Calculate Percentage in SQL Server

The following T-SQL script shows a simple example to calculate Percentage in SQL Server. We will be using a table which contains Grades and calculate the percentage weight of each grade, for the entire classroom

SAMPLE DATA

CREATE TABLE #ClassRoom(ID INT IDENTITY(1,1), Grade char(2) NULL);
GO
-- Code by SqlServerCurry.com
INSERT INTO #ClassRoom Values ('A');
INSERT INTO #ClassRoom Values ('B');
INSERT INTO #ClassRoom Values ('B+');
INSERT INTO #ClassRoom Values ('B');
INSERT INTO #ClassRoom Values ('A');
INSERT INTO #ClassRoom Values ('A+');
INSERT INTO #ClassRoom Values ('B');
INSERT INTO #ClassRoom Values ('B');
INSERT INTO #ClassRoom Values ('A+');
INSERT INTO #ClassRoom Values ('C');

QUERY

SELECT Grade,
CONVERT(varchar, 100 * count(*) / tot,1) + '%' as 'Percent'
FROM #ClassRoom,
(SELECT COUNT(*) as tot FROM #ClassRoom) x
GROUP BY Grade, tot

The CONVERT function formats the percentage figure so that you get the result in a percentage format.

OUTPUT

Calculate Percentage SQL


About The Author

Suprotim Agarwal, MCSD, MCAD, MCDBA, MCSE, is the founder of DotNetCurry, DNC Magazine for Developers, SQLServerCurry and DevCurry. He has also authored a couple of books 51 Recipes using jQuery with ASP.NET Controls and a new one recently at The Absolutely Awesome jQuery CookBook.

Suprotim has received the prestigous Microsoft MVP award for nine times in a row now. In a professional capacity, he is the CEO of A2Z Knowledge Visuals Pvt Ltd, a digital group that represents premium web sites and digital publications comprising of Professional web, windows, mobile and cloud developers, technical managers, and architects.

Get in touch with him on Twitter @suprotimagarwal, LinkedIn or befriend him on Facebook

4 comments:

Anonymous said...

Good one...Thanks.

Anonymous said...

Good one.

גרי רשף said...

My contribution:

Select Grade,
Cast((100*COUNT(*))/Sum(COUNT(*)) Over() As Varchar)+'%' 'Percent'
From #ClassRoom
Group By Grade

Suprotim Agarwal said...

Absolutely. Using OVER() is a nice alternative!