Hi,
I have a question about using Group By.
On a table like this:
Type (varchar) | Active (boolean)
--------------------------------------------------------
Type One | False
Type Two | True
Type One | True
Type Fifty | Flase
Type Two | True
Having this table I want a report grouping Types and giving me more
statistics such as:
Type | Active Count | Inactive Count | Active
Percent
How do i do that?
I can think of :
select Type from table_name group by Type
This should been quite easy - the trick is aggregate functions omit NULL
values (maybe there is some other / better way):
SELECT type,
COUNT(CASE WHEN active THEN 1 ELSE NULL END) AS active_count,
COUNT(CASE WHEN active THEN NULL ELSE 1 END) AS
inactive_count,
COUNT(CASE WHEN active THEN 1 ELSE NULL END) / COUNT(*)
AS active_pct
FROM table_name;
but have not tested it ;(
Tomas
