I have a database that can be simplified as below:

+------------+---------+----------+
| Date | Clicks | Category |
+------------+---------+----------+
| 2019-10-24 | 100 | Widgets |
| 2019-10-24 | 200 | Widgets |
| 2019-10-24 | 300 | Gadgets |
| 2019-11-24 | 250 | Widgets |
| 2019-11-24 | 200 | Widgets |
| 2019-11-24 | 100 |    |
| 2019-11-24 | 200 | Gadgets |
| 2019-12-24 | 100 | Widgets |

What I want to do is group by both date and category (so I can plot the sum of clicks for the category over time). I've tried the below:

SELECT `Date`, `department`, SUM(`Clicks`) FROM `Category` WHERE `Category`<>'' GROUP BY `Category` , `Date`

Unfortunately, this doesn't work and I'm exhausting my rather lacking knowledge of SQL. From my example table above, I'm trying to get output like the below:

+------------+--------+----------+
| Date | Clicks | Category |
+------------+--------+----------+
| 2019-10-24 | 300 | Widgets |
| 2019-10-24 | 300 | Gadgets |
| 2019-11-24 | 450 | Widgets |
| 2019-12-24 | 200 | Gadgets |
| 2019-12-24 | 100 | Widgets |
+------------+--------+----------+

I.e. the sum of clicks for a given date grouped by category. If this is potentially a database design issue, I have the opportunity to change the database structure. Appreciate any help!