Ok, i have a table with a `date` column and a `integer` column, and i want to retrieve all the rows
grouped by date's day within a certain date range; since there are not rows for every day, is it possible to make mysql return rows for those days with a default value?

example
-------

source table:

```
date         value
2020-01-01   1
2020-01-01   2
2020-01-03   2
2020-01-07   3
2020-01-08   4
2020-01-08   1

```

Standard behaviour after `group`ing by date and `sum`ming values:

```
2020-01-01   3
2020-01-03   2
2020-01-07   3
2020-01-08   5

```

Desired behaviour/result with empty rows:

```
2020-01-01   3
2020-01-02   0
2020-01-03   2
2020-01-04   0
2020-01-05   0
2020-01-06   0
2020-01-07   3
2020-01-08   5

```