query.
+ * @param $args
+ * An array of values to substitute into the query at placeholder markers.
+ * @param $from
+ * The first result row to return.
+ * @param $count
+ * The maximum number of result rows to return.
+ * @param $options
+ * An array of options on the query.
+ *
+ * @return DatabaseStatementInterface
+ * A database query result resource, or NULL if the query was not executed
+ * correctly.
+ */
+ abstract public function queryRange($query, $from, $count, array $args = array(), array $options = array());
+
+ /**
+ * Generates a temporary table name.
+ *
+ * @return
+ * A table name.
+ */
+ protected function generateTemporaryTableName() {
+ return "db_temporary_" . $this->temporaryNameIndex++;
+ }
+
+ /**
+ * Runs a SELECT query and stores its results in a temporary table.
+ *
+ * Use this as a substitute for ->query() when the results need to stored
+ * in a temporary table. Temporary tables exist for the duration of the page
+ * request. User-supplied arguments to the query should be passed in as
+ * separate parameters so that they can be properly escaped to avoid SQL
+ * injection attacks.
+ *
+ * Note that if you need to know how many results were returned, you should do
+ * a SELECT COUNT(*) on the temporary table afterwards.
+ *
+ * @param $query
+ * A string containing a normal SELECT SQL query.
+ * @param $args
+ * An array of values to substitute into the query at placeholder markers.
+ * @param $options
+ * An associative array of options to control how the query is run. See
+ * the documentation for DatabaseConnection::defaultOptions() for details.
+ *
+ * @return
+ * The name of the temporary table.
+ */
+ abstract function queryTemporary($query, array $args = array(), array $options = array());
+
+ /**
+ * Returns the type of database driver.
+ *
+ * This is not necessarily the same as the type of the database itself. For
+ * instance, there could be two MySQL drivers, mysql and mysql_mock. This
+ * function would return different values for each, but both would return
+ * "mysql" for databaseType().
+ */
+ abstract public function driver();
+
+ /**
+ * Returns the version of the database server.
+ */
+ public function version() {
+ return $this->getAttribute(PDO::ATTR_SERVER_VERSION);
+ }
+
+ /**
+ * Determines if this driver supports transactions.
+ *
+ * @return
+ * TRUE if this connection supports transactions, FALSE otherwise.
+ */
+ public function supportsTransactions() {
+ return $this->transactionSupport;
+ }
+
+ /**
+ * Determines if this driver supports transactional DDL.
+ *
+ * DDL queries are those that change the schema, such as ALTER queries.
+ *
+ * @return
+ * TRUE if this connection supports transactions for DDL queries, FALSE
+ * otherwise.
+ */
+ public function supportsTransactionalDDL() {
+ return $this->transactionalDDLSupport;
+ }
+
+ /**
+ * Returns the name of the PDO driver for this connection.
+ */
+ abstract public function databaseType();
+
+
+ /**
+ * Gets any special processing requirements for the condition operator.
+ *
+ * Some condition types require special processing, such as IN, because
+ * the value data they pass in is not a simple value. This is a simple
+ * overridable lookup function. Database connections should define only
+ * those operators they wish to be handled differently than the default.
+ *
+ * @param $operator
+ * The condition operator, such as "IN", "BETWEEN", etc. Case-sensitive.
+ *
+ * @return
+ * The extra handling directives for the specified operator, or NULL.
+ *
+ * @see DatabaseCondition::compile()
+ */
+ abstract public function mapConditionOperator($operator);
+
+ /**
+ * Throws an exception to deny direct access to transaction commits.
+ *
+ * We do not want to allow users to commit transactions at any time, only
+ * by destroying the transaction object or allowing it to go out of scope.
+ * A direct commit bypasses all of the safety checks we've built on top of
+ * PDO's transaction routines.
+ *
+ * @throws DatabaseTransactionExplicitCommitNotAllowedException
+ *
+ * @see DatabaseTransaction
+ */
+ public function commit() {
+ throw new DatabaseTransactionExplicitCommitNotAllowedException();
+ }
+
+ /**
+ * Retrieves an unique id from a given sequence.
+ *
+ * Use this function if for some reason you can't use a serial field. For
+ * example, MySQL has no ways of reading of the current value of a sequence
+ * and PostgreSQL can not advance the sequence to be larger than a given
+ * value. Or sometimes you just need a unique integer.
+ *
+ * @param $existing_id
+ * After a database import, it might be that the sequences table is behind,
+ * so by passing in the maximum existing id, it can be assured that we
+ * never issue the same id.
+ *
+ * @return
+ * An integer number larger than any number returned by earlier calls and
+ * also larger than the $existing_id if one was passed in.
+ */
+ abstract public function nextId($existing_id = 0);
+}
+
+/**
+ * Primary front-controller for the database system.
+ *
+ * This class is uninstantiatable and un-extendable. It acts to encapsulate
+ * all control and shepherding of database connections into a single location
+ * without the use of globals.
+ */
+abstract class Database {
+
+ /**
+ * Flag to indicate a query call should simply return NULL.
+ *
+ * This is used for queries that have no reasonable return value anyway, such
+ * as INSERT statements to a table without a serial primary key.
+ */
+ const RETURN_NULL = 0;
+
+ /**
+ * Flag to indicate a query call should return the prepared statement.
+ */
+ const RETURN_STATEMENT = 1;
+
+ /**
+ * Flag to indicate a query call should return the number of affected rows.
+ */
+ const RETURN_AFFECTED = 2;
+
+ /**
+ * Flag to indicate a query call should return the "last insert id".
+ */
+ const RETURN_INSERT_ID = 3;
+
+ /**
+ * An nested array of all active connections. It is keyed by database name
+ * and target.
+ *
+ * @var array
+ */
+ static protected $connections = array();
+
+ /**
+ * A processed copy of the database connection information from settings.php.
+ *
+ * @var array
+ */
+ static protected $databaseInfo = NULL;
+
+ /**
+ * A list of key/target credentials to simply ignore.
+ *
+ * @var array
+ */
+ static protected $ignoreTargets = array();
+
+ /**
+ * The key of the currently active database connection.
+ *
+ * @var string
+ */
+ static protected $activeKey = 'default';
+
+ /**
+ * An array of active query log objects.
+ *
+ * Every connection has one and only one logger object for all targets and
+ * logging keys.
+ *
+ * array(
+ * '$db_key' => DatabaseLog object.
+ * );
+ *
+ * @var array
+ */
+ static protected $logs = array();
+
+ /**
+ * Starts logging a given logging key on the specified connection.
+ *
+ * @param $logging_key
+ * The logging key to log.
+ * @param $key
+ * The database connection key for which we want to log.
+ *
+ * @return DatabaseLog
+ * The query log object. Note that the log object does support richer
+ * methods than the few exposed through the Database class, so in some
+ * cases it may be desirable to access it directly.
