如何在jpql jpa中返回具有多个和的映射？

如何解决如何在jpql jpa中返回具有多个和的映射？

这是我的查询

select SUM(d.day) as totalDay,SUM(d.month) as totalMonth from record d where d.userId = ?1
Integer getRecod(Long id);

由于查询未返回整数，因此会发生错误。我应该用整数代替什么？

解决方法

您应将Integer替换为Object[]：

Object[] getRecod(Long id);

因为SUM(d.day) as totalDay,SUM(d.month) as totalMonth返回数组中的两个long值

,

解决方案1： 使用totalDay和totalMonth创建一个模型，并创建一个所有args构造函数。

public class UserDataModel {
    Long totalDay;
    Long totalMonth;

    public UserDataModel(Long totalDay,Long totalMonth) {
        this.totalDay = totalDay;
        this.totalMonth = totalMonth;
    }
    
    //getter and setter
}

将查询更改为

@Query(value = "select 
new com.package.UserDataModel(SUM(d.day) as totalDay,SUM(d.month) as totalMonth) 
from Record d where d.userId = ?1 ")
    UserDataModel getRecord(Long id);

解决方案2：使用弹簧凸出。创建一个这样的界面。确保遵循正确的camcelCase。

public interface UserDataModelV2 {
    Long getTotalDay();
    Long getTotalMonth();
}

像这样改变你的想法。

    @Query(value = "select " +
            " SUM(d.day) as totalDay,SUM(d.month) as totalMonth " +
            "from Record d where d.userId = ?1")
    List<UserDataModelV2> getRecord(Long id);

如果要返回HashMap而不是POJO，则可以使用hashMap扩展UserDataModel并将数据放入构造函数中的映射中。

public class UserDataModel extends HashMap<String,Object>{
    Long totalDay;
    Long totalMonth;

    public UserDataModel(Long totalDay,Long totalMonth) {
        this.totalDay = totalDay;
        this.totalMonth = totalMonth;
        put("totalDay",totalDay); 
        put("totalMonth",totalMonth); 
    }
    
    //getter and setter
}

或者您可以用Map 替换解决方案2中的接口。

@Query(value = "select " +
            " SUM(d.day) as totalDay,SUM(d.month) as totalMonth " +
            "from Record d where d.userId = ?1")
    List<Map<Stirng,Object>> getRecord(Long id);