Question

SQL – Microsoft Access

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Display the percent of charter trips that have co-pilots and use COUNT

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CHAR PLOT CHAR COPILOT AC NUMBER CHAR DESTINATION CHAR DISTANCE CHAR HOURS FLOWN CHAR HOURS AT CHAR FUEL GALLONS CHAR OL QTS CUS COE CHARTRIP CHAR DATE - 109 4278Y 49 35 105 2778V 4.5

Answer 1

SELECT ((COUNT(CHAR_COPILOT)/COUNT(CHAR_TRIP))*100 AS PERCENT_TRIP FROM <TABLE_NAME>

explanation:

COUNT(variable) -- counts the no of rows which dont have NULL as their value.

COUNT(*) -- returns the all rows which have null and not nulla.

COUNT(CHAR_COPILOT) gives only no of copilots which have the values (doesnt consider nulls)

COUNT(CHAR_TRIP) - gives only no of trips which have the values (doesnt consider nulls)

(COUNT(CHAR_COPILOT)/COUNT(CHAR_TRIP)) -- divides the no of copilot rows with no of total trips

then multiply with 100 to get percentage.

note: if u have any doubt, let me know.