多条联查，查询每个月的数据，按月份分组查询

通过 A.id =B.Id 查询B.data ,然后根据date 查出每个月的数据个数 counts

select count(*) as counts,data
from(
SELECT SUBSTR(B.addDate FROM 1 FOR 7) as data
FROM B
INNER JOIN A
ON A.vehicleId = B.vehicleId

)as tt
group by data
ORDER BY data desc
LIMIT 1,10

疑问：
from(
SELECT SUBSTR(B.addDate FROM 1 FOR 7) as data
FROM B
INNER JOIN A
ON A.vehicleId = B.vehicleId

)as tt
没有取别名的话 ，会报错

SUBSTR(B.addDate FROM 1 FOR 7)
sql 中字符串截取