Postgres::getRowIdentifier PHP Method

    function getRowIdentifier($table)
    {
        $oldtable = $table;
        $c_schema = $this->_schema;
        $this->clean($c_schema);
        $this->clean($table);
        $status = $this->beginTransaction();
        if ($status != 0) {
            return -1;
        }
        // Get the first primary or unique index (sorting primary keys first) that
        // is NOT a partial index.
        $sql = "\n\t\t\tSELECT indrelid, indkey\n\t\t\tFROM pg_catalog.pg_index\n\t\t\tWHERE indisunique AND indrelid=(\n\t\t\t\tSELECT oid FROM pg_catalog.pg_class\n\t\t\t\tWHERE relname='{$table}' AND relnamespace=(\n\t\t\t\t\tSELECT oid FROM pg_catalog.pg_namespace\n\t\t\t\t\tWHERE nspname='{$c_schema}'\n\t\t\t\t)\n\t\t\t) AND indpred IS NULL AND indexprs IS NULL\n\t\t\tORDER BY indisprimary DESC LIMIT 1";
        $rs = $this->selectSet($sql);
        // If none, check for an OID column.  Even though OIDs can be duplicated, the edit and delete row
        // functions check that they're only modiying a single row.  Otherwise, return empty array.
        if ($rs->recordCount() == 0) {
            // Check for OID column
            $temp = array();
            if ($this->hasObjectID($table)) {
                $temp = array('oid');
            }
            $this->endTransaction();
            return $temp;
        } else {
            $attnames = $this->getAttributeNames($oldtable, explode(' ', $rs->fields['indkey']));
            if (!is_array($attnames)) {
                $this->rollbackTransaction();
                return -1;
            } else {
                $this->endTransaction();
                return $attnames;
            }
        }
    }