SQL Exercise: Physiology prize before 71 with a Peace prize after 74

SQL Basic Select Statement: Exercise-21 with Solution.

From the following table, write a SQL query to combine the winners in 'Physiology' before 1971 and winners in 'Peace' on or after 1974. Return year, subject, winner, country, and category.

Sample table: nobel_win

YEAR SUBJECT                   WINNER                                        COUNTRY                CATEGORY
---- ------------------------- --------------------------------------------- ------------------------- ------------
1970 Physics                   Hannes Alfven                                 Sweden                 Scientist
1970 Physics                   Louis Neel                                    France                 Scientist
1970 Chemistry                 Luis Federico Leloir                          France                 Scientist
1970 Physiology                Ulf von Euler                                 Sweden                 Scientist
1970 Physiology                Bernard Katz                                  Germany                Scientist
1970 Literature                Aleksandr Solzhenitsyn                        Russia                 Linguist
1970 Economics                 Paul Samuelson                                USA                    Economist
1970 Physiology                Julius Axelrod                                USA                    Scientist
1971 Physics                   Dennis Gabor                                  Hungary                Scientist
1971 Chemistry                 Gerhard Herzberg                              Germany                Scientist
1971 Peace                     Willy Brandt                                  Germany                Chancellor
1971 Literature                Pablo Neruda                                  Chile                  Linguist
1971 Economics                 Simon Kuznets                                 Russia                 Economist
1978 Peace                     Anwar al-Sadat                                Egypt                  President
1978 Peace                     Menachem Begin                                Israel                 Prime Minister
1987 Chemistry                 Donald J. Cram                                USA                    Scientist
1987 Chemistry                 Jean-Marie Lehn                               France                 Scientist
1987 Physiology                Susumu Tonegawa                               Japan                  Scientist
1994 Economics                 Reinhard Selten                               Germany                Economist
1994 Peace                     Yitzhak Rabin                                 Israel                 Prime Minister
1987 Physics                   Johannes Georg Bednorz                        Germany                Scientist
1987 Literature                Joseph Brodsky                                Russia                 Linguist
1987 Economics                 Robert Solow                                  USA                    Economist
1994 Literature                Kenzaburo Oe                                  Japan                  Linguist

Sample Solution:

-- This query selects all columns from the 'nobel_win' table.
SELECT *
-- Specifies the table from which to retrieve the data (in this case, 'nobel_win').
FROM nobel_win
-- Combines the results of two SELECT statements using the UNION operator.
-- The first SELECT statement retrieves rows where the 'subject' is 'Physiology' and the 'year' is less than 1971.
WHERE (subject = 'Physiology' AND year < 1971)
-- The UNION operator combines the results of the first SELECT statement with the results of the second SELECT statement.
UNION
-- The second SELECT statement retrieves rows where the 'subject' is 'Peace' and the 'year' is greater than or equal to 1974.
(SELECT * FROM nobel_win WHERE (subject = 'Peace' AND year >= 1974));

Output of the Query:

year	subject		winner		country	category
1970	Physiology	Bernard Katz	Germany	Scientist
1970	Physiology	Julius Axelrod	USA	Scientist
1970	Physiology	Ulf von Euler	Sweden	Scientist
1978	Peace		Anwar al-Sadat	Egypt	President
1978	Peace		Menachem Begin	Israel	Prime Minister
1994	Peace		Yitzhak Rabin	Israel	Prime Minister

Code Explanation:

The said SQL query retrieves all columns from the 'nobel_win' table and combines them with the results from another query. The first query selects all columns from the table where the subject is 'Physiology' and the year is less than 1971. The second query selects all columns from the table where the subject is 'Peace' and the year is greater than or equal to 1974. The UNION operator combines the results of both queries, returning all rows from the first query and the second query that are unique. The output will be a list of all unique nobel prize awarded before 1971 for physiology and after 1974 for peace

Relational Algebra Expression:

Relational Algebra Tree:

Practice Online

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Previous Python Exercise: The 1970 Nobel prize winners except for given subjects.
Next Python Exercise: Details of the prize won by Johannes Georg Bednorz.