索引属于其他表主键的键答案

【问题标题】：Indexing for key which belongs to Primary key of other table索引属于其他表主键的键
【发布时间】：2021-08-26 01:10:20
【问题描述】：

我有两个表作为表

@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。是否应该在存储表的 product_id 上创建索引（非唯一）？我必须根据产品获取存储数量/根据产品获取存储。

【问题讨论】：

标签： mysql hibernate jpa spring-data-jpa

【解决方案1】：

只需像下面这样添加 @Index 注释，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

【讨论】：