P°φkaz UPDATE CURRENT OF

Kurzory v SQL

P°φkaz CLOSE

P°φkaz DELETE CURRENT OF (SQL)

p°φkaz_DELETE_CURRENT_OF ::= DELETE [ FROM tabulka ] WHERE CURRENT OF jmΘno_kurzoru;

P°φkaz DELETE CURRENT OF zruÜφ °ßdku, na nφ₧ je nastaven kurzor zadan² jmΘnem_kurzoru. JmΘno_kurzoru musφ b²t bu∩ deklarovßno v deklaraci_kurzoru nebo v p°φkazu FOR nebo musφ oznaΦovat dotaz pat°φcφ do aplikace a ulo₧en² v databßzi. Kurzor musφ umo₧≥ovat ruÜenφ zßznam∙.

Je-li v p°φkazu uvedena tabulka, musφ to b²t (jedinß) tabulka zp°φstupn∞nß zadan²m kurzorem.

Pokud zadan² kurzor nenφ otev°en), nastane chybov² sqlstate 34000, pokud nenφ nastaven na n∞kter² °ßdek (nap°. je p°ed prvnφm nebo za poslednφm °ßdkem), nastane chybov² sqlstate 24000. Je-li p°φkaz proveden v transakci READ ONLY, nastane chybov² sqlstate 25006.

P°φklad pou₧itφ:

Zm∞≥te cenu u polo₧ek cenφku takto: polo₧ky cenφku zaΦφnajφcφ na X sni₧te o 10%, zaΦφnajφcφ na A zvyÜte o 100%, ostatnφ sma₧te. Je to obdoba p°φkladu pou₧itΘho pro demonstraci p°φkazu FOR:

PROCEDURE ZmenaCeniku();
BEGIN 
  DECLARE err_notfound BIT DEFAULT FALSE;
  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' BEGIN SET err_notfound=TRUE; END;
  DECLARE curcen SENSITIVE CURSOR FOR 
    SELECT cislo_pol, cena
    FROM Cenik
  FOR UPDATE; 
  DECLARE Polozka CHAR(20); 
  DECLARE Cena NUMERIC(14,2); 
  OPEN curcen; 
  LabelLoop: LOOP 
     FETCH NEXT FROM curcen INTO Polozka, Cena; 
     IF err_notfound IS TRUE THEN LEAVE LabelLoop; END IF; 
     IF SUBSTRING(Polozka FROM 1 FOR 1) = "X" THEN 
       UPDATE SET Cena = Cena*0.9 WHERE CURRENT OF curcen;
     ELSEIF SUBSTRING(Polozka FROM 1 FOR 1) = "A" THEN 
       UPDATE SET Cena = Cena*2 WHERE CURRENT OF curcen;
     ELSE
       DELETE WHERE CURRENT OF curcen;
     END IF; 
  END LOOP LabelLoop; 
  CLOSE curcen; 
END;

Viz

• Kurzory v SQL

P°φkaz UPDATE CURRENT OF

Kurzory v SQL

P°φkaz CLOSE