+ *
+ * @see DatabaseLog
+ */
+ final public static function startLog($logging_key, $key = 'default') {
+ if (empty(self::$logs[$key])) {
+ self::$logs[$key] = new DatabaseLog($key);
+
+ // Every target already active for this connection key needs to have the
+ // logging object associated with it.
+ if (!empty(self::$connections[$key])) {
+ foreach (self::$connections[$key] as $connection) {
+ $connection->setLogger(self::$logs[$key]);
+ }
+ }
+ }
+
+ self::$logs[$key]->start($logging_key);
+ return self::$logs[$key];
+ }
+
+ /**
+ * Retrieves the queries logged on for given logging key.
+ *
+ * This method also ends logging for the specified key. To get the query log
+ * to date without ending the logger request the logging object by starting
+ * it again (which does nothing to an open log key) and call methods on it as
+ * desired.
+ *
+ * @param $logging_key
+ * The logging key to log.
+ * @param $key
+ * The database connection key for which we want to log.
+ *
+ * @return array
+ * The query log for the specified logging key and connection.
+ *
+ * @see DatabaseLog
+ */
+ final public static function getLog($logging_key, $key = 'default') {
+ if (empty(self::$logs[$key])) {
+ return NULL;
+ }
+ $queries = self::$logs[$key]->get($logging_key);
+ self::$logs[$key]->end($logging_key);
+ return $queries;
+ }
+
+ /**
+ * Gets the connection object for the specified database key and target.
+ *
+ * @param $target
+ * The database target name.
+ * @param $key
+ * The database connection key. Defaults to NULL which means the active key.
+ *
+ * @return DatabaseConnection
+ * The corresponding connection object.
+ */
+ final public static function getConnection($target = 'default', $key = NULL) {
+ if (!isset($key)) {
+ // By default, we want the active connection, set in setActiveConnection.
+ $key = self::$activeKey;
+ }
+ // If the requested target does not exist, or if it is ignored, we fall back
+ // to the default target. The target is typically either "default" or
+ // "slave", indicating to use a slave SQL server if one is available. If
+ // it's not available, then the default/master server is the correct server
+ // to use.
+ if (!empty(self::$ignoreTargets[$key][$target]) || !isset(self::$databaseInfo[$key][$target])) {
+ $target = 'default';
+ }
+
+ if (!isset(self::$connections[$key][$target])) {
+ // If necessary, a new connection is opened.
+ self::$connections[$key][$target] = self::openConnection($key, $target);
+ }
+ return self::$connections[$key][$target];
+ }
+
+ /**
+ * Determines if there is an active connection.
+ *
+ * Note that this method will return FALSE if no connection has been
+ * established yet, even if one could be.
+ *
+ * @return
+ * TRUE if there is at least one database connection established, FALSE
+ * otherwise.
+ */
+ final public static function isActiveConnection() {
+ return !empty(self::$activeKey) && !empty(self::$connections) && !empty(self::$connections[self::$activeKey]);
+ }
+
+ /**
+ * Sets the active connection to the specified key.
+ *
+ * @return
+ * The previous database connection key.
+ */
+ final public static function setActiveConnection($key = 'default') {
+ if (empty(self::$databaseInfo)) {
+ self::parseConnectionInfo();
+ }
+
+ if (!empty(self::$databaseInfo[$key])) {
+ $old_key = self::$activeKey;
+ self::$activeKey = $key;
+ return $old_key;
+ }
+ }
+
+ /**
+ * Process the configuration file for database information.
+ */
+ final public static function parseConnectionInfo() {
+ global $databases;
+
+ $database_info = is_array($databases) ? $databases : array();
+ foreach ($database_info as $index => $info) {
+ foreach ($database_info[$index] as $target => $value) {
+ // If there is no "driver" property, then we assume it's an array of
+ // possible connections for this target. Pick one at random. That allows
+ // us to have, for example, multiple slave servers.
+ if (empty($value['driver'])) {
+ $database_info[$index][$target] = $database_info[$index][$target][mt_rand(0, count($database_info[$index][$target]) - 1)];
+ }
+
+ // Parse the prefix information.
+ if (!isset($database_info[$index][$target]['prefix'])) {
+ // Default to an empty prefix.
+ $database_info[$index][$target]['prefix'] = array(
+ 'default' => '',
+ );
+ }
+ elseif (!is_array($database_info[$index][$target]['prefix'])) {
+ // Transform the flat form into an array form.
+ $database_info[$index][$target]['prefix'] = array(
+ 'default' => $database_info[$index][$target]['prefix'],
+ );
+ }
+ }
+ }
+
+ if (!is_array(self::$databaseInfo)) {
+ self::$databaseInfo = $database_info;
+ }
+
+ // Merge the new $database_info into the existing.
+ // array_merge_recursive() cannot be used, as it would make multiple
+ // database, user, and password keys in the same database array.
+ else {
+ foreach ($database_info as $database_key => $database_values) {
+ foreach ($database_values as $target => $target_values) {
+ self::$databaseInfo[$database_key][$target] = $target_values;
+ }
+ }
+ }
+ }
+
+ /**
+ * Adds database connection information for a given key/target.
+ *
+ * This method allows the addition of new connection credentials at runtime.
+ * Under normal circumstances the preferred way to specify database
+ * credentials is via settings.php. However, this method allows them to be
+ * added at arbitrary times, such as during unit tests, when connecting to
+ * admin-defined third party databases, etc.
+ *
+ * If the given key/target pair already exists, this method will be ignored.
+ *
+ * @param $key
+ * The database key.
+ * @param $target
+ * The database target name.
+ * @param $info
+ * The database connection information, as it would be defined in
+ * settings.php. Note that the structure of this array will depend on the
+ * database driver it is connecting to.
+ */
+ public static function addConnectionInfo($key, $target, $info) {
+ if (empty(self::$databaseInfo[$key][$target])) {
+ self::$databaseInfo[$key][$target] = $info;
+ }
+ }
+
+ /**
+ * Gets information on the specified database connection.
+ *
+ * @param $connection
+ * The connection key for which we want information.
+ */
+ final public static function getConnectionInfo($key = 'default') {
+ if (empty(self::$databaseInfo)) {
+ self::parseConnectionInfo();
+ }
+
+ if (!empty(self::$databaseInfo[$key])) {
+ return self::$databaseInfo[$key];
+ }
+ }
+
+ /**
+ * Rename a connection and its corresponding connection information.
+ *
+ * @param $old_key
+ * The old connection key.
+ * @param $new_key
+ * The new connection key.
+ * @return
+ * TRUE in case of success, FALSE otherwise.
