oracle触发编译错误

Question

对于以下触发器，我收到以下编译错误：缺少 SET 关键字，忽略 SQL 语句（在第 2 行），在预期以下情况之一时遇到符号“文件结尾”：（开始案例声明结束goto 异常退出 if loop mod null pragma raise return select update while with

CREATE OR REPLACE TRIGGER CHANGE_RENTAL_RATE
BEFORE INSERT ON film FOR EACH ROW
BEGIN
UPDATE film
SELECT *
SET rental_rate = CASE special_features
              WHEN 'Trailers' THEN rental_rate := :new.rental_rate + 0.1
              WHEN 'Commentaries' THEN rental_rate := new.rental_rate + 0.5
              WHEN 'Deleted Scenes' THEN rental_rate := new.rental_rate + 0.2
              WHEN 'Behind the Scenes' THEN rental_rate := new.rental_rate - 0.2
END;
/

Answer 1

您的更新语句没有意义，因为它影响了film 中的所有行。您正在执行“之前”触发器。也许你想要：

CREATE OR REPLACE TRIGGER CHANGE_RENTAL_RATE
BEFORE INSERT ON film FOR EACH ROW
BEGIN
    if :new.special_features = 'Trailers' THEN :new.rental_rate := :new.rental_rate + 0.1;
    elsif :new.special_features = 'Commentaries' THEN :new.rental_rate := :new.rental_rate + 0.5;
    elsif :new.special_features = 'Deleted Scenes' THEN :new.rental_rate := :new.rental_rate + 0.2;
    elsif :new.special_features = 'Behind the Scenes' THEN :new.rental_rate := :new.rental_rate - 0.2;
    else :new.special_features := NULL
    end if;
END;