Question

我正在使用Hibernate（也是新的）并尝试使用聚合函数从MS SQL数据库中检索计数值和其他字段。我为数据创建了一个POJO类，如下所示：

package com.hdl.model.db;

import java.util.Date;


@Entity
@Table(name = "sfdc_stg_lab_orders")
@SqlResultSetMappings( {
SqlResultSetMapping(name = "ProfessorAndManager", 
columns = { @ColumnResult(name = "total"),
            @ColumnResult(name = "org_name"),
            @ColumnResult(name = "drawMonth"),
            @ColumnResult(name = "drawYear")
   })
})


public class OrgnameByMonthYear {

    public OrgnameByMonthYear(Id sfdc_stg_lab_order_key, String org_name,int drawMonth,    
  int drawYear , Double total){

        this.org_name = org_name;
        this.total = total;
        this.drawMonth = drawMonth;
        this.drawYear = drawYear;       
    }


    @Id
    @GeneratedValue
    @Column(name= "sfdc_stg_lab_order_key")
    /*
     * Unique ID - System Generated
     */
    private Integer sfdc_stg_lab_order_key; 

    /*
     * Name of the Organization
     */
    @Column(name= "org_name")
    private String org_name;

    @Column(name = "total")
    private double total;

    @Column(name = "drawMonth")
    private int drawMonth;

    @Column(name = "drawYear")
    private int drawYear;   


    public Integer getSfdc_stg_lab_order_key() {
        return sfdc_stg_lab_order_key;
    }

    public void setSfdc_stg_lab_order_key(Integer sfdc_stg_lab_order_key) {
        this.sfdc_stg_lab_order_key = sfdc_stg_lab_order_key;
    }   


    /**
     * @return the orgname
     */ 
    public String getOrg_name() {
        return org_name;
    }

        /**
     * @param orgname to set
     */
    public void setOrg_name(String org_name) {
         this.org_name = org_name;
    }   

    /**
     * @return the year
     */ 
    public double getTotal() {
        return total;
    }

    /**
     * @param total to set
     */
    public void setTotal(long total) {
        this.total = total;
    }   

    /**
     * @return the month
     */ 
    public int getDrawMonth() {
        return drawMonth;
    } 

    /**
     * @param month to set
     */
    public void setDrawMonth(int drawMonth) {
        this.drawMonth = drawMonth;
    }   

    /**
     * @return the year
     */ 
    public int getDrawYear() {
        return drawYear;
    }

    /**
     * @param year to set
     */
    public void setDrawYear(int drawYear) {
        this.drawYear = drawYear;
    }   


    @Override
    public String toString() {
        return "sfdc_stg_lab_orders [sfdc_stg_lab_order_key=" +    
  sfdc_stg_lab_order_key + "total=" + total + ", org_name=" + org_name + "]";
    }   
}

我正在使用Hibernate find调用以下内容来检索数据：

@SuppressWarnings("unchecked")
@Override   
public List<OrgnameByMonthYear> getOrgnameByMonthYear() {
    logger.info("Retrieving getOrgnameByMonthYear list inside SfdcStgLabOrdersDAOImpl ....");

        return hibernateTemplate.find("select count(org_name) AS total, org_name,  
month(specimen_draw_date_1) AS drawMonth, year(specimen_draw_date_1) AS drawYear from 
OrgnameByMonthYear group by org_name, month(specimen_draw_date_1), 
   year(specimen_draw_date_1)");
  }

我在Java中遇到以下错误“无法转换为OrgnameByMonthYear类”。提前感谢您的任何帮助！

org.springframework.scheduling.quartz.JobMethodInvocationFailedException: Invocation of method 'executeFirstTask' on target class [class com.hdl.service.impl.SchedulerService] failed; nested exception is java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.hdl.model.db.OrgnameByMonthYear at

org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean$MethodInvokingJob.executeInternal(MethodInvokingJobDetailFactoryBean.java:320) at 

org.springframework.scheduling.quartz.QuartzJobBean.execute(QuartzJobBean.java:113)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:223)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:549)

Caused by: java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to com.hdl.model.db.OrgnameByMonthYear

Answer 1

这可以通过创建一个包含查询结果的新类AggregationResults来完成：

public class AggregationResults {

    private Integer total;
    private String orgName;
    private Integer drawMonth;
    private Integer drawYear;

    ... constructor with all properties here ...
}

然后重写查询，以便使用AggregationResults运算符返回new：

@SuppressWarnings("unchecked")
@Override   
public List<AggregationResults> getOrgnameByMonthYear() {
    logger.info("Retrieving AggregationResults list inside SfdcStgLabOrdersDAOImpl ....");

        return hibernateTemplate.find("select new com.your.package.AggregationResults( count(org_name) AS total, org_name,  
month(specimen_draw_date_1) AS drawMonth, year(specimen_draw_date_1) AS drawYear) from 
OrgnameByMonthYear group by org_name, month(specimen_draw_date_1), 
   year(specimen_draw_date_1)");
  }

Hibernate无法使用聚合函数强制转换为Java

1 个答案: