Sql Oracle触发器创建时出现编译错误

我编写了下面的触发器，以防止用户在类日期与会话所在的星期几不匹配时将类分配给会话

CREATE OR REPLACE TRIGGER trig_alternative_classDate
AFTER INSERT OR UPDATE ON ALTERNATIVE
FOR EACH ROW
DECLARE
    classdate CHAR;
    sessionday VARCHAR;
BEGIN
    SELECT to_char(to_date(class.class_date), 'Day') INTO classdate, sessions.day INTO sessionday
    FROM SESSIONS, CLASS, DUAL, LOCATION, ALTERNATIVE
    WHERE class.class_id = alternative.class_id
    AND alternative.location_id = location.location_id
    AND sessions.location_id = location.location_id;
    IF sessions.day != to_char(to_date(class.class_date), 'Day')
    THEN raise_application_error(-20999,'Invalid Class Date - Class Date does not match Session Day');
    END IF;
END;
/

但是，当我运行触发器时，会收到一条错误消息

Warning: Trigger created with compilation errors.

SQL> show error trigger trig_alternative_classDate
Errors for TRIGGER TRIG_ALTERNATIVE_CLASSDATE:

LINE/COL ERROR
-------- -----------------------------------------------------------------
5/2  PL/SQL: SQL Statement ignored
5/80 PL/SQL: ORA-00923: FROM keyword not found where expected

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有人能帮忙吗？

删除第二个插入-只需要一个插入：

INTO classdate, sessions.day INTO sessionday

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@本·汤森-你试过了吗？作品