Spring Hibernate - 使用@Formula从基于其他表的最大值中获取列值答案

【问题标题】：Spring Hibernate - Fetch column value using @Formula from max value based of other tableSpring Hibernate - 使用@Formula从基于其他表的最大值中获取列值
【发布时间】：2021-01-22 19:01:25
【问题描述】：

我有两个具有一对多关系的表。铅和铅活动。一个潜在客户可以有多个活动。

问题陈述 - 我想在潜在客户表中增加一列来了解任何潜在客户的最后修改日期。上次修改日期将是上次创建或更新活动的日期。所以，我使用@Formula 来获取列。但是，我无法获得正确的日期，而是获得字段 lastModifiedDate 的空值。任何人都可以帮助我哪里出错。下面是表结构

@Entity
@Table(name = "customer_lead")
@Where(clause = ReusableFields.SOFT_DELETED_CLAUSE)
@Audited(withModifiedFlag = true)
@Data
public class Lead extends ReusableFields implements Serializable
{
    //other fields 

    @NotAudited
    @Formula("(Select max(modified) from lead_activity la Where la.lead_id=lead_id)")
    Date lastModifiedDate;
}

领导活动

@Entity
@Table(name = "LeadActivity")
@Data
@Where(clause = ReusableFields.SOFT_DELETED_CLAUSE)
public class LeadActivity extends ReusableFields implements Serializable
{
    // other fields

    @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
    @JoinColumn(name = "lead_id", nullable = false)
    @JsonIgnoreProperties(
    { "hibernateLazyInitializer", "handler" })
    @NotFound(action = NotFoundAction.IGNORE)
    Lead lead;

}

修改字段的映射超类

@MappedSuperclass
@Audited
public class ReusableFields implements Serializable
{

    public static final String SOFT_DELETED_CLAUSE = "is_deleted = 'false'";

    
    @Column(name="is_deleted", columnDefinition="BOOLEAN DEFAULT true")
    public boolean isDeleted;

    @CreationTimestamp
    @Column(name = "created_at")
    @JsonProperty("created")
    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern="yyyy-MM-dd HH:mm:ss ")
    private Date created;
    
    @Column(name = "updated_at")
    @JsonProperty("updated")
    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern="yyyy-MM-dd HH:mm:ss")
    @UpdateTimestamp
    private Date modified;
    
    public Date getCreated() {
        return created;
    }

    public void setCreated(Date created) {
        this.created = created;
    }

    public Date getModified() {
        return modified;
    }

    public void setModified(Date modified) {
        this.modified = modified;
    }

    public boolean isDeleted() {
        return isDeleted;
    }

    public void setDeleted(boolean isDeleted) {
        this.isDeleted = isDeleted;
    }

    public static String getSoftDeletedClause() {
        return SOFT_DELETED_CLAUSE;
    }
    
}

【问题讨论】：

标签： spring spring-boot hibernate spring-data-jpa spring-data

【解决方案1】：

通过添加以下公式来处理此问题

@NotAudited @Formula("(Select max(la.updated_at) from Lead_Activity la Where la.lead_id=lead_id)") 日期 lastModifiedDate;

【讨论】：