w3resource

SQL Exercise: Referee who assisted in the opening match

SQL soccer Database: Joins Exercise-10 with Solution

10. From the following tables, write a SQL query to find the referee who assisted the referee in the opening 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 match_no=1;

Sample Output:

 ass_ref_name | country_name
--------------+--------------
 Gyorgy Ring  | Hungary
 Vencel Toth  | Hungary
(2 rows)

Code Explanation:

The said query in SQL that retrieves information about the assistant referee and country for the match with match_no equal to 1 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 only those rows for the match with match_no equal to 1 will be selected.

Relational Algebra Expression:

Relational Algebra Expression: Find the name and country of the referee who assisted the referee in the opening match.

Relational Algebra Tree:

Relational Algebra Tree: Find the name and country of the referee who assisted the referee in the opening match.

Practice Online


Sample Database: soccer

soccer database relationship structure

Query Visualization:

Duration:

Query visualization of Find the name and country of the referee who assisted the referee in the opening match - Duration

Rows:

Query visualization of Find the name and country of the referee who assisted the referee in the opening match - Rows

Cost:

Query visualization of Find the name and country of the referee who assisted the referee in the opening match - Cost

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous SQL Exercise: Name and country of referee who managed the final game.
Next SQL Exercise: Referee who assisted in the final match.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Follow us on Facebook and Twitter for latest update.

SQL: Tips of the Day

What is the best way to paginate results in SQL Server?

SELECT  *
FROM    ( SELECT    ROW_NUMBER() OVER ( ORDER BY OrderDate ) AS RowNum, *
          FROM      Orders
          WHERE     OrderDate >= '1980-01-01'
        ) AS RowConstrainedResult
WHERE   RowNum >= 1
    AND RowNum < 20
ORDER BY RowNum

Database: SQL Server

Ref: https://bit.ly/3MGrNlk

 





We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook