Combine Output of Queries in Pivot Table with PostgreSQL - sql

Question

Suppose I have a table called orders that looks like this:
id
order date
Orders_Wanted
Orders_Given
1
2020-11-29 19:12:44.417
2
6
1
2020-11-29 20:12:44.417
2
6
1
2020-11-30 23:37:28.692
8
2
1
2020-11-30 23:37:28.692
2
6
How do I write a query that shows the count of orders_wanted - orders_given by hour broken down into two columns, one that counts positive results and one that counts negative results (a note that orders_wanted and orders_given are times, so that's why I am calculating orders_wanted - orders_given). I would also like to add a final column that calculates the percentage of total orders per hour that are positive (count_orders_positive/ (count_orders_negative + Count_orders_positive)).
The output of the query would look something like this:
week
day
hour
count_orders_positive
count_orders_negative
Percentage_orders_positive
48
7
19
0
1
100%
48
7
20
0
1
100%
49
1
23
1
1
50%
So far I am able to get the bottom two results using these queries, but I don't know how to combine them.
SELECT
extract (week from (order_date at time zone 'MST' at time zone 'UTC') ) as "week",
extract (isodow from (order_date at time zone 'MST' at time zone 'UTC') ) as "day",
extract (hour from (order_date at time zone 'MST' at time zone 'UTC') ) as "hour",
Count (extract (hour from (order_date at time zone 'MST' at time zone 'UTC') )) as
"count_orders_positive"
from orders
WHERE orders_wanted - orders_given >= 0
group by week, day, hour
order by week, day, hour;
week
day
hour
count_orders_positive
49
1
23
1
SELECT
extract (week from (order_date at time zone 'MST' at time zone 'UTC') ) as "week",
extract (isodow from (order_date at time zone 'MST' at time zone 'UTC') ) as "day",
extract (hour from (order_date at time zone 'MST' at time zone 'UTC') ) as "hour",
Count (extract (hour from (order_date at time zone 'MST' at time zone 'UTC') )) as
"count_orders_negative"
from orders
WHERE orders_wanted - orders_given < 0
group by week, day, hour
order by week, day, hour;
week
day
hour
count_orders_negative
48
7
19
1
48
7
20
1
49
1
23
1

Answer 1

You can do conditional aggregation. avg() comes handy to compute the percentage:
select
extract (week from (order_date at time zone 'MST' at time zone 'UTC') ) as "week",
extract (isodow from (order_date at time zone 'MST' at time zone 'UTC') ) as "day",
extract (hour from (order_date at time zone 'MST' at time zone 'UTC') ) as "hour",
count(*) filter (where orders_wanted - orders_given >= 0) as count_orders_positive,
count(*) filter (where orders_wanted - orders_given < 0) as count_orders_negative,
100 * avg((orders_wanted - orders_given >= 0)::int) as percent_orders_positive
from orders
group by week, day, hour
order by week, day, hour;