On how many days with the max temperature over 90 did the sale of item no.5 in store no.3 exceed 100?
max temperature over 90 refers to tmax > 90; item no. 5 refers to item_nbr = 5; store no.3 refers to store_nbr = 3; sale exceed 100 refers to units > 100; number of days refers to count (date)
SELECT SUM(CASE WHEN units > 100 THEN 1 ELSE 0 END) AS count FROM sales_in_weather AS T1 INNER JOIN relation AS T2 ON T1.store_nbr = T2.store_nbr INNER JOIN weather AS T3 ON T2.station_nbr = T3.station_nbr WHERE T2.store_nbr = 3 AND SUBSTR(T1.`date`, 1, 4) = '2012' AND T1.item_nbr = 5 AND tmax > 90