+ */
+ final public static function renameConnection($old_key, $new_key) {
+ if (empty(self::$databaseInfo)) {
+ self::parseConnectionInfo();
+ }
+
+ if (!empty(self::$databaseInfo[$old_key]) && empty(self::$databaseInfo[$new_key])) {
+ // Migrate the database connection information.
+ self::$databaseInfo[$new_key] = self::$databaseInfo[$old_key];
+ unset(self::$databaseInfo[$old_key]);
+
+ // Migrate over the DatabaseConnection object if it exists.
+ if (isset(self::$connections[$old_key])) {
+ self::$connections[$new_key] = self::$connections[$old_key];
+ unset(self::$connections[$old_key]);
+ }
+
+ return TRUE;
+ }
+ else {
+ return FALSE;
+ }
+ }
+
+ /**
+ * Remove a connection and its corresponding connection information.
+ *
+ * @param $key
+ * The connection key.
+ * @return
+ * TRUE in case of success, FALSE otherwise.
+ */
+ final public static function removeConnection($key) {
+ if (isset(self::$databaseInfo[$key])) {
+ self::closeConnection(NULL, $key);
+ unset(self::$databaseInfo[$key]);
+ return TRUE;
+ }
+ else {
+ return FALSE;
+ }
+ }
+
+ /**
+ * Opens a connection to the server specified by the given key and target.
+ *
+ * @param $key
+ * The database connection key, as specified in settings.php. The default is
+ * "default".
+ * @param $target
+ * The database target to open.
+ *
+ * @throws DatabaseConnectionNotDefinedException
+ * @throws DatabaseDriverNotSpecifiedException
+ */
+ final protected static function openConnection($key, $target) {
+ if (empty(self::$databaseInfo)) {
+ self::parseConnectionInfo();
+ }
+
+ // If the requested database does not exist then it is an unrecoverable
+ // error.
+ if (!isset(self::$databaseInfo[$key])) {
+ throw new DatabaseConnectionNotDefinedException('The specified database connection is not defined: ' . $key);
+ }
+
+ if (!$driver = self::$databaseInfo[$key][$target]['driver']) {
+ throw new DatabaseDriverNotSpecifiedException('Driver not specified for this database connection: ' . $key);
+ }
+
+ // We cannot rely on the registry yet, because the registry requires an
+ // open database connection.
+ $driver_class = 'DatabaseConnection_' . $driver;
+ require_once DRUPAL_ROOT . '/includes/database/' . $driver . '/database.inc';
+ $new_connection = new $driver_class(self::$databaseInfo[$key][$target]);
+ $new_connection->setTarget($target);
+ $new_connection->setKey($key);
+
+ // If we have any active logging objects for this connection key, we need
+ // to associate them with the connection we just opened.
+ if (!empty(self::$logs[$key])) {
+ $new_connection->setLogger(self::$logs[$key]);
+ }
+
+ return $new_connection;
+ }
+
+ /**
+ * Closes a connection to the server specified by the given key and target.
+ *
+ * @param $target
+ * The database target name. Defaults to NULL meaning that all target
+ * connections will be closed.
+ * @param $key
+ * The database connection key. Defaults to NULL which means the active key.
+ */
+ public static function closeConnection($target = NULL, $key = NULL) {
+ // Gets the active connection by default.
+ if (!isset($key)) {
+ $key = self::$activeKey;
+ }
+ // To close a connection, it needs to be set to NULL and removed from the
+ // static variable. In all cases, closeConnection() might be called for a
+ // connection that was not opened yet, in which case the key is not defined
+ // yet and we just ensure that the connection key is undefined.
+ if (isset($target)) {
+ if (isset(self::$connections[$key][$target])) {
+ self::$connections[$key][$target]->destroy();
+ self::$connections[$key][$target] = NULL;
+ }
+ unset(self::$connections[$key][$target]);
+ }
+ else {
+ if (isset(self::$connections[$key])) {
+ foreach (self::$connections[$key] as $target => $connection) {
+ self::$connections[$key][$target]->destroy();
+ self::$connections[$key][$target] = NULL;
+ }
+ }
+ unset(self::$connections[$key]);
+ }
+ }
+
+ /**
+ * Instructs the system to temporarily ignore a given key/target.
+ *
+ * At times we need to temporarily disable slave queries. To do so, call this
+ * method with the database key and the target to disable. That database key
+ * will then always fall back to 'default' for that key, even if it's defined.
+ *
+ * @param $key
+ * The database connection key.
+ * @param $target
+ * The target of the specified key to ignore.
+ */
+ public static function ignoreTarget($key, $target) {
+ self::$ignoreTargets[$key][$target] = TRUE;
+ }
+
+ /**
+ * Load a file for the database that might hold a class.
+ *
+ * @param $driver
+ * The name of the driver.
+ * @param array $files
+ * The name of the files the driver specific class can be.
+ */
+ public static function loadDriverFile($driver, array $files = array()) {
+ static $base_path;
+
+ if (empty($base_path)) {
+ $base_path = dirname(realpath(__FILE__));
+ }
+
+ $driver_base_path = "$base_path/$driver";
+ foreach ($files as $file) {
+ // Load the base file first so that classes extending base classes will
+ // have the base class loaded.
+ foreach (array("$base_path/$file", "$driver_base_path/$file") as $filename) {
+ // The OS caches file_exists() and PHP caches require_once(), so
+ // we'll let both of those take care of performance here.
+ if (file_exists($filename)) {
+ require_once $filename;
+ }
+ }
+ }
+ }
+}
+
+/**
+ * Exception for when popTransaction() is called with no active transaction.
+ */
+class DatabaseTransactionNoActiveException extends Exception { }
+
+/**
+ * Exception thrown when a savepoint or transaction name occurs twice.
+ */
+class DatabaseTransactionNameNonUniqueException extends Exception { }
+
+/**
+ * Exception thrown when a commit() function fails.
+ */
+class DatabaseTransactionCommitFailedException extends Exception { }
+
+/**
+ * Exception to deny attempts to explicitly manage transactions.
+ *
+ * This exception will be thrown when the PDO connection commit() is called.
+ * Code should never call this method directly.
+ */
+class DatabaseTransactionExplicitCommitNotAllowedException extends Exception { }
+
+/**
+ * Exception thrown when a rollback() resulted in other active transactions being rolled-back.
+ */
+class DatabaseTransactionOutOfOrderException extends Exception { }
+
+/**
+ * Exception thrown for merge queries that do not make semantic sense.
+ *
+ * There are many ways that a merge query could be malformed. They should all
+ * throw this exception and set an appropriately descriptive message.
+ */
+class InvalidMergeQueryException extends Exception {}
+
+/**
+ * Exception thrown if an insert query specifies a field twice.
+ *
+ * It is not allowed to specify a field as default and insert field, this
+ * exception is thrown if that is the case.
+ */
+class FieldsOverlapException extends Exception {}
+
+/**
+ * Exception thrown if an insert query doesn't specify insert or default fields.
