class InsertQuery_pgsql

class InsertQuery_pgsql extends InsertQuery {
    public function execute() {
        if (!$this->preExecute()) {
            return NULL;
        }
        $stmt = $this->connection
            ->prepareQuery((string) $this);
        // Fetch the list of blobs and sequences used on that table.
        $table_information = $this->connection
            ->schema()
            ->queryTableInformation($this->table);
        $max_placeholder = 0;
        $blobs = array();
        $blob_count = 0;
        foreach ($this->insertValues as $insert_values) {
            foreach ($this->insertFields as $idx => $field) {
                if (isset($table_information->blob_fields[$field])) {
                    $blobs[$blob_count] = fopen('php://memory', 'a');
                    fwrite($blobs[$blob_count], (string) $insert_values[$idx]);
                    rewind($blobs[$blob_count]);
                    $stmt->bindParam(':db_insert_placeholder_' . $max_placeholder++, $blobs[$blob_count], PDO::PARAM_LOB);
                    // Pre-increment is faster in PHP than increment.
                    ++$blob_count;
                }
                else {
                    $stmt->bindParam(':db_insert_placeholder_' . $max_placeholder++, $insert_values[$idx]);
                }
            }
            // Check if values for a serial field has been passed.
            if (!empty($table_information->serial_fields)) {
                foreach ($table_information->serial_fields as $index => $serial_field) {
                    $serial_key = array_search($serial_field, $this->insertFields);
                    if ($serial_key !== FALSE) {
                        $serial_value = $insert_values[$serial_key];
                        // Force $last_insert_id to the specified value. This is only done
                        // if $index is 0.
                        if ($index == 0) {
                            $last_insert_id = $serial_value;
                        }
                        // Set the sequence to the bigger value of either the passed
                        // value or the max value of the column. It can happen that another
                        // thread calls nextval() which could lead to a serial number being
                        // used twice. However, trying to insert a value into a serial
                        // column should only be done in very rare cases and is not thread
                        // safe by definition.
                        $this->connection
                            ->query("SELECT setval('" . $table_information->sequences[$index] . "', GREATEST(MAX(" . $serial_field . "), :serial_value)) FROM {" . $this->table . "}", array(
                            ':serial_value' => (int) $serial_value,
                        ));
                    }
                }
            }
        }
        if (!empty($this->fromQuery)) {
            // bindParam stores only a reference to the variable that is followed when
            // the statement is executed. We pass $arguments[$key] instead of $value
            // because the second argument to bindParam is passed by reference and
            // the foreach statement assigns the element to the existing reference.
            $arguments = $this->fromQuery
                ->getArguments();
            foreach ($arguments as $key => $value) {
                $stmt->bindParam($key, $arguments[$key]);
            }
        }
        // PostgreSQL requires the table name to be specified explicitly
        // when requesting the last insert ID, so we pass that in via
        // the options array.
        $options = $this->queryOptions;
        if (!empty($table_information->sequences)) {
            $options['sequence_name'] = $table_information->sequences[0];
        }
        elseif ($options['return'] == Database::RETURN_INSERT_ID) {
            $options['return'] = Database::RETURN_NULL;
        }
        // Only use the returned last_insert_id if it is not already set.
        if (!empty($last_insert_id)) {
            $this->connection
                ->query($stmt, array(), $options);
        }
        else {
            $last_insert_id = $this->connection
                ->query($stmt, array(), $options);
        }
        // Re-initialize the values array so that we can re-use this query.
        $this->insertValues = array();
        return $last_insert_id;
    }
    public function __toString() {
        // Create a sanitized comment string to prepend to the query.
        $comments = $this->connection
            ->makeComment($this->comments);
        // Default fields are always placed first for consistency.
        $insert_fields = array_merge($this->defaultFields, $this->insertFields);
        // If we're selecting from a SelectQuery, finish building the query and
        // pass it back, as any remaining options are irrelevant.
        if (!empty($this->fromQuery)) {
            $insert_fields_string = $insert_fields ? ' (' . implode(', ', $insert_fields) . ') ' : ' ';
            return $comments . 'INSERT INTO {' . $this->table . '}' . $insert_fields_string . $this->fromQuery;
        }
        $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
        $max_placeholder = 0;
        $values = array();
        if (count($this->insertValues)) {
            foreach ($this->insertValues as $insert_values) {
                $placeholders = array();
                // Default fields aren't really placeholders, but this is the most convenient
                // way to handle them.
                $placeholders = array_pad($placeholders, count($this->defaultFields), 'default');
                $new_placeholder = $max_placeholder + count($insert_values);
                for ($i = $max_placeholder; $i < $new_placeholder; ++$i) {
                    $placeholders[] = ':db_insert_placeholder_' . $i;
                }
                $max_placeholder = $new_placeholder;
                $values[] = '(' . implode(', ', $placeholders) . ')';
            }
        }
        else {
            // If there are no values, then this is a default-only query. We still need to handle that.
            $placeholders = array_fill(0, count($this->defaultFields), 'default');
            $values[] = '(' . implode(', ', $placeholders) . ')';
        }
        $query .= implode(', ', $values);
        return $query;
    }

}