Hibernate :QuerySyntaxException: AlertToEmployee.alert 未映射答案

【问题标题】：Hibernate :QuerySyntaxException: AlertToEmployee.alert is not mappedHibernate :QuerySyntaxException: AlertToEmployee.alert 未映射
【发布时间】：2019-10-18 13:14:51
【问题描述】：

我想创建一个包含两个类 Alert 和 AlertToEmployee 的连接查询，

班级警报：

public class Alert  {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    private String object;
    @Column(name = "is_deleted")
    private Boolean isDeleted = false;
}

类 AlertToEmployee

public class AlertToEmployee {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Enumerated(EnumType.STRING)
    private TypeAffectation typeAffectation;
    private String registrationNumber;
    private boolean isDeleted;
    @ManyToOne
    private Alert alert;
}

我创建了一个内部连接查询来获得具有特定条件的警报，但我对映射并不重要，我遇到了这个错误：QuerySyntaxException: AlertToEmployee.alert is not mapped

查询：

@Query( "SELECT new com.demo.shared.vo.AlertsVO(a.id,a.object  )" +
        "FROM  AlertToEmployee.alert a INNER JOIN  AlertToEmployee ate   ON a.id = ate.id WHERE a.isDeleted = false" +
        "  AND ate.registrationNumber = ?1 AND ate.isDeleted = false ")

我也试过这个，但它也不起作用：

@Query( "SELECT new com.demo.shared.vo.AlertsVO(a.id,a.object  )" +
        "FROM  Alert a INNER JOIN  AlertToEmployee ate   ON a.id = ate.id WHERE a.isDeleted= false" +
        "  AND ate.registrationNumber = ?1 AND ate.isDeleted = false ")

请帮忙。

【问题讨论】：

标签： java mysql sql spring hibernate

【解决方案1】：

您不必执行 INNER JOIN。你的查询应该是这样的：

@Query("SELECT new com.demo.shared.vo.AlertsVO(ate.alert.id, ate.alert.object) " +
       "FROM  AlertToEmployee ate " +
       "WHERE ate.registrationNumber = ?1 AND ate.alert.isDeleted = false")

【讨论】：