feat: update structure

cs2102/labs/midterms/2110.sql

@@ -0,0 +1,38 @@
+-- Q1
+SELECT c.name
+FROM countries c
+WHERE c.population > 100000000
+AND c.continent = 'Africa';
+
+SELECT c.continent, COUNT(*)
+FROM countries c
+WHERE NOT EXISTS (
+    SELECT 1
+    FROM airports a
+    WHERE c.iso2 = a.country_iso2
+    )
+GROUP BY c.continent;
+
+SELECT c.name, COUNT(*)
+FROM borders b, countries c
+WHERE c.iso2 = b.country1_iso2
+GROUP BY c.iso2
+ORDER BY COUNT(*) DESC
+LIMIT 10;
+
+SELECT b.country1_iso2, b.country2_iso2
+FROM borders b, countries c1, countries c2
+WHERE b.country1_iso2 = c1.iso2
+AND b.country2_iso2 = c2.iso2
+AND c1.continent = 'Asia' AND c2.continent = 'Europe';
+
+SELECT c.name
+FROM countries c
+WHERE NOT EXISTS(
+    SELECT *
+    FROM routes r, airports a, countries c1
+    WHERE r.airline_code = 'SQ'
+    AND c1.continent = 'Asia'
+    AND r.to_code = a.code
+    AND c1.iso2 = a.country_iso2
+) AND c.continent = 'Asia';