SQL Exercise: Name and country of referee who managed the first game

SQL soccer Database: Joins Exercise-8 with Solution

8. From the following tables, write a SQL query to find the referee who managed the opening match. Return referee name, country name.

Sample table: soccer_country

Sample table: match_mast

Sample table: referee_mast

Sample Solution:

SQL Code:

SELECT b.referee_name, c.country_name 
FROM match_mast a
NATURAL JOIN referee_mast b 
NATURAL JOIN soccer_country c
WHERE match_no=1;

Sample Output:

 referee_name  | country_name
---------------+--------------
 Viktor Kassai | Hungary
(1 row)

Code Explanation:

The provided query in SQL that retrieves information about the referee and country for the match with match_no equal to 1 from the tables match_mast, referee_mast, and soccer_country.
The NATURAL JOIN keyword is used to join the tables match_mast, referee_mast, and soccer_country based on columns with the same name in each table.
The condition filters only those rows for the match with match_no equal to 1.

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

Sample Database: soccer

Query Visualization:

Duration:

Rows:

Cost:

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