Question

CREATE OR REPLACE TRIGGER "MY_TRIGGER2" 
     BEFORE INSERT ON "FILM" 
     FOR EACH ROW 
    BEGIN
            IF :NEW.RATING = 'G'
                    THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST - .10
          AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Recommended for all audiences';
                    END IF;
      IF :NEW.RATING = 'PG'
                    THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST + .20
          AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Parental guidance for young viewers';
                    END IF;
            IF :NEW.RATING = 'PG-13'
                    THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST + .20
          AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Parental guidance for young viewers';
                    END IF;
      IF :NEW.RATING = 'R'
                    THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST + .60
          AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Recommnded for mature audiences';
                    END IF;
      IF :NEW.RATING = 'NC-17'
                    THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST + 1.0
          AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Mature audiences only';
                    END IF; 
    END;
    /

我有这个，但concat部分抛出错误。有什么建议吗？

Answer 1

:NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Mature audiences only';

我在那个（或任何其他）concat行的末尾^（1）上看不到右括号。这几乎肯定是语法错误。

^（1）在分号之前，很明显。

Answer 2

此代码：

        IF :NEW.RATING = 'G'
                THEN :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST - .10
      AND :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Recommended for all audiences';
                END IF;

很奇怪。除了缺少的人之外，不要使用AND进行分配。所以：

        IF :NEW.RATING = 'G' THEN
            :NEW.REPLACEMENT_COST := :NEW.REPLACEMENT_COST - .10;
            :NEW.DESCRIPTION := CONCAT(:NEW.DESCRIPTION, 'Recommended for all audiences');
        END IF;

您需要修复其余代码。

SQL Trigger无法使用concat工作

2 个答案: