Dobrý den.
Vďaka za skvelý seriál ,
Nedarí sa mi s nasledujúcim dotazom :

create procedure kniha_rozsah(OD int, ID int )
begin
declare device varchar(50);
set device = CONCAT('event','_',ID);
select *,from_unixtime(time) as t , device as U from device where `event` = OD LIMIT 5 ;
end

tabulky mam pomenovane ako event_[id] potrebujem do procedury pridat id ako vstupny parameter pre nasledovny select, zial neuspesne.

Ďakujem vopred za odpoveď.

V embeded SQL nesmi byt pouzita promenna jako nazev tabulky nebo sloupce. Na to musite pouzit tzv. dynamicke SQL http://rpbouman.blogspot.com/2005/11/mysql-5-prepared-statement-syntax-and.html

                    create procedure kniha_rozsah()
                    begin     
                        SET @tname = 'event_5676';
                        SET @s = 'select * from ? LIMIT 5';
                        
                        PREPARE stmt FROM @s ;                        
                        EXECUTE stmt USING @tname;
                        DEALLOCATE PREPARE stmt; 
                    end 

create procedure uplna( _t varchar(50) )
                BEGIN
                
                SET @table = _t;
                SET @s = CONCAT('SELECT * FROM ', @table , ' limit 10');
                
                PREPARE stmt3 FROM @s;
                EXECUTE stmt3;
                DEALLOCATE PREPARE stmt3;
                END