索引属于其他表的主键的键

问题描述

我有一张两张桌子一样的桌子

@Entity
 @Table(name = "product",uniqueConstraints=@UniqueConstraint(columnNames={"product_idn"}))
public class Product implements Serializable {
    private static final long serialVersionUID = 21409635044L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    private String product_idn;
}

另一个表

@Entity
@Table(name = "storage")
public class Storage implements Serializable {
    private static final long serialVersionUID = -67165579239L;

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

@ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "product_id",nullable = false)
    @JsonBackReference
    private Product product;
}

现在我正在从 storage 表中获取记录。应该在存储表的 product_id 上创建索引（非唯一）吗？我必须根据产品获取每个产品的存储计数/获取存储。

解决方法

只需添加@Index 注释，如下所示，它应该可以正常工作。

@Entity
@Table(name = "storage",indexes = @Index(columnList = "product_id",name = "storage_productId_index"))
public class Storage implements Serializable