Average in order by clause

Question

I have this query:

SELECT 
   Field1
   AVG(Field2) as Field2, 
   AVG(Field3) as Field3, 
   AVG(Field4) as Field4 
FROM Table1
GROUP BY Field1
ORDER BY Field2 DESC, Field3 DESC, Field4 DESC

How to (if is possible) order with average of the three fields? I want to make a single order after getting an average of three fields. For example:

...
ORDER BY (Field2 + Field3 + Field4) / 3

Answer 1

To sort on the average of Field1 + Field2 + Field3 you can either add a new field and sort on that.

select Field1,   
       avg(Field2) as AField2, 
       avg(Field3) as AField3, 
       avg(Field4) as AField4,
       avg(Field2+Field3+Field4) as Sort
from Table1
group by Field1
order by Sort desc

Or you can put your query in a sub-query and sort on the sum of the fields in the outer query.

select T.Field1,
       T.AField2,
       T.AField3,
       T.AField4
from (select Field1,   
             avg(Field2) as AField2, 
             avg(Field3) as AField3, 
             avg(Field4) as AField4
      from Table1
      group by Field1) as T
order by T.AField2 + T.AField3 + T.AField4 desc