People.java
 
@Entity
public class People {
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false)
    private Long id;//id
 
    @Column(name = "name", nullable = true, length = 20)
    private String name;//姓名
 
    @Column(name = "sex", nullable = true, length = 1)
    private String sex;//性別
 
    @Column(name = "birthday", nullable = true)
    private Timestamp birthday;//出生日期
 
    @OneToOne(cascade=CascadeType.ALL)//People是關(guān)系的維護(hù)端，當(dāng)刪除 people，會級聯(lián)刪除 address
    @JoinColumn(name = "address_id", referencedColumnName = "id")//people中的address_id字段參考address表中的id字段
    private Address address;//地址 
}

Address.java
 
@Entity
public class Address {
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false)
    private Long id;//id
 
    @Column(name = "phone", nullable = true, length = 11)
    private String phone;//手機(jī)
 
    @Column(name = "zipcode", nullable = true, length = 6)
    private String zipcode;//郵政編碼
 
    @Column(name = "address", nullable = true, length = 100)
    private String address;//地址
 
    //如果不需要根據(jù)Address級聯(lián)查詢People，可以注釋掉
//    @OneToOne(mappedBy = "address", cascade = {CascadeType.MERGE, CascadeType.REFRESH}, optional = false)
//    private People people;
}

People.java
 
@Entity
public class People {
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false)
    private Long id;//id
 
    @Column(name = "name", nullable = true, length = 20)
    private String name;//姓名
 
    @Column(name = "sex", nullable = true, length = 1)
    private String sex;//性別
 
    @Column(name = "birthday", nullable = true)
    private Timestamp birthday;//出生日期
 
    @OneToOne(cascade=CascadeType.ALL)//People是關(guān)系的維護(hù)端
    @JoinTable(name = "people_address",
            joinColumns = @JoinColumn(name="people_id"),
            inverseJoinColumns = @JoinColumn(name = "address_id"))//通過關(guān)聯(lián)表保存一對一的關(guān)系
    private Address address;//地址 
}

Author.java
 
@Entity
public class Author { 
    @Id // 主鍵
    @GeneratedValue(strategy = GenerationType.IDENTITY) // 自增長策略
    private Long id; //id
 
    @NotEmpty(message = "姓名不能為空")
    @Size(min=2, max=20)
    @Column(nullable = false, length = 20)
    private String name;//姓名
 
    @OneToMany(mappedBy = "author",cascade=CascadeType.ALL,fetch=FetchType.LAZY)
    //級聯(lián)保存、更新、刪除、刷新;延遲加載。當(dāng)刪除用戶，會級聯(lián)刪除該用戶的所有文章
    //擁有mappedBy注解的實(shí)體類為關(guān)系被維護(hù)端
     //mappedBy="author"中的author是Article中的author屬性
    private List<Article> articleList;//文章列表  
}

Article.java
 
@Entity
public class Article { 
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) // 自增長策略
    @Column(name = "id", nullable = false)
    private Long id;
 
    @NotEmpty(message = "標(biāo)題不能為空")
    @Size(min = 2, max = 50)
    @Column(nullable = false, length = 50) // 映射為字段，值不能為空
    private String title;
 
    @Lob  // 大對象，映射 MySQL 的 Long Text 類型
    @Basic(fetch = FetchType.LAZY) // 懶加載
    @NotEmpty(message = "內(nèi)容不能為空")
    @Size(min = 2)
    @Column(nullable = false) // 映射為字段，值不能為空
    private String content;//文章全文內(nèi)容 
 
    @ManyToOne(cascade={CascadeType.MERGE,CascadeType.REFRESH},optional=false)//可選屬性optional=false,表示author不能為空。刪除文章，不影響用戶
    @JoinColumn(name="author_id")//設(shè)置在article表中的關(guān)聯(lián)字段(外鍵)
    private Author author;//所屬作者  
}

User.java
 
@Entity
public class User { 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
 
    @NotEmpty(message = "賬號不能為空")
    @Size(min=3, max=20)
    @Column(nullable = false, length = 20, unique = true)
    private String username; // 用戶賬號，用戶登錄時(shí)的唯一標(biāo)識
 
    @NotEmpty(message = "密碼不能為空")
    @Size(max=100)
    @Column(length = 100)
    private String password; // 登錄時(shí)密碼
 
    @ManyToMany
    @JoinTable(name = "user_authority",joinColumns = @JoinColumn(name = "user_id"),
    inverseJoinColumns = @JoinColumn(name = "authority_id"))
    //1、關(guān)系維護(hù)端，負(fù)責(zé)多對多關(guān)系的綁定和解除
    //2、@JoinTable注解的name屬性指定關(guān)聯(lián)表的名字，joinColumns指定外鍵的名字，關(guān)聯(lián)到關(guān)系維護(hù)端(User)
    //3、inverseJoinColumns指定外鍵的名字，要關(guān)聯(lián)的關(guān)系被維護(hù)端(Authority)
    //4、其實(shí)可以不使用@JoinTable注解，默認(rèn)生成的關(guān)聯(lián)表名稱為主表表名+下劃線+從表表名，
    //即表名為user_authority
    //關(guān)聯(lián)到主表的外鍵名：主表名+下劃線+主表中的主鍵列名,即user_id
    //關(guān)聯(lián)到從表的外鍵名：主表中用于關(guān)聯(lián)的屬性名+下劃線+從表的主鍵列名,即authority_id
    //主表就是關(guān)系維護(hù)端對應(yīng)的表，從表就是關(guān)系被維護(hù)端對應(yīng)的表
    private List<Authority> authorityList; 
}

Authority.java
 
@Entity
public class Authority {
 
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
 
    @Column(nullable = false)
    private String name; //權(quán)限名
 
    @ManyToMany(mappedBy = "authorityList")
    private List<User> userList;
 
}

 
@SpringBootTest
@RunWith(SpringRunner.class)
public class UserRepositoryTest { 
 
    @Autowired
    private UserRepository userRepository;
 
    @Autowired
    private AuthorityRepository authorityRepository;
 
    @Test
    public void saveAuthority() {
        Authority authority = new Authority();
        authority.setId(1);
        authority.setName("ROLE_ADMIN");
        authorityRepository.save(authority);
    }
 
    @Test
    public void saveUser() {
        User user = new User();
        user.setUsername("admin");
        user.setPassword("123456");
        Authority authority = authorityRepository.findById(1).get();
        List<Authority> authorityList = new ArrayList<>();
        authorityList.add(authority);
        user.setAuthorList(authorityList);
        userRepository.save(user);
    } 
}

 
@SpringBootTest
@RunWith(SpringRunner.class)
public class UserRepositoryTest { 
 
    @Autowired
    private UserRepository userRepository;
 
    @Test
    public void deleteUser() {
        userRepository.deleteById(1L);
    } 
}