表A:如何查询子类别
name | date | con
------------------------------
tv | 2017-07-01 | 1
tv | 2017-07-02 | 1
tv | 2017-07-03 | 1
tv | 2017-07-03 | 2
mobil | 2017-07-03 | 1
mobil | 2017-07-04 | 1
tablet | 2017-07-03 | 1
tablet | 2017-07-03 | 2
tablet | 2017-07-03 | 3
tableB的:
name | date | was
------------------------------
tv | 2017-07-01 | 15
mobil | 2017-07-03 | 50
mobil | 2017-07-04 | 15
tablet | 2017-07-04 | 30
结果表A(没问题):
select name,
Group_concat(cons) as conA
from(
select name,
count(con) as cons
from tableA
where
date between '2017-07-01' and '2017-07-31'
GROUP BY con, name
HAVING con>0) q
GROUP BY name;
如何tableA
结合210 tableB
? 左加入 - >我没有尝试? 子类别 - >我没有尝试? 我应该怎么办
所需的输出:
name | conA | wasB |
------- -------- --------
tv | 3,1 | 15 |
mobil | 4 | 65 |
tablet | 9,1,1 | 30 |
请更有可读性问题 –