SQL Exercise: Find the number of venues for EURO cup 2016

Last update on December 20 2024 12:02:40 (UTC/GMT +8 hours)

1. From the following table, write a SQL query to count the number of venues for EURO cup 2016. Return number of venues.

 venue_id |       venue_name        | city_id | aud_capacity
----------+-------------------------+---------+--------------
    20001 | Stade de Bordeaux       |   10003 |        42115
    20002 | Stade Bollaert-Delelis  |   10004 |        38223
    20003 | Stade Pierre Mauroy     |   10005 |        49822
    20004 | Stade de Lyon           |   10006 |        58585
    20005 | Stade VElodrome         |   10007 |        64354
    20006 | Stade de Nice           |   10008 |        35624
    20007 | Parc des Princes        |   10001 |        47294
    20008 | Stade de France         |   10002 |        80100
    20009 | Stade Geoffroy Guichard |   10009 |        42000
    20010 | Stadium de Toulouse     |   10010 |        33150

Sample Solution:

-- This SQL query calculates the total number of rows in the 'soccer_venue' table.

SELECT COUNT(*) 
-- COUNT(*) is an aggregate function that counts the number of rows in a result set.
FROM soccer_venue;
-- 'soccer_venue' is the name of the table from which the count is being calculated.

Sample Output:

 count
-------
    10
(1 row)

Code Explanation:

The said query in SQL that counts the total number of rows in the soccer_venue table. The COUNT(*) function is an aggregate function that counts the number of rows returned by a query. The result of the query will be a single value, which represents the total number of rows in the soccer_venue table.

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

Sample Database: soccer

Query Visualization:

Duration:

Rows:

Cost:

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