SQL Exercise: Referee who assisted in the final match

SQL soccer Database: Joins Exercise-11 with Solution

11. From the following tables, write a SQL query to find the referee who assisted the referee in the final match. Return associated referee name, country name.

Sample table: asst_referee_mast

Sample table: soccer_country

Sample table: match_details

Sample Solution:

SQL Code:

SELECT ass_ref_name, country_name 
FROM asst_referee_mast a
JOIN soccer_country b
ON a.country_id=b.country_id
JOIN match_details c
ON a.ass_ref_id=c.ass_ref
WHERE play_stage='F';

Sample Output:

 ass_ref_name | country_name
--------------+--------------
 Simon Beck   | England
 Jake Collin  | England
(2 rows)

Code Explanation:

The provided query in SQL retrieves information about the assistant referee and country for matches in the final stage from the tables asst_referee_mast, soccer_country, and match_details.
The JOIN keyword is used to join the tables based on columns specified in the ON clause. The asst_referee_mast and soccer_country are joined on the country_id column, while asst_referee_mast and match_details are joined on the ass_ref_id column.
The condition filters rows for matches in the final stage, where play_stage is equal to 'F', will be selected.

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

Sample Database: soccer

Query Visualization:

Duration:

Rows:

Cost:

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