JPA / Hibernate选择查询返回重复记录 [英] JPA/Hibernate select query returning duplicate records

问题描述

我有一个表，比如，带有ID，State和User_ID的工具作为列。

I have a table ,say, Instrument with ID,State, and User_ID as columns.

所以我有这个JPA查询返回所有的仪器记录匹配
User_ID。

So I have this JPA query to return all the instrument records with a matching User_ID.

   query = manager.createQuery("SELECT instrument from Instrument instrument
             where instrument.User_ID=:User_ID",Instrument.class);
   query.setParameter("User_ID", User_ID);

   List<Instrument> instruments=  query.getResultList();

   for(Instrument instrument:instruments){
            System.out.println("Instrument ID  "+instrument.getID());
              // using sysout as it is not prod code yet
        }

它只返回第一条记录重复次数与匹配记录一样多次。

It is returning only the first record repeated as many times as there are matching records.

11:13:01,703 INFO  [stdout] (http-/127.0.0.1:8080-1) Instrument ID   1
11:13:01,704 INFO  [stdout] (http-/127.0.0.1:8080-1) Instrument ID   1
11:13:01,704 INFO  [stdout] (http-/127.0.0.1:8080-1) Instrument ID   1

I在Db中有三个记录，仪器ID为1,2,3和

I have three records in Db with instrument IDs 1,2, and 3

我在hibernate上启用了show sql查询，并且查询在数据库上直接运行
和返回不同的记录。

I enabled show sql query on hibernate and the query runs fine on the Database directly and returns distinct records.

Hibernate查询：

Hibernate Query:

    select instrumentjdo0_.User_ID as member_U1_0_, instrumentjdo0_.ID as ID2_0_, 
instrumentjdo0_.state as state4_0_ from instrument instrumentjdo0_ where instrumentjdo0_.User_ID=?

工具实体

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;




@Entity
@Table(name = "instrument")
public class Instrument{

    @Id
    @Column(name="User_ID", length=9, unique=true, nullable=false)
    String user_ID;

    @Column(name="ID",nullable=false)
    String ID;


    @Column(name="state",nullable=false)
    String state;

    public String getID() {
        return ID;
    }

    public void setID(String ID) {
        this.ID = ID;
    }

    public String getUserID() {
        return user_ID;
    }

    public void setUserID(String userID) {
        this.user_ID = userID;
    }


    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }
}

不确定我缺少什么。

推荐答案

问题是Instrument Entity中的错误列有 @ID 属性分配给它。

The issue was that the wrong column in the Instrument Entity had the @ID attribute assigned to it.

我从 User_ID 中删除​​了它并将其添加到 ID 并且工作正常。

I removed it from User_ID and Added it to ID and it worked fine.

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