+ */
+class NoFieldsException extends Exception {}
+
+/**
+ * Exception thrown if an undefined database connection is requested.
+ */
+class DatabaseConnectionNotDefinedException extends Exception {}
+
+/**
+ * Exception thrown if no driver is specified for a database connection.
+ */
+class DatabaseDriverNotSpecifiedException extends Exception {}
+
+
+/**
+ * A wrapper class for creating and managing database transactions.
+ *
+ * Not all databases or database configurations support transactions. For
+ * example, MySQL MyISAM tables do not. It is also easy to begin a transaction
+ * and then forget to commit it, which can lead to connection errors when
+ * another transaction is started.
+ *
+ * This class acts as a wrapper for transactions. To begin a transaction,
+ * simply instantiate it. When the object goes out of scope and is destroyed
+ * it will automatically commit. It also will check to see if the specified
+ * connection supports transactions. If not, it will simply skip any transaction
+ * commands, allowing user-space code to proceed normally. The only difference
+ * is that rollbacks won't actually do anything.
+ *
+ * In the vast majority of cases, you should not instantiate this class
+ * directly. Instead, call ->startTransaction(), from the appropriate connection
+ * object.
+ */
+class DatabaseTransaction {
+
+ /**
+ * The connection object for this transaction.
+ *
+ * @var DatabaseConnection
+ */
+ protected $connection;
+
+ /**
+ * A boolean value to indicate whether this transaction has been rolled back.
+ *
+ * @var Boolean
+ */
+ protected $rolledBack = FALSE;
+
+ /**
+ * The name of the transaction.
+ *
+ * This is used to label the transaction savepoint. It will be overridden to
+ * 'drupal_transaction' if there is no transaction depth.
+ */
+ protected $name;
+
+ public function __construct(DatabaseConnection $connection, $name = NULL) {
+ $this->connection = $connection;
+ // If there is no transaction depth, then no transaction has started. Name
+ // the transaction 'drupal_transaction'.
+ if (!$depth = $connection->transactionDepth()) {
+ $this->name = 'drupal_transaction';
+ }
+ // Within transactions, savepoints are used. Each savepoint requires a
+ // name. So if no name is present we need to create one.
+ elseif (!$name) {
+ $this->name = 'savepoint_' . $depth;
+ }
+ else {
+ $this->name = $name;
+ }
+ $this->connection->pushTransaction($this->name);
+ }
+
+ public function __destruct() {
+ // If we rolled back then the transaction would have already been popped.
+ if (!$this->rolledBack) {
+ $this->connection->popTransaction($this->name);
+ }
+ }
+
+ /**
+ * Retrieves the name of the transaction or savepoint.
+ */
+ public function name() {
+ return $this->name;
+ }
+
+ /**
+ * Rolls back the current transaction.
+ *
+ * This is just a wrapper method to rollback whatever transaction stack we are
+ * currently in, which is managed by the connection object itself. Note that
+ * logging (preferable with watchdog_exception()) needs to happen after a
+ * transaction has been rolled back or the log messages will be rolled back
+ * too.
+ *
+ * @see DatabaseConnection::rollback()
+ * @see watchdog_exception()
+ */
+ public function rollback() {
+ $this->rolledBack = TRUE;
+ $this->connection->rollback($this->name);
+ }
+}
+
+/**
+ * Represents a prepared statement.
+ *
+ * Some methods in that class are purposefully commented out. Due to a change in
+ * how PHP defines PDOStatement, we can't define a signature for those methods
+ * that will work the same way between versions older than 5.2.6 and later
+ * versions. See http://bugs.php.net/bug.php?id=42452 for more details.
+ *
+ * Child implementations should either extend PDOStatement:
+ * @code
+ * class DatabaseStatement_oracle extends PDOStatement implements DatabaseStatementInterface {}
+ * @endcode
+ * or define their own class. If defining their own class, they will also have
+ * to implement either the Iterator or IteratorAggregate interface before
+ * DatabaseStatementInterface:
+ * @code
+ * class DatabaseStatement_oracle implements Iterator, DatabaseStatementInterface {}
+ * @endcode
+ */
+interface DatabaseStatementInterface extends Traversable {
+
+ /**
+ * Executes a prepared statement
+ *
+ * @param $args
+ * An array of values with as many elements as there are bound parameters in
+ * the SQL statement being executed.
+ * @param $options
+ * An array of options for this query.
+ *
+ * @return
+ * TRUE on success, or FALSE on failure.
+ */
+ public function execute($args = array(), $options = array());
+
+ /**
+ * Gets the query string of this statement.
+ *
+ * @return
+ * The query string, in its form with placeholders.
+ */
+ public function getQueryString();
+
+ /**
+ * Returns the number of rows affected by the last SQL statement.
+ *
+ * @return
+ * The number of rows affected by the last DELETE, INSERT, or UPDATE
+ * statement executed.
+ */
+ public function rowCount();
+
+ /**
+ * Sets the default fetch mode for this statement.
+ *
+ * See http://php.net/manual/pdo.constants.php for the definition of the
+ * constants used.
+ *
+ * @param $mode
+ * One of the PDO::FETCH_* constants.
+ * @param $a1
+ * An option depending of the fetch mode specified by $mode:
+ * - for PDO::FETCH_COLUMN, the index of the column to fetch
+ * - for PDO::FETCH_CLASS, the name of the class to create
+ * - for PDO::FETCH_INTO, the object to add the data to
+ * @param $a2
+ * If $mode is PDO::FETCH_CLASS, the optional arguments to pass to the
+ * constructor.
+ */
+ // public function setFetchMode($mode, $a1 = NULL, $a2 = array());
+
+ /**
+ * Fetches the next row from a result set.
+ *
+ * See http://php.net/manual/pdo.constants.php for the definition of the
+ * constants used.
+ *
+ * @param $mode
+ * One of the PDO::FETCH_* constants.
+ * Default to what was specified by setFetchMode().
+ * @param $cursor_orientation
+ * Not implemented in all database drivers, don't use.
+ * @param $cursor_offset
+ * Not implemented in all database drivers, don't use.
+ *
+ * @return
+ * A result, formatted according to $mode.
+ */
+ // public function fetch($mode = NULL, $cursor_orientation = NULL, $cursor_offset = NULL);
+
+ /**
+ * Returns a single field from the next record of a result set.
+ *
+ * @param $index
+ * The numeric index of the field to return. Defaults to the first field.
+ *
+ * @return
+ * A single field from the next record, or FALSE if there is no next record.
+ */
+ public function fetchField($index = 0);
+
+ /**
+ * Fetches the next row and returns it as an object.
+ *
+ * The object will be of the class specified by DatabaseStatementInterface::setFetchMode()
+ * or stdClass if not specified.
