# 中繼器
###### tags: `CTBC-Lab2`


AuditingEntityListener.class

* CourseBean

@ManyToOne(cascade = CascadeType.MERGE)
@JoinColumn(name = "categoryID")

* CourseCategoryBean

@JsonIgnore // 加在屬性上，避免無窮迴圈
@OneToMany(fetch = FetchType.EAGER, mappedBy = "courseCategoryBean")

* 宏毅哥的解法

public CourseCategoryBean getCourseCategoryBean() {
    if(Objects.isNull(courseCategoryBean)) {
        return null;
    }
    CourseCategoryBean r = new CourseCategoryBean();
    r.setCategoryId(courseCategoryBean.getCategoryId());
    r.setCategoryName(courseCategoryBean.getCategoryName());
    r.setDetail(courseCategoryBean.getDetail());
    return r;
}

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* 資料庫 id ??

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