java - OneToMany 无法确定 SpringBoot/SQLite3 的类型

Question

我的关系 oneToMany 有问题。我在 SQLite DB 中创建了表，这是我的表:我创建了两个模型 CategoryModel 和 ProductModel。产品型号为:

@Entity
@Table(name = "Product_Category")
@JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class ProductModel {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long product_id;
    private Long category_id;

    private String name;
    private String description;
    private int numberOfProduct;
    private String image;
    private int price;

    @JoinColumn(name = "country_id", nullable = false)
    private CategoryModel category;

    //geter's and seter's
}

我的类别模型:

@Entity
@Table(name = "Category")
@JsonIgnoreProperties({ "hibernateLazyInitializer", "handler" })
public class CategoryModel {
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;

    private String category_name;
    private String category_description;
    private String image_path;

    @OneToMany( mappedBy = "category")
    private Set<ProductModel> category;
  //Geter's and Seter's

我的存储库:

public interface CategoryRepository extends JpaRepository<CategoryModel, Long>  {

    @Query("SELECT * "
            + "FROM Product_Category d INNER JOIN d.categoryModel e")
    List<ProductModel> fetchEmpDeptDataInnerJoin();

}

我不明白我在哪里犯了错误。我有这个错误:

Could not determine type for: com.dar.darkozmetika.models.CategoryModel, at table: product_category, for columns: [org.hibernate.mapping.Column(category)]

Answer 1

1)添加@ManyToOne注释:

@ManyToOne
@JoinColumn(name = "country_id", nullable = false)
private CategoryModel category;

2) 请记住，您使用的是 JPQL，而不是 SQL(除非您发送 native="true"):

   @Query("SELECT p "
        + "FROM ProductModel p INNER JOIN p.category c")