Why do i get a an error that a column must appear in an aggregate or group by clause when it is already there?

I wrote this SQL query:

SELECT       P.city, D.month_name,        SUM(F.number_resolved) OVER W AS "number of positive cases"  FROM       public.phu_location_dimension AS P  JOIN       public.fact_table AS F ON P.phu_surrogate_key = F.phu_location_surrogate  JOIN       public.date_dimension AS D ON D.date_surrogate =  F.reported_date_surrogate  GROUP BY       P.city, D.month_name  WINDOW W AS            (PARTITION BY P.city ORDER BY D.date_actual             RANGE BETWEEN INTERVAL '1'  MONTH PRECEDING              AND INTERVAL '1' MONTH FOLLOWING)  ORDER BY       P.city  

However, I get the error

ERROR: column "f.number_resolved" must appear in the GROUP BY clause or be used in an aggregate function
LINE 1: SELECT P.city, D.month_name, SUM(F.number_resolved) over W...

I am using the number resolved in an aggregate function, so why is there an error. Can someone please help with this ?

https://stackoverflow.com/questions/66739546/why-do-i-get-a-an-error-that-a-column-must-appear-in-an-aggregate-or-group-by-cl March 22, 2021 at 10:20AM