class DatabaseConnection_pgsql

class DatabaseConnection_pgsql  extends DatabaseConnection {
 public function __construct(array $connection_options = array()) {
 // This driver defaults to transaction support, except if explicitly passed FALSE.
 $this->transactionSupport  = !isset($connection_options['transactions']) || $connection_options['transactions'] !== FALSE;
 // Transactional DDL is always available in PostgreSQL,
 // but we'll only enable it if standard transactions are.
 $this->transactionalDDLSupport  = $this->transactionSupport ;
 // Default to TCP connection on port 5432.
 if (empty($connection_options['port'])) {
 $connection_options['port'] = 5432;
 }
 // PostgreSQL in trust mode doesn't require a password to be supplied.
 if (empty($connection_options['password'])) {
 $connection_options['password'] = NULL;
 }
 else {
 $connection_options['password'] = str_replace ('\\', '\\\\', $connection_options['password']);
 }
 $this->connectionOptions  = $connection_options;
 $dsn = 'pgsql:host=' . $connection_options['host'] . ' dbname=' . $connection_options['database'] . ' port=' . $connection_options['port'];
 // Allow PDO options to be overridden.
 $connection_options += array(
 'pdo' => array(),
 );
 $connection_options['pdo'] += array(
 // Prepared statements are most effective for performance when queries
 // are recycled (used several times). However, if they are not re-used,
 // prepared statements become inefficient. Since most of Drupal's
 // prepared queries are not re-used, it should be faster to emulate
 // the preparation than to actually ready statements for re-use. If in
 // doubt, reset to FALSE and measure performance.
PDO::ATTR_EMULATE_PREPARES => TRUE,
 // Convert numeric values to strings when fetching.
PDO::ATTR_STRINGIFY_FETCHES => TRUE,
 );
 parent ::__construct ($dsn, $connection_options['username'], $connection_options['password'], $connection_options['pdo']);
 // Force PostgreSQL to use the UTF-8 character set by default.
 $this->connection 
 ->exec("SET NAMES 'UTF8'");
 // Execute PostgreSQL init_commands.
 if (isset($connection_options['init_commands'])) {
 $this->connection 
 ->exec(implode ('; ', $connection_options['init_commands']));
 }
 }
 public function prepareQuery($query) {
 // mapConditionOperator converts LIKE operations to ILIKE for consistency
 // with MySQL. However, Postgres does not support ILIKE on bytea (blobs)
 // fields.
 // To make the ILIKE operator work, we type-cast bytea fields into text.
 // @todo This workaround only affects bytea fields, but the involved field
 // types involved in the query are unknown, so there is no way to
 // conditionally execute this for affected queries only.
 return parent ::prepareQuery (preg_replace ('/ ([^ ]+) +(I*LIKE|NOT +I*LIKE) /i', ' ${1}::text ${2} ', $query));
 }
 public function query($query, array $args = array(), $options = array()) {
 $options += $this->defaultOptions ();
 // The PDO PostgreSQL driver has a bug which
 // doesn't type cast booleans correctly when
 // parameters are bound using associative
 // arrays.
 // See http://bugs.php.net/bug.php?id=48383
 foreach ($args as &$value) {
 if (is_bool ($value)) {
 $value = (int) $value;
 }
 }
 try {
 if ($query instanceof DatabaseStatementInterface) {
 $stmt = $query;
 $stmt->execute (NULL, $options);
 }
 else {
 $this->expandArguments ($query, $args);
 $stmt = $this->prepareQuery ($query);
 $stmt->execute ($args, $options);
 }
 switch ($options['return']) {
 case Database::RETURN_STATEMENT:
 return $stmt;
 case Database::RETURN_AFFECTED:
 return $stmt->rowCount ();
 case Database::RETURN_INSERT_ID:
 $sequence_name = isset($options['sequence_name']) ? $options['sequence_name'] : NULL;
 return $this->connection 
 ->lastInsertId($sequence_name);
 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->errorInfo['query_string'] = $stmt->getQueryString ();
 }
 else {
 $e->errorInfo['query_string'] = $query;
 }
 $e->errorInfo['args'] = $args;
 throw $e;
 }
 return NULL;
 }
 }
 public function queryRange($query, $from, $count, array $args = array(), array $options = array()) {
 return $this->query ($query . ' LIMIT ' . (int) $count . ' OFFSET ' . (int) $from, $args, $options);
 }
 public function queryTemporary($query, array $args = array(), array $options = array()) {
 $tablename = $this->generateTemporaryTableName ();
 $this->query ('CREATE TEMPORARY TABLE {' . $tablename . '} AS ' . $query, $args, $options);
 return $tablename;
 }
 public function driver() {
 return 'pgsql';
 }
 public function databaseType() {
 return 'pgsql';
 }
 public function mapConditionOperator($operator) {
 static $specials;
 // Function calls not allowed in static declarations, thus this method.
 if (!isset($specials)) {
 $specials = array(
 // In PostgreSQL, 'LIKE' is case-sensitive. For case-insensitive LIKE
 // statements, we need to use ILIKE instead.
'LIKE' => array(
 'operator' => 'ILIKE',
 ),
 'NOT LIKE' => array(
 'operator' => 'NOT ILIKE',
 ),
 );
 }
 return isset($specials[$operator]) ? $specials[$operator] : NULL;
 }
 
 /**
 * Retrieve the next id in a sequence.
 *
 * PostgreSQL has built in sequences. We'll use these instead of inserting
 * and updating a sequences table.
 */
 public function nextId($existing = 0) {
 // Retrieve the name of the sequence. This information cannot be cached
 // because the prefix may change, for example, like it does in simpletests.
 $sequence_name = $this->makeSequenceName ('sequences', 'value');
 // When PostgreSQL gets a value too small then it will lock the table,
 // retry the INSERT and if it's still too small then alter the sequence.
 $id = $this->query ("SELECT nextval('" . $sequence_name . "')")
 ->fetchField ();
 if ($id > $existing) {
 return $id;
 }
 // PostgreSQL advisory locks are simply locks to be used by an
 // application such as Drupal. This will prevent other Drupal processes
 // from altering the sequence while we are.
 $this->query ("SELECT pg_advisory_lock(" . POSTGRESQL_NEXTID_LOCK  . ")");
 // While waiting to obtain the lock, the sequence may have been altered
 // so lets try again to obtain an adequate value.
 $id = $this->query ("SELECT nextval('" . $sequence_name . "')")
 ->fetchField ();
 if ($id > $existing) {
 $this->query ("SELECT pg_advisory_unlock(" . POSTGRESQL_NEXTID_LOCK  . ")");
 return $id;
 }
 // Reset the sequence to a higher value than the existing id.
 $this->query ("ALTER SEQUENCE " . $sequence_name . " RESTART WITH " . ($existing + 1));
 // Retrieve the next id. We know this will be as high as we want it.
 $id = $this->query ("SELECT nextval('" . $sequence_name . "')")
 ->fetchField ();
 $this->query ("SELECT pg_advisory_unlock(" . POSTGRESQL_NEXTID_LOCK  . ")");
 return $id;
 }
 public function utf8mb4IsActive() {
 return TRUE;
 }
 public function utf8mb4IsSupported() {
 return TRUE;
 }
}