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Mysql 按最新值sql分组_Mysql_Sql - Fatal编程技术网

Mysql 按最新值sql分组

Mysql 按最新值sql分组,mysql,sql,Mysql,Sql,我有一个如上所述的数据框架,当更多数据可用时,预测会在特定日期持续出现 我想分别获得每个对象和组的需求和供应在特定日期的最新预测值 Forecast date date Value Object Demand or supply 01-01-2016 00:30 12-10-2019 00:00 85 Ice-cream Demand 04-07-2018 02:59 26-12-2019 00:00 83

我有一个如上所述的数据框架,当更多数据可用时,预测会在特定日期持续出现

我想分别获得每个对象和组的需求和供应在特定日期的最新预测值

Forecast date            date          Value  Object     Demand or supply
01-01-2016 00:30    12-10-2019 00:00    85    Ice-cream     Demand
04-07-2018 02:59    26-12-2019 00:00    83    Crisps        Supply
07-08-2018 03:25    29-02-2020 00:00    50    Juice         Demand
29-10-2018 03:25    09-05-2020 00:00    76    Juice         Supply
25-02-2019 03:25    07-08-2020 00:00    74    Juice         Demand
01-07-2019 03:25    11-10-2020 00:00    69    Crisps        Demand
17-10-2019 03:25    17-12-2020 00:00    77    Meal          Supply
06-01-2020 03:25    29-03-2021 00:00    87    Eggs          Demand
期望输出

Logic-
-Latest forecast date for each date value and object
- Group demand/supply and object with Date desc
因此,为了使日期栏中的条目更加清晰 -我希望该值是最新预测日期中的值。
-然后按需求/供应对表进行分组,然后按对象分组,最后按日期分组,从而在需求/供应端为每个对象获取相应的时间序列值


@草莓添加了MRE和一个解释,很抱歉没有早点做!我看不出来。嗨,戈登,你能看看这个问题的编辑吗
Forecast Date   Date    Demand or supply    Object  Value
01-01-2020  01-11-2021  Demand            Ice-Cream 60
01-01-2020  01-10-2021  Demand            Ice-Cream 80
01-01-2020  01-09-2021  Demand             Crisps   70
01-01-2020  01-08-2020  Supply             Crisps   70
01-11-2019  01-07-2020  Supply             Crisps   85
01-11-2019  01-06-2020  Supply             Crisps   80
select t.*
from (select t.*,
             row_number() over (partition by object, demand_group, date order by forecast_date desc) as seqnum
      from t
     ) t
where seqnum = 1;