+ */
+ // public function fetchObject();
+
+ /**
+ * Fetches the next row and returns it as an associative array.
+ *
+ * This method corresponds to PDOStatement::fetchObject(), but for associative
+ * arrays. For some reason PDOStatement does not have a corresponding array
+ * helper method, so one is added.
+ *
+ * @return
+ * An associative array, or FALSE if there is no next row.
+ */
+ public function fetchAssoc();
+
+ /**
+ * Returns an array containing all of the result set rows.
+ *
+ * @param $mode
+ * One of the PDO::FETCH_* constants.
+ * @param $column_index
+ * If $mode is PDO::FETCH_COLUMN, the index of the column to fetch.
+ * @param $constructor_arguments
+ * If $mode is PDO::FETCH_CLASS, the arguments to pass to the constructor.
+ *
+ * @return
+ * An array of results.
+ */
+ // function fetchAll($mode = NULL, $column_index = NULL, array $constructor_arguments);
+
+ /**
+ * Returns an entire single column of a result set as an indexed array.
+ *
+ * Note that this method will run the result set to the end.
+ *
+ * @param $index
+ * The index of the column number to fetch.
+ *
+ * @return
+ * An indexed array, or an empty array if there is no result set.
+ */
+ public function fetchCol($index = 0);
+
+ /**
+ * Returns the entire result set as a single associative array.
+ *
+ * This method is only useful for two-column result sets. It will return an
+ * associative array where the key is one column from the result set and the
+ * value is another field. In most cases, the default of the first two columns
+ * is appropriate.
+ *
+ * Note that this method will run the result set to the end.
+ *
+ * @param $key_index
+ * The numeric index of the field to use as the array key.
+ * @param $value_index
+ * The numeric index of the field to use as the array value.
+ *
+ * @return
+ * An associative array, or an empty array if there is no result set.
+ */
+ public function fetchAllKeyed($key_index = 0, $value_index = 1);
+
+ /**
+ * Returns the result set as an associative array keyed by the given field.
+ *
+ * If the given key appears multiple times, later records will overwrite
+ * earlier ones.
+ *
+ * @param $key
+ * The name of the field on which to index the array.
+ * @param $fetch
+ * The fetchmode to use. If set to PDO::FETCH_ASSOC, PDO::FETCH_NUM, or
+ * PDO::FETCH_BOTH the returned value with be an array of arrays. For any
+ * other value it will be an array of objects. By default, the fetch mode
+ * set for the query will be used.
+ *
+ * @return
+ * An associative array, or an empty array if there is no result set.
+ */
+ public function fetchAllAssoc($key, $fetch = NULL);
+}
+
+/**
+ * Default implementation of DatabaseStatementInterface.
+ *
+ * PDO allows us to extend the PDOStatement class to provide additional
+ * functionality beyond that offered by default. We do need extra
+ * functionality. By default, this class is not driver-specific. If a given
+ * driver needs to set a custom statement class, it may do so in its
+ * constructor.
+ *
+ * @see http://us.php.net/pdostatement
+ */
+class DatabaseStatementBase extends PDOStatement implements DatabaseStatementInterface {
+
+ /**
+ * Reference to the database connection object for this statement.
+ *
+ * The name $dbh is inherited from PDOStatement.
+ *
+ * @var DatabaseConnection
+ */
+ public $dbh;
+
+ protected function __construct($dbh) {
+ $this->dbh = $dbh;
+ $this->setFetchMode(PDO::FETCH_OBJ);
+ }
+
+ public function execute($args = array(), $options = array()) {
+ if (isset($options['fetch'])) {
+ if (is_string($options['fetch'])) {
+ // Default to an object. Note: db fields will be added to the object
+ // before the constructor is run. If you need to assign fields after
+ // the constructor is run, see http://drupal.org/node/315092.
+ $this->setFetchMode(PDO::FETCH_CLASS, $options['fetch']);
+ }
+ else {
+ $this->setFetchMode($options['fetch']);
+ }
+ }
+
+ $logger = $this->dbh->getLogger();
+ if (!empty($logger)) {
+ $query_start = microtime(TRUE);
+ }
+
+ $return = parent::execute($args);
+
+ if (!empty($logger)) {
+ $query_end = microtime(TRUE);
+ $logger->log($this, $args, $query_end - $query_start);
+ }
+
+ return $return;
+ }
+
+ public function getQueryString() {
+ return $this->queryString;
+ }
+
+ public function fetchCol($index = 0) {
+ return $this->fetchAll(PDO::FETCH_COLUMN, $index);
+ }
+
+ public function fetchAllAssoc($key, $fetch = NULL) {
+ $return = array();
+ if (isset($fetch)) {
+ if (is_string($fetch)) {
+ $this->setFetchMode(PDO::FETCH_CLASS, $fetch);
+ }
+ else {
+ $this->setFetchMode($fetch);
+ }
+ }
+
+ foreach ($this as $record) {
+ $record_key = is_object($record) ? $record->$key : $record[$key];
+ $return[$record_key] = $record;
+ }
+
+ return $return;
+ }
+
+ public function fetchAllKeyed($key_index = 0, $value_index = 1) {
+ $return = array();
+ $this->setFetchMode(PDO::FETCH_NUM);
+ foreach ($this as $record) {
+ $return[$record[$key_index]] = $record[$value_index];
+ }
+ return $return;
+ }
+
+ public function fetchField($index = 0) {
+ // Call PDOStatement::fetchColumn to fetch the field.
+ return $this->fetchColumn($index);
+ }
+
+ public function fetchAssoc() {
+ // Call PDOStatement::fetch to fetch the row.
+ return $this->fetch(PDO::FETCH_ASSOC);
+ }
+}
+
+/**
+ * Empty implementation of a database statement.
+ *
+ * This class satisfies the requirements of being a database statement/result
+ * object, but does not actually contain data. It is useful when developers
+ * need to safely return an "empty" result set without connecting to an actual
+ * database. Calling code can then treat it the same as if it were an actual
+ * result set that happens to contain no records.
+ *
+ * @see SearchQuery
+ */
+class DatabaseStatementEmpty implements Iterator, DatabaseStatementInterface {
+
+ public function execute($args = array(), $options = array()) {
+ return FALSE;
+ }
+
+ public function getQueryString() {
+ return '';
+ }
+
+ public function rowCount() {
+ return 0;
+ }
+
+ public function setFetchMode($mode, $a1 = NULL, $a2 = array()) {
+ return;
+ }
+
+ public function fetch($mode = NULL, $cursor_orientation = NULL, $cursor_offset = NULL) {
+ return NULL;
+ }
+
+ public function fetchField($index = 0) {
+ return NULL;
+ }
+
+ public function fetchObject() {
+ return NULL;
+ }
+
+ public function fetchAssoc() {
+ return NULL;
+ }
+
+ function fetchAll($mode = NULL, $column_index = NULL, array $constructor_arguments = array()) {
+ return array();
+ }
+
+ public function fetchCol($index = 0) {
+ return array();
+ }
+
+ public function fetchAllKeyed($key_index = 0, $value_index = 1) {
+ return array();
+ }
+
+ public function fetchAllAssoc($key, $fetch = NULL) {
+ return array();
+ }
+
+ /* Implementations of Iterator. */
+
+ public function current() {
+ return NULL;
+ }
+
+ public function key() {
+ return NULL;
+ }
+
+ public function rewind() {
+ // Nothing to do: our DatabaseStatement can't be rewound.
