SQL Exercises: All winners in Physics for 1970 and Economics for 1971
19. Combine Winners (Physics 1970 & Economics 1971)
From the following table, write a SQL query that combines the winners in Physics, 1970 and in Economics, 1971. 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 ..... 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 'Physics' and the 'year' is 1970.
WHERE (subject = 'Physics' AND year = 1970)
-- 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 'Economics' and the 'year' is 1971.
(SELECT * FROM nobel_win WHERE (subject = 'Economics' AND year = 1971));
Output of the Query:
year subject winner country category 1970 Physics Hannes Alfven Sweden Scientist 1970 Physics Louis Neel France Scientist 1971 Economics Simon Kuznets Russia Economist
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 'Physics' and the year is 1970. The second query selects all columns from the table where the subject is 'Economics' and the year is 1971. 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 in 1970 for physics and 1971 for economics.
Relational Algebra Expression:
Relational Algebra Tree:
Go to:
PREV : Winners with First Name Louis.
NEXT : 1970 Winners Excluding Physiology & Economics.
Practice Online
For more Practice: Solve these Related Problems:
- Write a SQL query to combine winners in Chemistry (1965) and Literature (1970).
- Write a SQL query to merge winners in Physiology (1970) and Peace (1971).
- Write a SQL query to display winners in Physics (1980) and Economics (1985).
- Write a SQL query to combine winners in Literature (1990) and Peace (1995).
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