Exercise

Filtering using scalar subqueries

Subqueries are incredibly powerful for performing complex filters and transformations. You can filter data based on single, scalar values using a subquery in ways you cannot by using WHERE statements or joins. Subqueries can also be used for more advanced manipulation of your data set. You will likely encounter subqueries in any real-world setting that uses relational databases.

In this exercise, you will generate a list of matches where the total goals scored (for both teams in total) is more than 3 times the average for games in the matches_2013_2014 table, which includes all games played in the 2013/2014 season.

Instructions 1/2

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  • Calculate triple the average home + away goals scored across all matches. This will become your subquery in the next step. Note that this column does not have an alias, so it will be called ?column? in your results.