如何在Spring启动中显示mysql视图？

Question

我有一个Spring Boot CRUD应用程序正在运行，只要我使用常规的MySQL表。但是我需要显示来自多个表的数据，所以我创建了一个MySQL视图。但是现在出现以下错误：

创建在类路径资源[org/spring framework/boot/auto configure/ORM/JPA/hibernate JPA configuration . class]中定义的名为“entityManagerFactory”的bean时出错:调用init方法失败；嵌套异常为org . hibernate . annotation exception:没有为实体指定标识符:net . tekknow . me daverter . domain . appointment view

我遵循了这个例子：https://www.javabullets.com/calling-database-views-from-spring-data-jpa/

以下是域对象:

package net.tekknow.medaverter.domain;

import java.io.Serializable;
import java.sql.Timestamp;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Table;
import javax.validation.constraints.Size;

@Entity
@Table(name = "vw_appointments")
public class AppointmentView implements Serializable {
    @Size(max = 32)
    @Column(name="Date")
    public String date;

    @Column(name="Physician")
    public String physician;

    @Column(name="LabCollected")
    public Timestamp labCollected;

    @Column(name="Note")
    public String note;

    public String getDate_time() {
        return date;
    }
    public String getPhysician() {
        return physician;
    }
    public Timestamp getDatetime_collected() {
        return labCollected;
    }
    public String getNote() {
        return note;
    }
}

下面是视图的mysql查询，只是为了向您展示它的工作原理:

关系型数据库

这是服务代码:

@Service
@Transactional
public class AppointmentViewService {

    @Autowired
    AppointmentViewRepository repo;

    public List<AppointmentView> listAll() {
        return repo.findAll();
    }      
}

下面是存储库代码:

public interface AppointmentViewRepository extends JpaRepository<AppointmentView,Integer> {}

Hibernate不处理视图吗？建议？

Answer 1

所有内容都在错误消息中说明：

没有为实体指定标识符:net . tekknow . med averter . domain . appointment view

设计视图，使其具有 1 列，可以使用@Id批注将其映射为实体的标识符字段。

您还可以将@org.hibernate.annotations.不可变注解添加到您的实体中，以确保HiberNate不会尝试传播您可以对您的实体所做的更改

@Entity
@Table(name = "vw_appointments")
// Prevent changes from being applied by Hibernate
@org.hibernate.annotations.Immutable
public class AppointmentView implements Serializable {
    // Identifier. Has to be Integer as you implement JpaRepository<AppointmentView,Integer>
    @Id
    @Column(name="Appointment_Id")
    private Integer appointmentId;

    public Integer getAppointmentId() {
        return this.appointmentId;
    }

    public void setAppointmentId(Integer appointmentId) {
        this.appointmentId = appointmentId;
    }

    // Public attributes ???. 
    // If it is not mandatory for technical reasons, prefer private attributes + getter/setter
    @Size(max = 32)
    @Column(name="Date")
    public String date;

    @Column(name="Physician")
    public String physician;
    ...
}