private static function _sequenceExists()
    {
        if (Driver::$primary_key_behaviour != Driver::PRIMARY_KEY_SEQUENCE) {
            return null;
        }

        // caching if the sequence exists
        $cls  = get_called_class();
        $name = self::resolveSequenceName();

        if (array_key_exists($cls, self::$_sequence_exists)
            && array_key_exists($name, self::$_sequence_exists[$cls])
        ) {
            return true;
        }

        $rtn = false;

        switch (Driver::$name) {
        case "oracle":
            $rtn = self::_oracleSequenceExists($name);
            break;
        case "postgresql":
            $rtn = self::_postgresqlSequenceExists($name);
            break;
        }

        // if exists, cache result
        if ($rtn) {
            if (!array_key_exists($cls, self::$_sequence_exists)) {
                self::$_sequence_exists[$cls] = array();
            }
            self::$_sequence_exists[$cls][$name] = true;
        }
        return $rtn;
    }
private static function _sequenceExists()
    {
        if (Driver::$primary_key_behaviour != Driver::PRIMARY_KEY_SEQUENCE) {
            return null;
        }

        // caching if the sequence exists
        $cls  = get_called_class();
        $name = self::resolveSequenceName();

        if (array_key_exists($cls, self::$_sequence_exists)
            && array_key_exists($name, self::$_sequence_exists[$cls])
        ) {
            return true;
        }

        $rtn = false;

        switch (Driver::$name) {
        case "oracle":
            $rtn = self::_oracleSequenceExists($name);
            break;
        case "postgresql":
            $rtn = self::_postgresqlSequenceExists($name);
            break;
        }

        // if exists, cache result
        if ($rtn) {
            if (!array_key_exists($cls, self::$_sequence_exists)) {
                self::$_sequence_exists[$cls] = array();
            }
            self::$_sequence_exists[$cls][$name] = true;
        }
        return $rtn;
    }
private static function _sequenceExists ( ) { if ( Driver :: $ primary_key_behaviour != Driver :: PRIMARY_KEY_SEQUENCE ) { return null ; } // caching if the sequence exists $ cls = get_called_class ( ) ; $ name = self :: resolveSequenceName ( ) ; if ( array_key_exists ( $ cls , self :: $ _sequence_exists ) && array_key_exists ( $ name , self :: $ _sequence_exists [ $ cls ] ) ) { return true ; } $ rtn = false ; switch ( Driver :: $ name ) { case "oracle" : $ rtn = self :: _oracleSequenceExists ( $ name ) ; break ; case "postgresql" : $ rtn = self :: _postgresqlSequenceExists ( $ name ) ; break ; } // if exists, cache result if ( $ rtn ) { if ( ! array_key_exists ( $ cls , self :: $ _sequence_exists ) ) { self :: $ _sequence_exists [ $ cls ] = array ( ) ; } self :: $ _sequence_exists [ $ cls ] [ $ name ] = true ; } return $ rtn ; }
Check if a sequence exists

@return exists or not
Check if a sequence exists