小编hyn*_*iia的帖子

问：为什么 JPA Projection 无法转换Mysql bit(1)为Java Boolean？

Projection type must be an interface!当Mysqlbit(1)类型映射到Java类型时， Spring Jpa Projection出现错误Boolean。

Jpa 将实体类中的布尔列转换为 Mysql 表中的位（1）列。

如果我将getIsBasicPlanInfoProjection 接口中的类型更改Integer为Boolean，则不起作用。为什么会出现错误呢？

JPA 存储库

@Query(nativeQuery=true, value="select true as isBasic from dual")
ProductOrderDto.PlanInfoProjection findPlanInfoById(Long id);

投影接口

public class ProductOrderDto {

    @Getter
    public static class PlanInfo {
        private Boolean isBasic;

        public PlanInfo(PlanInfoProjection projection) {
            // this.isBasic = projection.getIsBasic(); //<-- I want to use like this.
            if (projection.getIsBasic() == …

I'm trying to call a @Cacheable method from within the same class.

And it didn't work. Because of:

In proxy mode (the default), only external method calls coming in through the proxy are intercepted. This means that self-invocation (in effect, a method within the target object that calls another method of the target object) does not lead to actual caching at runtime even if the invoked method is marked with @Cacheable. Consider using the aspectj mode in this case. Also, …

当我尝试更新插入测试数据（1,000 个实体）时，花了1m 5s。

所以我看了很多文章，然后我把处理时间减少到20秒。

但它对我来说仍然很慢，我相信有比我使用的方法更多的好的解决方案。有没有人有好的做法来处理这个问题？

我还想知道哪个部分使它变慢？

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1. 持久化上下文
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2. 附加选择
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谢谢你！

@实体类

该实体类是从用户手机中收集到用户步行步数的健康数据。

PK为userId和recorded_at（recorded_atPK来自请求数据）

@Getter\n@NoArgsConstructor\n@IdClass(StepId.class)\n@Entity\npublic class StepRecord {\n    @Id\n    @ManyToOne(targetEntity = User.class, fetch = FetchType.LAZY)\n    @JoinColumn(name = "user_id", referencedColumnName = "id", insertable = false, updatable = false)\n    private User user;\n\n    @Id\n    private ZonedDateTime recordedAt;\n\n    @Column\n    private Long count;\n\n    @Builder\n    public StepRecord(User user, ZonedDateTime recordedAt, Long count) {\n        this.user = user;\n …