MySQL 获取连续范围，mysql获取范围

MySQL 获取连续范围，mysql获取范围

1、原始数据

2、把running_number转成数据，并加上一列有序数字

SELECT d.running_number+0 running_number,@a:=@a+1 rn FROM device_data d,(SELECT @a:=0) a 
where d.device_id=13 order by d.running_number;

3、running_number与有序数据的差，差(diff)相同的的running_number说明是连续的

SELECT running_number,rn,running_number-rn diff
FROM 
(SELECT d.running_number+0 running_number,@a:=@a+1 rn 
FROM device_data d,(SELECT @a:=0) a where d.device_id=13) b;

4、根据差来分组，并获得相关差的最小及最大running_number，就形成了连续范围

select min(c.running_number) min,max(c.running_number) max
from
(SELECT running_number,rn,running_number-rn diff
  FROM 
(SELECT d.running_number+0 running_number,@a:=@a+1 rn 
FROM device_data d,(SELECT @a:=0) a where d.device_id=13)
 b)c group by diff;

5、参考《MySQL技术内幕：SQL编程》 2.6.2连续范围问题