使用 JPQL 通过连接表进行查询时出错

Question

我正在尝试使用彼此具有一对多关系的路线实体的源和目的地属性来获取列车实体列表。火车 table 将路线 ID 作为外键。 table 名称分别是路线和火车。请帮助我，因为查询正在抛出 java.lang.IllegalArgumentException: Validation failed for query for method public abstract java.util.List com.infyrail.app.repository.RouteRepository.findBySourceDestination(java.lang.String,java.lang.String)! 路线库：

public interface RouteRepository extends JpaRepository<RouteEntity, Integer> {
    @Query("SELECT t FROM train t JOIN route r WHERE r.source=?1 AND r.destination=?2")
    public List<TrainEntity> findBySourceDestination(String source,String destination);
}

路线实体：

@Entity
@Table(name="route")
public class RouteEntity {
     @Id              
     @GenericGenerator(name="route_id",
    strategy="com.infyrail.app.generator.RouteIdGenerator")
                @GeneratedValue(generator = "route_id")
    @Min(value = 100)
    @Max(value = 999)
    Integer id;

    String source;
    String destination;
    @OneToMany(mappedBy = "route",
            cascade=CascadeType.ALL,orphanRemoval = true)

    private List<TrainEntity> trainList;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getSource() {
        return source;
    }
    public void setSource(String source) {
        this.source = source;
    }
    public String getDestination() {
        return destination;
    }
    public void setDestination(String destination) {
        this.destination = destination;
    }
    public List<TrainEntity> getTrainList() {
        return trainList;
    }
    public void setTrainList(List<TrainEntity> trainList) {
        this.trainList = trainList;
    }

}

火车实体：

@Entity
@Table(name="train")
public class TrainEntity {

    //@GeneratedValue(strategy = GenerationType.IDENTITY)
     @Id              
     @GenericGenerator(name="train_id",
    strategy="com.infyrail.app.generator.TrainIdGenerator")
                @GeneratedValue(generator = "train_id")
    @Min(value = 100)
    @Max(value = 999)
    Integer id;
    String trainName;
    String arrivalTime;
    String departureTime;
    Double fare;
    @ManyToOne(fetch = FetchType.LAZY)
    @Autowired
    RouteEntity route;
    public RouteEntity getRoute() {
        return route;
    }
    public void setRoute(RouteEntity route) {
        this.route = route;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getTrainName() {
        return trainName;
    }
    public void setTrainName(String trainName) {
        this.trainName = trainName;
    }
    public String getArrivalTime() {
        return arrivalTime;
    }
    public void setArrivalTime(String arrivalTime) {
        this.arrivalTime = arrivalTime;
    }
    public String getDepartureTime() {
        return departureTime;
    }
    public void setDepartureTime(String departureTime) {
        this.departureTime = departureTime;
    }
    public Double getFare() {
        return fare;
    }
    public void setFare(Double fare) {
        this.fare = fare;
    }


}

Answer 1

问题来了。您的查询应该定义 table bean 名称而不是实际的 table 名称。

在你的情况下，你应该使用 TrainEntity 而不是 train 和 RouteEntity 而不是 route。

public interface RouteRepository extends JpaRepository<RouteEntity, Integer> {
    @Query("SELECT t FROM TrainEntity t JOIN RouteEntity r WHERE r.source=?1 AND r.destination=?2")
    public List<TrainEntity> findBySourceDestination(String source,String destination);
}

使用 JPQL 通过连接表进行查询时出错

Error while using JPQL to query by joining tables

java

spring

hibernate

join

jpql