Mysql select 上周每天的总和

Question

I have a query in my report dashboard that shows me total of last 7 days income in one number.

Now I'm trying to get this number on a daily chart, for example:

April 7: 100,000 (total income from april 1 to 7)
April 8: 110,000 (total income from april 2 to 8)
...

How can I select like this?

Purchases table structure:

Value : int
Date : date

Answer 1

You can use window functions. If you have one row per day, this would often be used:

select t.*,
       sum(income) over (order by date rows between 6 preceding and current row)
from t;

This adds up 7 rows, so if there are missing or duplicate dates it is not correct.

However, range really does limit to the dates you want:

select t.*,
       sum(income) over (order by date range between interval 6 day preceding and current row)
from t;