SpringBoot+mybatis查询灵异事件！

今天写公司项目中，遇到一个很奇怪的灵异事情

如图！

 

 问题解决思路，先从controller ==> service ==> dao ==>mapper.xml 排查

问题发现在mapper.xml中有问题

我的原始*.xml是这样的写resultMap的

        
 
        
        
        
        
        
        
        
        
        

        
            
            
            
            
            
            
        

        
            
        

        
            
            
        


    



    
    
      SELECT
	a.areaid AS areaid, Right(a.areaNo, 4) AS aareaNo, a.registeredNo AS aregisteredNo,
	a.name AS aname,concat_ws('_',n.name,a.addr) AS aaddr,
	case a.DS when 'S' then '单月' else '双月' end AS ads,
	 COUNT(m.meterid) AS mmeterid,
	 SUM(m.TH_NUMBER) AS mTH_NUMBER,
	 SUM(m.S_NUMBER) AS mS_NUMBER,
	 t.n AS atnNumber,
	 a.reserved AS areserved,
	 to_char(GREATEST(m.TH_R_TIME),'YYYY-MM-DD hh:mm:ss') AS mTH_R_TIME,
	 to_char(a.lastsumday,'YYYY-MM-DD hh:mm:ss') AS alastsumday,
	 to_char(LEAST(m.starttime),'YYYY-MM-DD') AS mstarttime, a.description AS adescription
	 FROM ((ha_area a LEFT JOIN ha_meter m ON m.areaid=a.areaid)
	 LEFT JOIN ha_rgn n ON n.id=Left(a.areaNo, 1))
	 LEFT JOIN (SELECT Count(i.meterid) AS n,i.areaid AS areaid
	 FROM hav_meterinfo i WHERE i.状态!='正常' AND i.状态!='正确' AND i.状态!='建档'
	 AND i.状态!='集中器无返回' AND i.状态!='关阀' AND i.状态!='修改' AND i.状态!='已更正'
	 AND i.状态!='已更换' AND i.状态!='采集器无返回' AND i.状态 NOT LIKE '%用量异常%'
	  AND i.表号 >0
	 GROUP BY i.areaid) t ON t.areaid=a.areaid
	group by a.areaid,a.areaNo,a.registeredNo,a.name,n.name,a.addr,a.DS,t.n,
	a.reserved,m.TH_R_TIME,
	a.lastsumday,m.starttime,a.description
    

估计在看的各位老鸟立马就能观察出来，没错就是你想的，

原因：

1.有中文 可能会出现乱码

2.查询语句和xml中的字段没有映射对

解决步骤，

1.去掉中文，把不需要的删掉；

2.把一些用聚合函数的取一个英文别名，和实体类的属性相等，没有的就给加上

最终解决完~

    
        
        
        
        
        
        
        
        
        
        

        
            
            
            
            
            
            
        




    




    
    
      SELECT
	a.areaid AS areaid, Right(a.areaNo, 4) AS aareaNo, a.registeredNo AS aregisteredNo,
	a.name AS aname,concat_ws('_',n.name,a.addr) AS aaddr,
	case a.DS when 'S' then '单月' else '双月' end AS ads,
	 COUNT(m.meterid) AS mmeterid,
	 SUM(m.TH_NUMBER) AS mTH_NUMBER,
	 SUM(m.S_NUMBER) AS mS_NUMBER,
	 t.n AS atnNumber,
	 a.reserved AS areserved,
	 to_char(GREATEST(m.TH_R_TIME),'YYYY-MM-DD hh:mm:ss') AS mTH_R_TIME,
	 to_char(a.lastsumday,'YYYY-MM-DD hh:mm:ss') AS alastsumday,
	 to_char(LEAST(m.starttime),'YYYY-MM-DD') AS mstarttime, a.description AS adescription
	 FROM ((ha_area a LEFT JOIN ha_meter m ON m.areaid=a.areaid)
	 LEFT JOIN ha_rgn n ON n.id=Left(a.areaNo, 1))
	 LEFT JOIN (SELECT Count(i.meterid) AS n,i.areaid AS areaid
	 FROM hav_meterinfo i WHERE i.状态!='正常' AND i.状态!='正确' AND i.状态!='建档'
	 AND i.状态!='集中器无返回' AND i.状态!='关阀' AND i.状态!='修改' AND i.状态!='已更正'
	 AND i.状态!='已更换' AND i.状态!='采集器无返回' AND i.状态 NOT LIKE '%用量异常%'
	  AND i.表号 >0
	 GROUP BY i.areaid) t ON t.areaid=a.areaid
	group by a.areaid,a.areaNo,a.registeredNo,a.name,n.name,a.addr,a.DS,t.n,
	a.reserved,m.TH_R_TIME,
	a.lastsumday,m.starttime,a.description
    

另外补充一下，我在查询中，除了表还有视图一起用，可以把视图当场一个表用这里不多说，具体可以参看

Mybatis中视图的使用

如果博文中有什么不对的地方，请各位老鸟多多指教

如果上面用到的方法，没有帮到你的话，那就是你的类映射错了，仔细检查是在你当前的类映射还是，应该在别的类映射