+ }
+
+ public function next() {
+ // Do nothing, since this is an always-empty implementation.
+ }
+
+ public function valid() {
+ return FALSE;
+ }
+}
+
+/**
+ * The following utility functions are simply convenience wrappers.
+ *
+ * They should never, ever have any database-specific code in them.
+ */
+
+/**
+ * Executes an arbitrary query string against the active database.
+ *
+ * Use this function for SELECT queries if it is just a simple query string.
+ * If the caller or other modules need to change the query, use db_select()
+ * instead.
+ *
+ * Do not use this function for INSERT, UPDATE, or DELETE queries. Those should
+ * be handled via db_insert(), db_update() and db_delete() respectively.
+ *
+ * @param $query
+ * The prepared statement query to run. Although it will accept both named and
+ * unnamed placeholders, named placeholders are strongly preferred as they are
+ * more self-documenting.
+ * @param $args
+ * An array of values to substitute into the query. If the query uses named
+ * placeholders, this is an associative array in any order. If the query uses
+ * unnamed placeholders (?), this is an indexed array and the order must match
+ * the order of placeholders in the query string.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return DatabaseStatementInterface
+ * A prepared statement object, already executed.
+ *
+ * @see DatabaseConnection::defaultOptions()
+ */
+function db_query($query, array $args = array(), array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = 'default';
+ }
+
+ return Database::getConnection($options['target'])->query($query, $args, $options);
+}
+
+/**
+ * Executes a query against the active database, restricted to a range.
+ *
+ * @param $query
+ * The prepared statement query to run. Although it will accept both named and
+ * unnamed placeholders, named placeholders are strongly preferred as they are
+ * more self-documenting.
+ * @param $from
+ * The first record from the result set to return.
+ * @param $count
+ * The number of records to return from the result set.
+ * @param $args
+ * An array of values to substitute into the query. If the query uses named
+ * placeholders, this is an associative array in any order. If the query uses
+ * unnamed placeholders (?), this is an indexed array and the order must match
+ * the order of placeholders in the query string.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return DatabaseStatementInterface
+ * A prepared statement object, already executed.
+ *
+ * @see DatabaseConnection::defaultOptions()
+ */
+function db_query_range($query, $from, $count, array $args = array(), array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = 'default';
+ }
+
+ return Database::getConnection($options['target'])->queryRange($query, $from, $count, $args, $options);
+}
+
+/**
+ * Executes a query string and saves the result set to a temporary table.
+ *
+ * The execution of the query string happens against the active database.
+ *
+ * @param $query
+ * The prepared statement query to run. Although it will accept both named and
+ * unnamed placeholders, named placeholders are strongly preferred as they are
+ * more self-documenting.
+ * @param $args
+ * An array of values to substitute into the query. If the query uses named
+ * placeholders, this is an associative array in any order. If the query uses
+ * unnamed placeholders (?), this is an indexed array and the order must match
+ * the order of placeholders in the query string.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return
+ * The name of the temporary table.
+ *
+ * @see DatabaseConnection::defaultOptions()
+ */
+function db_query_temporary($query, array $args = array(), array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = 'default';
+ }
+
+ return Database::getConnection($options['target'])->queryTemporary($query, $args, $options);
+}
+
+/**
+ * Returns a new InsertQuery object for the active database.
+ *
+ * @param $table
+ * The table into which to insert.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return InsertQuery
+ * A new InsertQuery object for this connection.
+ */
+function db_insert($table, array $options = array()) {
+ if (empty($options['target']) || $options['target'] == 'slave') {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->insert($table, $options);
+}
+
+/**
+ * Returns a new MergeQuery object for the active database.
+ *
+ * @param $table
+ * The table into which to merge.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return MergeQuery
+ * A new MergeQuery object for this connection.
+ */
+function db_merge($table, array $options = array()) {
+ if (empty($options['target']) || $options['target'] == 'slave') {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->merge($table, $options);
+}
+
+/**
+ * Returns a new UpdateQuery object for the active database.
+ *
+ * @param $table
+ * The table to update.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return UpdateQuery
+ * A new UpdateQuery object for this connection.
+ */
+function db_update($table, array $options = array()) {
+ if (empty($options['target']) || $options['target'] == 'slave') {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->update($table, $options);
+}
+
+/**
+ * Returns a new DeleteQuery object for the active database.
+ *
+ * @param $table
+ * The table from which to delete.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return DeleteQuery
+ * A new DeleteQuery object for this connection.
+ */
+function db_delete($table, array $options = array()) {
+ if (empty($options['target']) || $options['target'] == 'slave') {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->delete($table, $options);
+}
+
+/**
+ * Returns a new TruncateQuery object for the active database.
+ *
+ * @param $table
+ * The table from which to delete.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return TruncateQuery
+ * A new TruncateQuery object for this connection.
+ */
+function db_truncate($table, array $options = array()) {
+ if (empty($options['target']) || $options['target'] == 'slave') {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->truncate($table, $options);
+}
+
+/**
+ * Returns a new SelectQuery object for the active database.
+ *
+ * @param $table
+ * The base table for this query. May be a string or another SelectQuery
+ * object. If a query object is passed, it will be used as a subselect.
+ * @param $alias
+ * The alias for the base table of this query.
+ * @param $options
+ * An array of options to control how the query operates.
+ *
+ * @return SelectQuery
+ * A new SelectQuery object for this connection.
+ */
+function db_select($table, $alias = NULL, array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->select($table, $alias, $options);
+}
+
+/**
+ * Returns a new transaction object for the active database.
+ *
+ * @param string $name
+ * Optional name of the transaction.
+ * @param array $options
+ * An array of options to control how the transaction operates:
+ * - target: The database target name.
+ *
+ * @return DatabaseTransaction
+ * A new DatabaseTransaction object for this connection.
+ */
+function db_transaction($name = NULL, array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = 'default';
+ }
+ return Database::getConnection($options['target'])->startTransaction($name);
+}
+
+/**
+ * Sets a new active database.
+ *
+ * @param $key
+ * The key in the $databases array to set as the default database.
+ *
+ * @return
+ * The key of the formerly active database.
