在日期范围内计数不同，运行 Grass_date

Question

我有一张这样的桌子：

date	name
1/1	a
1/2	b
1/3	c
1/2	a
1/3	d

并且需要从每行的日期开始计算 7 天内可用的不同名称。 结果应该是：

date	count	explain
1/1	1	a
1/2	2	a,b
1/3	4	a,b,c,d

我试过这些 count+if、count+case when、lag 函数：

• COUNT(DISTINCT(IF(date_1 between date - INTERVAL '7' DAY and date, name)))
• lag(count(distinct name), 7) over (order by date)

没有任何作用，结果只是每天计算的名字。

请指教，非常感谢！

Answer 1

嗯。 . .这符合您的要求吗？

select min_date, 
       sum(count(*)) over (order by date) as cnt,
       array_agg(array_agg(name)) over (order by date) as names
from (select name, min(date) as min_date
      from t
      group by name
     ) t
group by min_date;

编辑：

假设每个日期有一行，添加一个窗框规范：

select min_date, 
       sum(count(*)) over (order by date rows between 6 preceding and current row) as cnt,
       array_agg(array_agg(name)) over (order by date rows between 6 preceding and current row) as names
from (select name, min(date) as min_date
      from t
      group by name
     ) t
group by min_date