select dispatch_user_time,dispatch_areacode_time,acceptTime,last_update_time,distTime,
	CASE 
	WHEN (TIMESTAMPDIFF(HOUR,dispatch_areacode_time,dispatch_user_time)-acceptTime) >0 THEN '超时'
	WHEN (TIMESTAMPDIFF(HOUR,dispatch_areacode_time,dispatch_user_time)-acceptTime) <0 THEN '未超时'
	ELSE ''
END accept,
	CASE 
	WHEN (TIMEDIFF(last_update_time,ADDDATE(dispatch_areacode_time,INTERVAL distTime DAY))) > 0 THEN '超时'
	WHEN (TIMEDIFF(last_update_time,ADDDATE(dispatch_areacode_time,INTERVAL distTime DAY))) < 0 THEN '未超时'
	ELSE ''
END investigate
FROM test1 

　

详情见菜鸟教程高级函数教程

上图是从查询结果中进行判断运算，返回一个单独的列的值