SQL Exercise: Number of matches got a result by penalty shootout

Last update on January 13 2026 12:20:14 (UTC/GMT +8 hours)

9. From the following table, write a SQL query to find the number of matches that resulted in a penalty shootout.

Sample table: penalty_shootout

 kick_id | match_no | team_id | player_id | score_goal | kick_no
---------+----------+---------+-----------+------------+---------
       1 |       37 |    1221 |    160467 | Y          |       1
       2 |       37 |    1213 |    160297 | Y          |       2
       3 |       37 |    1221 |    160477 | N          |       3
       4 |       37 |    1213 |    160298 | Y          |       4
       5 |       37 |    1221 |    160476 | Y          |       5
       6 |       37 |    1213 |    160281 | Y          |       6
       7 |       37 |    1221 |    160470 | Y          |       7
       8 |       37 |    1213 |    160287 | Y          |       8
       9 |       37 |    1221 |    160469 | Y          |       9
.......
      37 |       47 |    1208 |    160166 | Y          |      18

View the table

Sample Solution:

-- This SQL query calculates the count of distinct 'match_no' values in the 'penalty_shootout' table.

SELECT COUNT(DISTINCT match_no) 
-- COUNT(DISTINCT match_no) counts the number of unique 'match_no' values in the result set.
FROM penalty_shootout;
-- 'penalty_shootout' is the name of the table from which the distinct 'match_no' count is being calculated.

Sample Output:

 count
-------
     3
(1 row)

Code Explanation:

The said query in SQL that selects the count of distinct values in the match_no column of the penalty_shootout table.
The result of the query will be a single value. This query will count the number of unique matches that have penalty shootouts recorded in the penalty_shootout table.

Relational Algebra Expression: