MYSQL，多列分组

Question

我有两张桌子。 示例数据查询：cmadjprice：

select symbol,close,timestamp from cmadjprice;
ABCD,815.9,2014-10-31
ABCD,808.85,2014-11-03
ABCD,797.4,2014-11-05
ABCD,776.55,2014-11-07
ABCD,800.85,2014-11-10
ABCD,808.9,2014-11-11
ABCD,826.8,2014-11-12
ABCD,856.45,2014-11-13
ABCD,856.65,2014-11-14

BB03表输出示例查询

select symbol,enter_dt,enter_price,exit_dt,exit_price from bb03 ;
ABCD,2014-10-31,815.90,2018-07-27,1073.60

我正在寻找同一日期的最高收盘价。

select a.symbol, max(a.close) ,a.timestamp  from  cmadjprice a
inner join BB03 b on a.symbol = b.symbol
where a.timestamp between b.enter_dt and b.exit_dt
group by a.symbol,a.timestamp;

没有得到输出？ 请帮助解决这个预期输出

ABCD,2014-10-31,815.90,2018-07-27,1073.60,856.65,2014-11-14;

Answer 1

试试下面：

select a.symbol, max(cast(a.close as DECIMAL(5,2)))  from  cmadjprice a
inner join BB03 b on a.symbol = b.symbol
where a.timestamp between b.enter_dt and b.exit_dt
group by a.symbol;

Answer 2

我认为这就是你需要的：
请注意，如果最大收盘价在与给定交易品种相关的时间戳序列中出现不止一次，这可能会返回多个记录

select c.symbol, c.maxval, d.timestamp from 
(
select 
a.symbol, 
max(a.close) as maxval 
from  
cmadjprice a
inner join BB03 b 
on a.symbol = b.symbol 
where a.timestamp between b.enter_dt and b.exit_dt
group by a.symbol
) c
inner join
cmadjprice d
on c.symbol = d.symbol and c.maxval = d.close
;