+ */
+function db_set_active($key = 'default') {
+ return Database::setActiveConnection($key);
+}
+
+/**
+ * Restricts a dynamic table name to safe characters.
+ *
+ * Only keeps alphanumeric and underscores.
+ *
+ * @param $table
+ * The table name to escape.
+ *
+ * @return
+ * The escaped table name as a string.
+ */
+function db_escape_table($table) {
+ return Database::getConnection()->escapeTable($table);
+}
+
+/**
+ * Restricts a dynamic column or constraint name to safe characters.
+ *
+ * Only keeps alphanumeric and underscores.
+ *
+ * @param $field
+ * The field name to escape.
+ *
+ * @return
+ * The escaped field name as a string.
+ */
+function db_escape_field($field) {
+ return Database::getConnection()->escapeField($field);
+}
+
+/**
+ * Escapes characters that work as wildcard characters in a LIKE pattern.
+ *
+ * The wildcard characters "%" and "_" as well as backslash are prefixed with
+ * a backslash. Use this to do a search for a verbatim string without any
+ * wildcard behavior.
+ *
+ * For example, the following does a case-insensitive query for all rows whose
+ * name starts with $prefix:
+ * @code
+ * $result = db_query(
+ * 'SELECT * FROM person WHERE name LIKE :pattern',
+ * array(':pattern' => db_like($prefix) . '%')
+ * );
+ * @endcode
+ *
+ * Backslash is defined as escape character for LIKE patterns in
+ * DatabaseCondition::mapConditionOperator().
+ *
+ * @param $string
+ * The string to escape.
+ *
+ * @return
+ * The escaped string.
+ */
+function db_like($string) {
+ return Database::getConnection()->escapeLike($string);
+}
+
+/**
+ * Retrieves the name of the currently active database driver.
+ *
+ * @return
+ * The name of the currently active database driver.
+ */
+function db_driver() {
+ return Database::getConnection()->driver();
+}
+
+/**
+ * Closes the active database connection.
+ *
+ * @param $options
+ * An array of options to control which connection is closed. Only the target
+ * key has any meaning in this case.
+ */
+function db_close(array $options = array()) {
+ if (empty($options['target'])) {
+ $options['target'] = NULL;
+ }
+ Database::closeConnection($options['target']);
+}
+
+/**
+ * Retrieves a unique id.
+ *
+ * Use this function if for some reason you can't use a serial field. Using a
+ * serial field is preferred, and InsertQuery::execute() returns the value of
+ * the last ID inserted.
+ *
+ * @param $existing_id
+ * After a database import, it might be that the sequences table is behind, so
+ * by passing in a minimum ID, it can be assured that we never issue the same
+ * ID.
+ *
+ * @return
+ * An integer number larger than any number returned before for this sequence.
+ */
+function db_next_id($existing_id = 0) {
+ return Database::getConnection()->nextId($existing_id);
+}
+
+/**
+ * Returns a new DatabaseCondition, set to "OR" all conditions together.
+ *
+ * @return DatabaseCondition
+ */
+function db_or() {
+ return new DatabaseCondition('OR');
+}
+
+/**
+ * Returns a new DatabaseCondition, set to "AND" all conditions together.
+ *
+ * @return DatabaseCondition
+ */
+function db_and() {
+ return new DatabaseCondition('AND');
+}
+
+/**
+ * Returns a new DatabaseCondition, set to "XOR" all conditions together.
+ *
+ * @return DatabaseCondition
+ */
+function db_xor() {
+ return new DatabaseCondition('XOR');
+}
+
+/**
+ * Returns a new DatabaseCondition, set to the specified conjunction.
+ *
+ * Internal API function call. The db_and(), db_or(), and db_xor()
+ * functions are preferred.
+ *
+ * @param $conjunction
+ * The conjunction to use for query conditions (AND, OR or XOR).
+ * @return DatabaseCondition
+ */
+function db_condition($conjunction) {
+ return new DatabaseCondition($conjunction);
+}
+
+/**
+ * @} End of "defgroup database".
+ */
+
+
+/**
+ * @addtogroup schemaapi
+ * @{
+ */
+
+/**
+ * Creates a new table from a Drupal table definition.
+ *
+ * @param $name
+ * The name of the table to create.
+ * @param $table
+ * A Schema API table definition array.
+ */
+function db_create_table($name, $table) {
+ return Database::getConnection()->schema()->createTable($name, $table);
+}
+
+/**
+ * Returns an array of field names from an array of key/index column specifiers.
+ *
+ * This is usually an identity function but if a key/index uses a column prefix
+ * specification, this function extracts just the name.
+ *
+ * @param $fields
+ * An array of key/index column specifiers.
+ *
+ * @return
+ * An array of field names.
+ */
+function db_field_names($fields) {
+ return Database::getConnection()->schema()->fieldNames($fields);
+}
+
+/**
+ * Checks if an index exists in the given table.
+ *
+ * @param $table
+ * The name of the table in drupal (no prefixing).
+ * @param $name
+ * The name of the index in drupal (no prefixing).
+ *
+ * @return
+ * TRUE if the given index exists, otherwise FALSE.
+ */
+function db_index_exists($table, $name) {
+ return Database::getConnection()->schema()->indexExists($table, $name);
+}
+
+/**
+ * Checks if a table exists.
+ *
+ * @param $table
+ * The name of the table in drupal (no prefixing).
+ *
+ * @return
+ * TRUE if the given table exists, otherwise FALSE.
+ */
+function db_table_exists($table) {
+ return Database::getConnection()->schema()->tableExists($table);
+}
+
+/**
+ * Checks if a column exists in the given table.
+ *
+ * @param $table
+ * The name of the table in drupal (no prefixing).
+ * @param $field
+ * The name of the field.
+ *
+ * @return
+ * TRUE if the given column exists, otherwise FALSE.
+ */
+function db_field_exists($table, $field) {
+ return Database::getConnection()->schema()->fieldExists($table, $field);
+}
+
+/**
+ * Finds all tables that are like the specified base table name.
+ *
+ * @param $table_expression
+ * An SQL expression, for example "simpletest%" (without the quotes).
+ * BEWARE: this is not prefixed, the caller should take care of that.
+ *
+ * @return
+ * Array, both the keys and the values are the matching tables.
+ */
+function db_find_tables($table_expression) {
+ return Database::getConnection()->schema()->findTables($table_expression);
+}
+
+function _db_create_keys_sql($spec) {
+ return Database::getConnection()->schema()->createKeysSql($spec);
+}
+
+/**
+ * Renames a table.
+ *
+ * @param $table
+ * The current name of the table to be renamed.
+ * @param $new_name
+ * The new name for the table.
+ */
+function db_rename_table($table, $new_name) {
+ return Database::getConnection()->schema()->renameTable($table, $new_name);
+}
+
+/**
+ * Drops a table.
