Question

当我尝试直接从spring数据查询结果到DTO类时，出现此错误

原因：java.lang.IllegalArgumentException：org.hibernate.QueryException：无法解析属性：test.dao.bean.Car的owner_name [选择新的test.dto.bean.CarOwners（c.owner_name，c。 owner_nid，c.owner_phone，c.driver_name，c.driver_nid，c.driver_phone）（来自test.dao.bean.Car c）在org.hibernate.internal.ExceptionConverterImpl.convert（ExceptionConverterImpl.java:133）〜[hibernate-core-5.2.17.Final.jar：5.2.17.Final] 在org.hibernate.internal.ExceptionConverterImpl.convert（ExceptionConverterImpl.java:157）〜[hibernate-core-5.2.17.Final.jar：5.2.17.Final] 在org.hibernate.internal.ExceptionConverterImpl.convert（ExceptionConverterImpl.java:164）〜[hibernate-core-5.2.17.Final.jar：5.2.17.Final] 在org.hibernate.internal.AbstractSharedSessionContract.createQuery（AbstractSharedSessionContract.java:670）〜[hibernate-core-5.2.17.Final.jar：5.2.17.Final] 在org.hibernate.internal.AbstractSessionImpl.createQuery（AbstractSessionImpl.java:23）〜[hibernate-core-5.2.17.Final.jar：5.2.17.Final] 在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）〜[na：1.8.0_152] 在sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）〜[na：1.8.0_152] 在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）〜[na：1.8.0_152] 在java.lang.reflect.Method.invoke（Method.java:498）〜[na：1.8.0_152] 在org.springframework.orm.jpa.ExtendedEntityManagerCreator $ ExtendedEntityManagerInvocationHandler.invoke（ExtendedEntityManagerCreator.java:350）〜[spring-orm-5.0.7.RELEASE.jar：5.0.7.RELEASE] 在com.sun.proxy。$ Proxy123.createQuery（未知来源）〜[na：na] 在org.springframework.data.jpa.repository.query.SimpleJpaQuery.validateQuery（SimpleJpaQuery.java:87）〜[spring-data-jpa-2.0.8.RELEASE.jar：2.0.8.RELEASE] ...省略了76个通用框架

这是我的查询

@Query("SELECT new test.dto.bean.CarOwners(c.owner_name, c.owner_nid, c.owner_phone, c.driver_name, c.driver_nid, c.driver_phone) FROM car c")
public List<CarOwners> findAllCarOwners();

这是DTO类：

test.dto.bean;

public class CarOwners{

private String owner_name;
private Long owner_nid;
private Integer owner_phone;
private String driver_name;
private Long driver_nid;
private Integer driver_phone;

 public CarOwners(String owner_name, Long owner_nid, Integer owner_phone, String driver_name, Long driver_nid, Integer driver_phone) {
        this.owner_name = owner_name;
        this.owner_nid = owner_nid;
        this.owner_phone = owner_phone;
        this.driver_name = driver_name;
        this.driver_nid = driver_nid;
        this.driver_phone = driver_phone;

    }

public String getOwner_name() {
    return owner_name;
}


public void setOwner_name(String owner_name) {
    this.owner_name = owner_name;
}


public Long getOwner_nid() {
    return owner_nid;
}


public void setOwner_nid(Long owner_nid) {
    this.owner_nid = owner_nid;
}


public Integer getOwner_phone() {
    return owner_phone;
}


public void setOwner_phone(Integer owner_phone) {
    this.owner_phone = owner_phone;
}


public String getDriver_name() {
    return driver_name;
}


public void setDriver_name(String driver_name) {
    this.driver_name = driver_name;
}


public Long getDriver_nid() {
    return driver_nid;
}


public void setDriver_nid(Long driver_nid) {
    this.driver_nid = driver_nid;
}


public Integer getDriver_phone() {
    return driver_phone;
}


public void setDriver_phone(Integer driver_phone) {
    this.driver_phone = driver_phone;
}
}

请帮助??

Answer 1

由于：java.lang.IllegalArgumentException： org.hibernate.QueryException：无法解析属性：owner_name 来自：test.dao.bean.Car

显然，select子句中的字段应引用映射实体（Car）的 Java属性名称，而不是DTO中的属性名称。

所以假设汽车是：

@Entity
@Table(name="car")
public class Car{


    @Column(name="owner_name")
    private String ownerName;

}

那你应该写：

@Query("SELECT new test.dto.bean.CarOwners(c.ownerName) FROM car c")

实际上，DTO字段的名称与如何编写@Query字符串无关。它仅与DTO构造函数参数和SELECT NEW子句中的字段之间的顺序匹配。您可以使用任何DTO名称，只要它们的顺序和数据类型匹配即可。

直接向DTO查询结果

1 个答案: