course content

Course Content

Intermediate SQL

Challenge: Average Ride Time for Each Subway LineChallenge: Average Ride Time for Each Subway Line

Note

AVG(column) function returns the average value of some column.

The ORDER BY clause can sort the data in descending order. To do this, we need to specify the keyword DESC.

Task

You have to count the average ride time (create a new column, named average_time using time_to_next_station and AVG() function) of the driving of each subway line (line_name column). Order the result by the average_time column in descending order.

Here's a short example of the relation table:

relation_idline_namestation_nametime_to_next_station
1GreenAngrignon10
2GreenMonk16
3GreenVerdun9
............
21YellowLongueuil10

Everything was clear?

Section 1. Chapter 4
toggle bottom row