如何让Hibernate自动建表时，将集合类型存储为字符串？

2024-02-14 06:50:11

如果在您的Java实体类中，某个属性的数据类型为列表，您可能希望在数据库表中，该字段以VARCHAR类型创建表字段。

问题：

Hibernate自动建表失败，集合类型无法以字符串的形式入库。

解决办法：

使用@CollectionTable注解

@Entity
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @CollectionTable(name = "student_addresses", joinColumns = @JoinColumn(name = "student_id"))
    @Column(name = "address")
    private List<String> addresses;

    // getters and setters
}

使用@ElementCollection注解

@Entity
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @ElementCollection
    @CollectionTable(name = "student_addresses", joinColumns = @JoinColumn(name = "student_id"))
    @Column(name = "address")
    private List<String> addresses;

    // getters and setters
}

使用@JoinColumn注解

@Entity
public class Student {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    @OneToMany
    @JoinColumn(name = "student_id")
    private List<Address> addresses;

    // getters and setters
}

@Entity
public class Address {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String address;

    // getters and setters
}