01173-immediate-food-delivery-i.sql

-- simple condition in aggregate function- count immediate, divide by total rows in the table

select round(sum(order_date = customer_pref_delivery_date) / count(*) * 100, 2) as immediate_percentage
from Delivery
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-- same as above but using case

select round(sum( case when order_date = customer_pref_delivery_date then 1 else 0 end) / count(*) * 100, 2) as immediate_percentage
from Delivery


-- doordash- 2