From 8dcde72666f6baf9bf9d62b758e78bbd552d9a68 Mon Sep 17 00:00:00 2001
From: AdityaTharunJ <adityatarunjandhyala6996@gmail.com>
Date: Wed, 3 Jun 2026 12:59:17 +0530
Subject: [PATCH] Enhance SQL exercises with population calculations

Add queries to calculate continent population and percentage of world population, as well as count towns per region.
---
 SQL Deep Dive/Window Functions/exercises.sql | 35 +++++++++++++++-----
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/SQL Deep Dive/Window Functions/exercises.sql b/SQL Deep Dive/Window Functions/exercises.sql
index 6b3a32c..c92aec9 100644
--- a/SQL Deep Dive/Window Functions/exercises.sql	
+++ b/SQL Deep Dive/Window Functions/exercises.sql	
@@ -3,10 +3,10 @@
 *  Database: World
 *  Table: Country
 */
-
-SELECT *
-FROM country;
-
+SELECT DISTINCT continent, SUM(population) 
+OVER w1 AS "Continent Population" 
+FROM country
+WINDOW w1 AS (PARTITION BY continent);
 /*
 *  To the previous query add on the ability to calculate the percentage of the world population
 *  What that means is that you will divide the population of that continent by the total population and multiply by 100 to get a percentage.
@@ -16,10 +16,18 @@ FROM country;
 *  Database: World
 *  Table: Country
 */
-
-SELECT *
-FROM country;
-
+SELECT
+  DISTINCT continent,
+  SUM(population) OVER w1 as"continent population",
+  CONCAT( 
+      ROUND( 
+          ( 
+            SUM(population::float4) OVER w1 / 
+            SUM(population::float4) OVER() 
+          ) * 100    
+      ),'%' ) as "% of population"
+FROM country 
+WINDOW w1 AS( PARTITION BY continent );
 
 /*
 *  Count the number of towns per region
@@ -28,5 +36,14 @@ FROM country;
 *  Table: Regions (Join + Window function)
 */
 
-SELECT *
+SELECT DISTINCT r.id,
+r."name",
+COUNT(t.id) OVER(
+  PARTITION BY r.id
+  ORDER BY r."name"
+  ) AS "No of towns"
+  FROM regions as r
+  JOIN departments as d ON r.code = d.region
+  JOIN towns as t ON d.code = t.department
+  ORDER BY r.id;
 FROM regions AS r;