For displaying the percent to total in SQL, we want to leverage the ideas we used for rank/running total plus subquery.

Different from what we saw in the SQL Subquery section, here we want to use the subquery as part of the SELECT.

Name        Sales

Himanshu     10

Manish       15    

Prateek      20

Mayank       40

Suresh       50

Mohan        20

Then we will perform the query to get percent total

SELECT a1.Name, a1.Sales, a1.Sales/(SELECT SUM(Sales) FROM Total_Sales) Pct_To_Total
FROM Total_Sales a1, Total_Sales a2
WHERE a1.Sales <= a2.sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name, a1.Sales
ORDER BY a1.Sales DESC, a1.Name DESC;

Name	       Sales	     Pct_To_Total

Himanshu	50	        0.3226

Manish		40              0.2581

Prateek		20              0.1290

Mayank		20              0.1290

Suresh	        15	        0.0968

Mohan	        10	        0.0645