Course Content
Intermediate SQL
2. Nested Subqueries
4. Left, Right, and Inner Joins
Intermediate SQL
Challenge: Total Ride Time for Each Subway Line
Note
SUM(column)
is the function returns the sum of the values in a specific colum.
Task
Calculate the total ride time for each subway line by creating a new column called total_time
using the time_to_next_station
values and the SUM()
function. Following that, arrange the outcome in ascending order using the total_time
column.
Here's a short example of the relation
table:
relation_id | line_name | station_name | time_to_next_station |
1 | Green | Angrignon | 10 |
2 | Green | Monk | 16 |
3 | Green | Verdun | 9 |
... | ... | ... | ... |
21 | Yellow | Longueuil | 10 |
Everything was clear?
Section 1. Chapter 3