38 lines
847 B
SQL
38 lines
847 B
SQL
-- Q1
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SELECT c.name
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FROM countries c
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WHERE c.population > 100000000
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AND c.continent = 'Africa';
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SELECT c.continent, COUNT(*)
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FROM countries c
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WHERE NOT EXISTS (
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SELECT 1
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FROM airports a
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WHERE c.iso2 = a.country_iso2
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)
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GROUP BY c.continent;
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SELECT c.name, COUNT(*)
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FROM borders b, countries c
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WHERE c.iso2 = b.country1_iso2
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GROUP BY c.iso2
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ORDER BY COUNT(*) DESC
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LIMIT 10;
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SELECT b.country1_iso2, b.country2_iso2
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FROM borders b, countries c1, countries c2
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WHERE b.country1_iso2 = c1.iso2
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AND b.country2_iso2 = c2.iso2
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AND c1.continent = 'Asia' AND c2.continent = 'Europe';
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SELECT c.name
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FROM countries c
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WHERE NOT EXISTS(
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SELECT *
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FROM routes r, airports a, countries c1
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WHERE r.airline_code = 'SQ'
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AND c1.continent = 'Asia'
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AND r.to_code = a.code
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AND c1.iso2 = a.country_iso2
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) AND c.continent = 'Asia'; |