How can I compute the average of a nested SQL statement? - mysql

Question

I have this crazy nested sql statement and it returns something like this:
However, what I want is to use this data in the image to return 2 columns. col_1:SUM(avgWithCriteria)/43 and col_2:SUM(avgWithoutCriteria)/43. How can I do this by adding onto my query below?
SELECT
( ( avgWithCriteria - totalAverage ) / ( ( avgWithCriteria + totalAverage ) / 2 ) ) * 100 as percentDifference,
a.*
FROM
(SELECT
AVG( CASE WHEN 'f' not in ( has_free_parking ) THEN price ELSE null END) as avgWithCriteria,
AVG( CASE WHEN 'f' in ( has_free_parking ) THEN price ELSE null END) as avgWithoutCriteria,
AVG( price ) as totalAverage,
neighbourhood_cleansed
FROM listings
WHERE city_name="berlin"
AND price <= 1000000
AND price >= -1
AND reviews_per_month <= 1000000
AND reviews_per_month >= -1
AND est_monthly_income <= 1000000
AND est_monthly_income >= -1
GROUP BY neighbourhood_cleansed ) a;

Answer 1

Try this:-
SELECT percentDifference,avgWithCriteria,avgWithoutCriteria,totalAverage,neighbourhood_cleansed,
(col1_1/43) as col1,(col2_2/43) as col2
from
(
SELECT a.*,SUM(avgWithCriteria) as col1_1,SUM(avgWithoutCriteria) as col2_2
FROM
(
SELECT
( ( avgWithCriteria - totalAverage ) / ( ( avgWithCriteria + totalAverage ) / 2 ) ) * 100 as percentDifference,
a.*
FROM
(SELECT
AVG( CASE WHEN 'f' not in ( has_free_parking ) THEN price ELSE null END) as avgWithCriteria,
AVG( CASE WHEN 'f' in ( has_free_parking ) THEN price ELSE null END) as avgWithoutCriteria,
AVG( price ) as totalAverage,
neighbourhood_cleansed
FROM listings
WHERE city_name="berlin"
AND price <= 1000000
AND price >= -1
AND reviews_per_month <= 1000000
AND reviews_per_month >= -1
AND est_monthly_income <= 1000000
AND est_monthly_income >= -1
GROUP BY neighbourhood_cleansed ) a
) a
GROUP BY percentDifference,avgWithCriteria,avgWithoutCriteria,totalAverage,neighbourhood_cleansed
) a;

Answer 2

SELECT
( ( avgWithCriteria - totalAverage ) / ( ( avgWithCriteria + totalAverage ) / 2 ) ) * 100 as percentDifference,
SUM(avgWithCriteria)/43 AS col_1,
SUM(avgWithoutCriteria)/43 AS col_2,
a.*
FROM
(SELECT
AVG( CASE WHEN 'f' not in ( has_free_parking ) THEN price ELSE null END) as avgWithCriteria,
AVG( CASE WHEN 'f' in ( has_free_parking ) THEN price ELSE null END) as avgWithoutCriteria,
AVG( price ) as totalAverage,
neighbourhood_cleansed
FROM listings
WHERE city_name="berlin"
AND price <= 1000000
AND price >= -1
AND reviews_per_month <= 1000000
AND reviews_per_month >= -1
AND est_monthly_income <= 1000000
AND est_monthly_income >= -1
GROUP BY neighbourhood_cleansed ) a;