Question

我有以下数据集

month | spend
Jan   | 100
Jan   | 200
Feb   | 10
Feb   | 500
Feb   | 100
March | 60

我希望每月汇总一次，如： -

Jan  | 300
Feb  | 910 // Spend till month of feb
March| 970 // Spend till month of March and so on...

我希望Sum明智地与前一个月的价值，我希望你理解。

Answer 1

drop table if exists t;
create table t (month text, spend int);
insert into t values 
("Jan",  100),
("Jan",  200),
("Feb",   10),
("Feb",  500),
("Feb",  100),
("March", 60);

select month, (@n:=@n + sum) sum 
    from 
      (select month, sum(spend) sum 
           from t 
         group by month 
         order by FIELD(MONTH,'Jan','Feb','March')
      ) t1 
    cross join 
     (select @n:=0) n

Answer 2

如果您的实际月份名称被MySQL理解（请查看DATE_FORMAT()），您也可以使用STR_TO_DATE('%b', month)来确定月份的顺序。然后

SELECT t1.month, SUM(t2.spend)
FROM mytable t1
INNER JOIN mytable t2 ON STR_TO_DATE('%b', t2.month) <= STR_TO_DATE('%b', t1.month)
GROUP BY t1.month

Mysql Rollup每天都有

2 个答案: