Add a window function
Fantastic! You now have a result set that retrieves the match date, home team, away team, and the goals scored by each team. You have one final component of the question left -- how badly did Manchester United lose in each match?
In order to determine this, let's add a window function to the main query that ranks matches by the absolute value of the difference between home_goal
and away_goal
. This allows us to directly compare the difference in scores without having to consider whether Manchester United played as the home or away team!
The equation is complete for you -- all you need to do is properly complete the window function!
This exercise is part of the course
Data Manipulation in SQL
Exercise instructions
- Set up the CTEs so that the home and away teams each have a name, ID, and score associated with them.
- Select the date, home team name, away team name, home goal, and away goals scored in the main query.
- Rank the matches and order by the difference in scores in descending order.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
-- Set up the home team CTE
___ ___ ___ (
SELECT m.id, t.team_long_name,
CASE WHEN m.home_goal > m.away_goal THEN 'MU Win'
WHEN m.home_goal < m.away_goal THEN 'MU Loss'
ELSE 'Tie' END AS outcome
FROM match AS m
LEFT JOIN team AS t ON m.hometeam_id = t.team_api_id),
-- Set up the away team CTE
___ ___ (
SELECT m.id, t.team_long_name,
CASE WHEN m.home_goal > m.away_goal THEN 'MU Loss'
WHEN m.home_goal < m.away_goal THEN 'MU Win'
ELSE 'Tie' END AS outcome
FROM match AS m
LEFT JOIN team AS t ON m.awayteam_id = t.team_api_id)
-- Select columns and and rank the matches by goal difference
SELECT DISTINCT
___,
___.___ AS home_team,
___.___ AS away_team,
m.home_goal, m.away_goal,
___() ___(___ ___ ABS(home_goal - away_goal) ___) as match_rank
-- Join the CTEs onto the match table
FROM match AS m
___ JOIN ___ ON m.id = ___
___ JOIN ___ ON m.id = ___
WHERE m.season = '2014/2015'
AND ((home.team_long_name = 'Manchester United' AND home.outcome = 'MU Loss')
OR (away.team_long_name = 'Manchester United' AND away.outcome = 'MU Loss'));