Question

我有以下表格。

create table Surveys ( 
    survey_id int, 
    cid int, 
    num_submitted int, 
    sum_q1 int, 
    sum_q2 int, 
    sum_q3 int, 
    sum_q4 int,
    constraint pk_survey primary key (survey_id),
    constraint fk_courses foreign key (cid) 
        references Courses(cid)
);

create table Surveydata ( 
    survey_id int,  
    sid int,
    submit_time date,
    q1 int, 
    q2 int, 
    q3 int, 
    q4 int, 
    q5_str varchar(250),
    constraint pk_survey_data primary key (survey_id, sid),
    constraint fk_sdata_surveys foreign key (survey_id) 
        references Surveys(survey_id),
    constraint fk_sdata_students foreign key (sid) 
        references Students(sid)
);

触发器

CREATE OR REPLACE TRIGGER survey_data_trigger
    AFTER INSERT OR UPDATE OR DELETE ON SURVEYDATA
    FOR EACH ROW

    BEGIN
        IF INSERTING THEN
            UPDATE Surveys SET
                num_submitted = num_submitted + 1, 
                sum_q1 = sum_q1 + :new.q1,
                sum_q2 = sum_q2 + :new.q2,
                sum_q3 = sum_q3 + :new.q3,
                sum_q4 = sum_q4 + :new.q4
            WHERE
                survey_id = :new.survey_id;
        END IF;

        IF UPDATING THEN
            IF(:new.survey_id = :old.survey_id) THEN
                UPDATE Surveys SET
                    sum_q1 = sum_q1 - :old.q1 + :new.q1,
                    sum_q2 = sum_q2 - :old.q2 + :new.q2,
                    sum_q3 = sum_q3 - :old.q3 + :new.q3,
                    sum_q4 = sum_q4 - :old.q4 + :new.q4
                WHERE
                    survey_id = :new.survey_id;
            ELSE
                UPDATE Surveys SET
                    num_submitted = num_submitted + 1, 
                    sum_q1 = sum_q1 + :new.q1,
                    sum_q2 = sum_q2 + :new.q2,
                    sum_q3 = sum_q3 + :new.q3,
                    sum_q4 = sum_q4 + :new.q4
                WHERE
                    survey_id = :new.survey_id; 

                UPDATE Surveys SET
                    num_submitted = num_submitted - 1, 
                    sum_q1 = sum_q1 - :old.q1,
                    sum_q2 = sum_q2 - :old.q2,
                    sum_q3 = sum_q3 - :old.q3,
                    sum_q4 = sum_q4 - :old.q4
                WHERE
                    survey_id = :old.survey_id;
                END IF;

        END IF;

        IF DELETING THEN
            UPDATE Surveys SET
                num_submitted = num_submitted - 1, 
                sum_q1 = sum_q1 - :old.q1,
                sum_q2 = sum_q2 - :old.q2,
                sum_q3 = sum_q3 - :old.q3,
                sum_q4 = sum_q4 - :old.q4
            WHERE
                survey_id = :old.survey_id;
        END IF;
    END;
/

当我发出时，

INSERT INTO Surveydata VALUES(1, 1, SYSDATE, 5, 5, 5, 5, 'Great teacher!');

触发器不会触发并更新此Surveydata记录所指向的调查记录。我在这里做错了什么？

Answer 1

你的触发器只有在它有效的情况下才会触发 - 也就是说，它是在没有错误的情况下创建的，并且从那时起就没有成功地停止它重新编译 - 并且已启用。您可以在user_objects表中检查有效性：

select status
from user_objects
where object_type = 'TRIGGER' and object_name = 'SURVEY_DATA_TRIGGER';

如果这表示触发器是INVALID，您可以看到它在user_errors表中有哪些错误：

select text
from user_errors
where type = 'TRIGGER' and name = 'SURVEY_DATA_TRIGGER'
order by sequence;

...然后使用更正的代码重新创建它。但是从this trigger seems to work开始，它可能对您有效，因此被禁用，您可以查看：

select status
from user_triggers
where trigger_name = 'SURVEY_DATA_TRIGGER';

如果说是DISABLED，则可以通过以下方式启用它：

alter trigger survey_data_trigger enable;

您的触发器创建代码不会将其创建为已禁用，因此如果它处于该状态，则可能是您有另一个明确禁用它的步骤。除非你有一个DDL触发器改变了所有新创建的触发器的状态，否则我想不出会自动禁用新触发器*的任何东西，但你可能知道这一点，你可以很容易地测试它。你似乎更有可能自己禁用它。

_{*好吧，有一个隐藏的初始化参数_system_trig_enabled，这会使它被创建为禁用，但是这个集合似乎也不太可能。}

Oracle触发器永远不会触发

1 个答案: