SQL-报表中的多个分组

Question

I have a table structured similarly to this:

ID
Incident_Name
Category
Source

I need a report to show all incidents grouped by category but then the amount of incidents in that category that have a certain source value.

Category   | Amount | Percentage of Total | Source_1 | Source_2 | Source 3
----------------------------------------------------------------------------
Category 1 | 5      | 25%                 | 1        | 3        | 2
Category 2 | 15     | 75%                 | 10       | 2        | 3

I'm using MySQL - how would I go about doing this.

Grouping and getting the amount/percentage is fine but not sure how I'd go about doing the rest.

SELECT Category, COUNT(*) AS Amount, (COUNT(*) / (SELECT COUNT(*) FROM MyTable)) * 100 AS 'Percentage of Total', 
FROM MyTable
GROUP BY Category;

Any advice

Answer 1

I think this is what you are trying to do.

SELECT Category, 
COUNT(*) AS Amount,
(COUNT(*) / (SELECT COUNT(*) FROM MyTable)) * 100 AS 'Percentage of Total', 
SUM(source=someval1) as Source_1, --this may need a change
SUM(source=someval2) as Source_2, --this may need a change
SUM(source=someval3) as Source_3  --this may need a change
FROM MyTable
GROUP BY Category;