* 겪고 있는 문제 상황을 최대한 자세하게 작성해주세요.

* 문제 해결을 위해 어떤 시도를 해보았는지 구체적으로 함께 알려주세요.

오류의 원인이 모르겠습니다. 제대로 작성한 것 같은데,,, 어디가 잘못 된 걸까요?

CREATE TABLE IF NOT EXISTS MAJOR
(
    major_code varchar(100) primary key comment '주특기코드',
    major_name varchar(100) not null comment '주특기명',
    tutor_name varchar(100) not null comment '튜터'
);

CREATE TABLE IF NOT EXISTS STUDENT
(
    student_code varchar(100) primary key comment '수강생코드',
    name varchar(100) not null comment '이름',
    birth varchar(8) null comment '생년월일',
    gender varchar(1) not null comment '성별',
    phone varchar(11) null comment '전화번호',
    major_code varchar(100) not null comment '주특기코드',
    foreign key(major_code) references major(major_code)
);

CREATE TABLE IF NOT EXISTS EXAM
(
    student_code varchar(100) not null comment '수강생코드',
    exam_seq int not null comment '시험주차',
    score decimal(10,2) not null comment '시험점수',
    result varchar(1) not null comment '합불'
);


# 문제 1
CREATE TABLE IF NOT EXISTS MANAGER
(
    id bigint primary key,
    name varchar(100) not null,
    student_code varchar(100) not null,
    CONSTRAINT manager_fk_student_code foreign key(student_code) references student(student_code)
);

# 문제2
ALTER TABLE MANAGER MODIFY COLUMN id bigint auto_increment;

# 문제3
INSERT INTO MANAGER(name, student_code) VALUES('managerA', 's1');
INSERT INTO MANAGER(name, student_code) VALUES('managerA', 's2');
INSERT INTO MANAGER(name, student_code) VALUES('managerA', 's3');
INSERT INTO MANAGER(name, student_code) VALUES('managerA', 's4');
INSERT INTO MANAGER(name, student_code) VALUES('managerA', 's5');

INSERT INTO MANAGER(name, student_code) VALUES('managerB', 's6');
INSERT INTO MANAGER(name, student_code) VALUES('managerB', 's7');
INSERT INTO MANAGER(name, student_code) VALUES('managerB', 's8');
INSERT INTO MANAGER(name, student_code) VALUES('managerB', 's9');

오류 메시지

[2025-07-19 00:13:59] [23000][1452] Cannot add or update a child row: a foreign key constraint fails (`assignment`.`manager`, CONSTRAINT `manager_fk_student_code` FOREIGN KEY (`student_code`) REFERENCES `student` (`student_code`))