+ *
+ * @param $table
+ * The table to be dropped.
+ */
+function db_drop_table($table) {
+ return Database::getConnection()->schema()->dropTable($table);
+}
+
+/**
+ * Adds a new field to a table.
+ *
+ * @param $table
+ * Name of the table to be altered.
+ * @param $field
+ * Name of the field to be added.
+ * @param $spec
+ * The field specification array, as taken from a schema definition. The
+ * specification may also contain the key 'initial'; the newly-created field
+ * will be set to the value of the key in all rows. This is most useful for
+ * creating NOT NULL columns with no default value in existing tables.
+ * @param $keys_new
+ * Optional keys and indexes specification to be created on the table along
+ * with adding the field. The format is the same as a table specification, but
+ * without the 'fields' element. If you are adding a type 'serial' field, you
+ * MUST specify at least one key or index including it in this array. See
+ * db_change_field() for more explanation why.
+ *
+ * @see db_change_field()
+ */
+function db_add_field($table, $field, $spec, $keys_new = array()) {
+ return Database::getConnection()->schema()->addField($table, $field, $spec, $keys_new);
+}
+
+/**
+ * Drops a field.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $field
+ * The field to be dropped.
+ */
+function db_drop_field($table, $field) {
+ return Database::getConnection()->schema()->dropField($table, $field);
+}
+
+/**
+ * Sets the default value for a field.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $field
+ * The field to be altered.
+ * @param $default
+ * Default value to be set. NULL for 'default NULL'.
+ */
+function db_field_set_default($table, $field, $default) {
+ return Database::getConnection()->schema()->fieldSetDefault($table, $field, $default);
+}
+
+/**
+ * Sets a field to have no default value.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $field
+ * The field to be altered.
+ */
+function db_field_set_no_default($table, $field) {
+ return Database::getConnection()->schema()->fieldSetNoDefault($table, $field);
+}
+
+/**
+ * Adds a primary key to a database table.
+ *
+ * @param $table
+ * Name of the table to be altered.
+ * @param $fields
+ * Array of fields for the primary key.
+ */
+function db_add_primary_key($table, $fields) {
+ return Database::getConnection()->schema()->addPrimaryKey($table, $fields);
+}
+
+/**
+ * Drops the primary key of a database table.
+ *
+ * @param $table
+ * Name of the table to be altered.
+ */
+function db_drop_primary_key($table) {
+ return Database::getConnection()->schema()->dropPrimaryKey($table);
+}
+
+/**
+ * Adds a unique key.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $name
+ * The name of the key.
+ * @param $fields
+ * An array of field names.
+ */
+function db_add_unique_key($table, $name, $fields) {
+ return Database::getConnection()->schema()->addUniqueKey($table, $name, $fields);
+}
+
+/**
+ * Drops a unique key.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $name
+ * The name of the key.
+ */
+function db_drop_unique_key($table, $name) {
+ return Database::getConnection()->schema()->dropUniqueKey($table, $name);
+}
+
+/**
+ * Adds an index.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $name
+ * The name of the index.
+ * @param $fields
+ * An array of field names.
+ */
+function db_add_index($table, $name, $fields) {
+ return Database::getConnection()->schema()->addIndex($table, $name, $fields);
+}
+
+/**
+ * Drops an index.
+ *
+ * @param $table
+ * The table to be altered.
+ * @param $name
+ * The name of the index.
+ */
+function db_drop_index($table, $name) {
+ return Database::getConnection()->schema()->dropIndex($table, $name);
+}
+
+/**
+ * Changes a field definition.
+ *
+ * IMPORTANT NOTE: To maintain database portability, you have to explicitly
+ * recreate all indices and primary keys that are using the changed field.
+ *
+ * That means that you have to drop all affected keys and indexes with
+ * db_drop_{primary_key,unique_key,index}() before calling db_change_field().
+ * To recreate the keys and indices, pass the key definitions as the optional
+ * $keys_new argument directly to db_change_field().
+ *
+ * For example, suppose you have:
+ * @code
+ * $schema['foo'] = array(
+ * 'fields' => array(
+ * 'bar' => array('type' => 'int', 'not null' => TRUE)
+ * ),
+ * 'primary key' => array('bar')
+ * );
+ * @endcode
+ * and you want to change foo.bar to be type serial, leaving it as the primary
+ * key. The correct sequence is:
+ * @code
+ * db_drop_primary_key('foo');
+ * db_change_field('foo', 'bar', 'bar',
+ * array('type' => 'serial', 'not null' => TRUE),
+ * array('primary key' => array('bar')));
+ * @endcode
+ *
+ * The reasons for this are due to the different database engines:
+ *
+ * On PostgreSQL, changing a field definition involves adding a new field and
+ * dropping an old one which causes any indices, primary keys and sequences
+ * (from serial-type fields) that use the changed field to be dropped.
+ *
+ * On MySQL, all type 'serial' fields must be part of at least one key or index
+ * as soon as they are created. You cannot use
+ * db_add_{primary_key,unique_key,index}() for this purpose because the ALTER
+ * TABLE command will fail to add the column without a key or index
+ * specification. The solution is to use the optional $keys_new argument to
+ * create the key or index at the same time as field.
+ *
+ * You could use db_add_{primary_key,unique_key,index}() in all cases unless you
+ * are converting a field to be type serial. You can use the $keys_new argument
+ * in all cases.
+ *
+ * @param $table
+ * Name of the table.
+ * @param $field
+ * Name of the field to change.
+ * @param $field_new
+ * New name for the field (set to the same as $field if you don't want to
+ * change the name).
+ * @param $spec
+ * The field specification for the new field.
+ * @param $keys_new
+ * Optional keys and indexes specification to be created on the table along
+ * with changing the field. The format is the same as a table specification
+ * but without the 'fields' element.
+ */
+function db_change_field($table, $field, $field_new, $spec, $keys_new = array()) {
+ return Database::getConnection()->schema()->changeField($table, $field, $field_new, $spec, $keys_new);
+}
+
+/**
+ * @} End of "addtogroup schemaapi".
+ */
+
+/**
+ * Sets a session variable specifying the lag time for ignoring a slave server.
+ */
+function db_ignore_slave() {
+ $connection_info = Database::getConnectionInfo();
+ // Only set ignore_slave_server if there are slave servers being used, which
+ // is assumed if there are more than one.
+ if (count($connection_info) > 1) {
+ // Five minutes is long enough to allow the slave to break and resume
+ // interrupted replication without causing problems on the Drupal site from
+ // the old data.
+ $duration = variable_get('maximum_replication_lag', 300);
+ // Set session variable with amount of time to delay before using slave.
+ $_SESSION['ignore_slave_server'] = REQUEST_TIME + $duration;
+ }
+}