I want to calculate the median of revenue but show the following error and I don’t understand why:

Column ‘finance.revenue’ is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

This is my code:

with footwear as (
    select
        description,
        revenue
    from
        info i
        inner join finance f on i.product_id = f.product_id
    where
        (description like '%shoe%'
        or description like '%trainer%'
        or description like '%foot%')
        and description is not null
)
select 
   count(*) as num_of_products,
   percentile_disc(0.5) within group (order by revenue) over() as median_clothing_revenue
from
   info i
   inner join finance f on i.product_id = f.product_id
where
   i.description not in (select description from footwear);