I am looking to summarize date and need to find a way of doing a 3 day trailing sum, sum of the current date and the 2 previous days. I am using MariaDB, a MYSQL fork.

Here is a subset of the data;

```
select Date, Total from keywordSum limit 5;
+------------+--------+
| Date       | Total  |
+------------+--------+
| 2010-11-11 | 316815 |
| 2010-11-12 | 735305 |
| 2010-11-13 | 705116 |
| 2010-11-14 | 725020 |
| 2010-11-15 | 745378 |
+------------+--------+

```

I would like to end up with a result similar to this:

```
+------------+--------+-----------+
| Date       | Total  | 3DayTotal |
+------------+--------+-----------+
| 2010-11-11 | 316815 |    316815 |
| 2010-11-12 | 735305 |   1052120 |
| 2010-11-13 | 705116 |   1757236 |
| 2010-11-14 | 725020 |   2167441 |
| 2010-11-15 | 745378 |   2177514 |
+------------+--------+-----------+

```

It could even print NaN or leave it blank if the previous days don't exist. Any thoughts or suggestions would be greatly appreciated.