jpa 找不到能够从类型X转换为类型Y的转换器

olmpazwi 于 9个月前发布在其他

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我面对这个错误

No converter found capable of converting from type [java.lang.Integer] to type [@org.springframework.data.jpa.repository.Query com.kevcode.saludxi.citasmcs.models.entity.Appointment]

字符串
当我尝试在方法中使用@Query时。

方法：

@Query("SELECT a.id, a.appointmentDate, a.appointmentTypeId, at.name as appointmentTypeName, " +
            "a.feeValue, at.lengthInMinutes, a.medicId, a.patientId, a.symptomId" +
            " FROM Appointment a INNER JOIN AppointmentType at ON at.id = a.appointmentTypeId" +
            " WHERE a.appointmentDate >= ?1 AND a.appointmentDate <=  ?2 AND a.medicId = ?3")
    List<Appointment> findAllBetweenDateAndMedicId(Date maxDate, Date minDate, int medicId);

型

预约类

public class Appointment extends EntityBase {
    //private int id **extended from EntityBase**
    private int appointmentTypeId;
    private int symptomId;
    private int medicId;
    private int patientId;
    @Column(name="appointmet_date")
    private LocalDateTime appointmentDate;
    private float feeValue;
    @Transient
    private int lengthInMinutes;
    @Transient
    private String appointmentTypeName;
}

型

Stacktrace：

org.springframework.core.convert.ConversionFailedException: Failed to convert from type [java.lang.Object[]] to type [@org.springframework.data.jpa.repository.Query com.kevcode.saludxi.citasmcs.models.entity.Appointment] for value '{78532, 2022-05-24 00:46:14.0, 2, Examen, 3000.0, 30, 61, 21, 41}'; nested exception is org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.Integer] to type [@org.springframework.data.jpa.repository.Query com.kevcode.saludxi.citasmcs.models.entity.Appointment]

型

jpa

来源：https://stackoverflow.com/questions/72356070/no-converter-found-capable-of-converting-from-type-x-to-type-y

2条答案

按热度按时间

46qrfjad1#

一个快速的解决方案是，由于您无法直接返回Appointment基础实体，因为您正在请求似乎是未Map的值，因此可以使用构造函数查询让JPA返回POJO而不是托管实体：

@Query("SELECT new package.Appointment(a.id, a.appointmentDate, a.appointmentTypeId, at.name, " +
            "a.feeValue, at.lengthInMinutes, a.medicId, a.patientId, a.symptomId)" +
            " FROM Appointment a INNER JOIN AppointmentType at ON at.id = a.appointmentTypeId" +
            " WHERE a.appointmentDate >= ?1 AND a.appointmentDate <=  ?2 AND a.medicId = ?3")

字符串
然后，您需要Appointment类中的构造函数，它以查询中使用的相同顺序（和类型）接受所有这些值：

public class Appointment extends EntityBase {
    //private int id **extended from EntityBase**
    private int appointmentTypeId;
    private int symptomId;
    private int medicId;
    private int patientId;
    @Column(name="appointmet_date")
    private LocalDateTime appointmentDate;
    private float feeValue;
    @Transient
    private int lengthInMinutes;
    @Transient
    private String appointmentTypeName;
    public Appointment(int id, LocalDateTime appointmentDate, int appointmentTypeId, String appointmentTypeName, float feeValue, int lengthInMinutes, int medicId, int patientId, int symptomId){
      this.setId(id);
      this.appointmentDate = appointmentDate;
      ..
    }
}

型
请记住，以这种方式获取的Appointment示例不是由JPA管理的，因此对它们的更改不会被跟踪和同步到数据库。您可能最好使用一个单独的视图对象，反映这个“appointment”数据实际上是appointment和AppointmentType数据，尽管我不确定为什么您不应该让Appointment拥有对Appointment Type的ManyToOne引用：

public class Appointment extends EntityBase {
  ..
  @ManyToOne
  @JoinColumn(name="appointmentTypeId")
  private AppointmentType appointmentType;
}

型
允许它与注解一起发送，因此类型名称，lengthInMinutes和任何其他属性总是可访问的-或者根据需要延迟获取。

赞(0）回复(0）举报 9个月前

xghobddn2#

我知道这已经很老了，但是.

赞(0）回复(0）举报 9个月前

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jpa 找不到能够从类型X转换为类型Y的转换器

2条答案

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