警告：使用编译错误创建触发器。 （ORACLE

Question

我尝试创建一个触发器，检查教师是否已在此课程中教授此课程：

CREATE OR REPLACE TRIGGER C3
BEFORE INSERT ON classGroup
FOR EACH ROW
DECLARE teach NUMBER(10);
BEGIN
    SELECT count(*) INTO teach;
    from classGroup
    WHERE classId = :new.classId
    AND teacherId = :new.teacherId,
    AND sessionId = :new.sessionId;
        RAISE_APPLICATION_ERROR(-20002,'you cant teach 2 time the same class');

exception
    when no_data_found then
        -- do insert
END;
/

但我总是收到这条消息：

Warning: Trigger created with compilation errors.

表Classgroup包含：classId，groupId，sessionId，teacherId，desc

Answer 1

这是一个基本的语法错误。

有一个;教后和后，：new.teacherId

SELECT count(*) INTO teach
    from classGroup
    WHERE classId = :new.classId
    AND teacherId = :new.teacherId
    AND sessionId = :new.sessionId;