Average result of last 10 rows

Question

I'm trying to find the average figure for the last 10 rows in a database table:

select avg(Reading)
from Readings
Order By Rowid
desc limit 10;

This pulls the average of all entries in the table, not the last 10. I've tried all sorts of variations but can't get it to work.

select the last 10 rows and then run the average on those separately. — Versatile, Sep 09 '16 at 20:57
Select the last 10 rows as a resultset (subquery in the from clause) then apply the required grouping on that set of rows. — Ryan Vincent, Sep 09 '16 at 20:58

score 2 · Answer 1 · edited Sep 10 '16 at 05:31

2

Thanks for the super quick replies, I tried again and managed to type in the correct syntax this time in the From clause.

Here is the correct answer:

select avg(Reading)
from(select Reading
     from Readings
     Order By Rowid desc
     limit 10);

edited Sep 10 '16 at 05:31

CL.

answered Sep 09 '16 at 21:10

PeteBradshaw

1 Answers1