Spring Boot Hibernate将数据插入Postgres中的错误列

Question

初始情况：我有这两个实体，杂货清单和产品。

杂货清单：一个杂货清单可以有几种产品。

@Entity
@Table(name = "lists")
public class GroceriesList {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "list_id")
    private Long listId;

    @Column(name = "list_name")
    private String listName;


    @ManyToMany(cascade = CascadeType.MERGE)
    @JoinTable(name = "lists_products",
            joinColumns = @JoinColumn(name = "product_id", referencedColumnName = "list_id"),
            inverseJoinColumns = @JoinColumn(name = "list_id", referencedColumnName = "product_id")
    )
    private Set<Product> products;

}

产品：一个产品可以分配给多个杂货店

@Entity
@Table(name = "products")
public class Product {

    public enum Category {
        Dairy,
        Fruit,
        Vegetable,
        Meat,
        Grains
    }

    // Product ID Column, GenerationType.Identity refers to auto incr in Postgres
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "product_id")
    private Long productId;

    @Column(name = "product_name")
    private String productName;

    @Column(name = "product_vendor")
    private String productVendor;

    @Enumerated(EnumType.STRING)
    @Column(name = "product_category")
    private Category productCategory;

    @Column(name = "product_storedquantity")
    private Integer productStoredQuantity;

    @JsonIgnore
    @ManyToMany(mappedBy = "products")
    private List<GroceriesList> groceriesLists;
}

实体和关系存储在Postgres中的三个不同表中（一个用于列表，一个用于产品，一个用于关系映射表）。

映射表：映射表"lists_products"

示例产品：Id=4的示例产品

问题是：我正在尝试创建新的列表，这很有效。但是，正如您可以从映射表图像中看到的那样，Hibernate将ID插入到错误的列中。映射表中的list\u id当前正在获取product\u id，映射表中的product\u id正在获取list\u id。我已尝试更改列名的顺序

Answer 1

在咨询了弗拉迪米尔的解决方案后，它给了我一个想法，我解决了我的问题。问题出在@JoinColumn注释中，我认为“name=…”属性引用数据库中的列名。

@ManyToMany(cascade = CascadeType.MERGE)
@JoinTable(name = "lists_products",
        joinColumns = @JoinColumn(name = "product_id", referencedColumnName = "list_id"),
        inverseJoinColumns = @JoinColumn(name = "list_id", referencedColumnName = "product_id")
)
private Set<Product> products;

但是，该属性引用了Spring Boot中实体内部声明的变量，即listId

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "list_id")
private Long listId;

因此，@JoinTable注释的工作实现应该如下所示，其中“name=…”使用该变量名称：

@ManyToMany(cascade = CascadeType.MERGE)
@JoinTable(name = "lists_products",
        joinColumns = @JoinColumn(name = "listId", referencedColumnName = "list_id"),
        inverseJoinColumns = @JoinColumn(name = "productId", referencedColumnName = "product_id")
)
private Set<Product> products;