表table_01 里面有两个字段 col1，col2，分别代表“店铺”、“购买时间”我想按店铺统计，本月购买的人当中，是2018和2017年老顾客的人数
- select b.count as 2018年人数, c.count as 2017年人数, a.col1 as 店铺 from table_01 aleft join (select count(1) as count, a.col1 as col1 from table_01 awhere exists (select 1 from table_01 b where a.id = b.id and date_format(a.col2,'%Y') = '2018') group by a.col1) bon a.col1 = b.col1left join (select count(1) as count, a.col1 as col1 from table_01 awhere exists (select 1 from table_01 b where a.id = b.id and date_format(a.col2,'%Y') = '2017') group by a.col1) con a.col1 = c.col1group by a.col1
请问我这种写法可以吗？有没有更简洁的写法？
我想要的效果是这样的
，能不count吗 iOS fly ~
iOS fly ~