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用一個(gè)實(shí)例講解DB2數(shù)據(jù)庫游標(biāo)循環(huán)的問題
瀏覽:208日期:2023-11-08 19:30:31
本文中的存儲過程示例,預(yù)計(jì)的循環(huán)次數(shù)是yh表行數(shù),由于SELECT IID INTO PINT FROM YH WHERE 0=1;不返回任何行,所以at_end后會(huì)立刻等于1(只循環(huán)一次就退出)。
DECLARE at_end INT DEFAULT 0; DECLARE PIID INTEGER DEFAULT 0 ;DECLARE PINT INTEGER DEFAULT 0 ; DECLARE not_found CONDITION FOR SQLSTATE '02000';--DECLARE PCOUNT INTEGER;DECLARE c1 CURSOR FOR SELECT IID FROM YH; DECLARE CONTINUE HANDLER FOR not_found SET at_end = 1; OPEN c1; SET PCOUNT=0;ins_loop: LOOP FETCH c1 INTO PIID; IF at_end <>0 THEN LEAVE ins_loop; END IF; SET PCOUNT=PCOUNT+1;SELECT IID INTO PINT FROM YH WHERE 0=1;END LOOP;
標(biāo)簽:
DB2
數(shù)據(jù)庫
排行榜
