[Mini] 도서 관리 프로그램 - 3. 연관관계 설정

위 ERD를 기준으로 연관관계 설정

연관관계 포스팅은 여기

1.관계

1. Book -> Member (@ManyToOne, 단방향)
2. Book <-> History(양방향)
   • @OneToMany
   • @ManyToOne
3. History <-> Library(양방향)
   • @ManyToOne
   • @OneToMany

History는 교차 테이블 역할 수행

---

2.Entity

• Book

package com.mini.library.domain.Book.entity;

import com.mini.library.domain.History.History;
import com.mini.library.domain.Member.entity.Member;
import lombok.*;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
@Getter
@AllArgsConstructor
@NoArgsConstructor
@Builder
@ToString(exclude = {"member","bookHistoryList"})
public class Book {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long bid;

    private String bname;

    private String author;

    private String publisher;

    private boolean lend;

    @ManyToOne
    private Member member;

    @OneToMany(mappedBy = "book")
    private List<History> bookHistoryList = new ArrayList<>();

}

• History

package com.mini.library.domain.History;

import com.mini.library.domain.Book.entity.Book;
import com.mini.library.domain.Library.entity.Library;
import com.mini.library.global.auditable.Auditable;
import lombok.*;

import javax.persistence.*;

@Entity
@Getter
@ToString(exclude = {"book","library"})
public class History extends Auditable {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long hid;

    @ManyToOne
    @JoinColumn(name = "BOOK_ID")
    private Book book;

    @ManyToOne
    @JoinColumn(name = "LIBRARY_ID")
    private Library library;

}

• Library

package com.mini.library.domain.Library.entity;

import com.mini.library.domain.History.History;
import lombok.*;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity
@AllArgsConstructor
@NoArgsConstructor
@Builder
@Getter
@ToString(exclude = "libraryHistoryList")
public class Library {

    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long lid;

    private String lname;

    @OneToMany(mappedBy="library")
    private List<History> libraryHistoryList = new ArrayList<>();

}

• Member

package com.mini.library.domain.Member.entity;

import lombok.*;

import javax.persistence.*;

@Entity
@Getter
@AllArgsConstructor
@NoArgsConstructor
@Builder
@ToString
public class Member {
    @Id @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long mid;

    @Column
    private String mname;

    @Column(unique = true)
    private String phone;

    @Column
    private String password;

}