Question

I have two tables I need to create an average sum from…

Caravan Category M:1 Caravan (caravan has one category, category has many caravans)

Caravan (Caravan_no, rental_amount, annual_rent….

Caravan Category (Caravan_type_id, car_type, pets ….

Caravan Category type has such entities as; American Classic, Conventional, Twin GRP…

I want to create an SQL query that will return a list that show the average cost for a particular caravan type e.g ‘200 ‘Average cost for’ American Classic and so on..

NOTE: car_type has a ‘check in’ constraint of 8 different caravan types so this will stop the user choosing a caravan type that is not listed and messing this up.

USING ORACLE APEX 4.0

Any helpers??

Answer 1

Something like the below ought to do the trick (some field names may need to be changed to match your schema):

SELECT CC.description, AVG(C.rental_amount)
FROM CaravanCategory CC
INNER JOIN Caravan C
ON C.Caravan_Type_id = CC.Caravan_Type_id
GROUP BY CC.description