SQL Server: Common mistake while Calculating Quarter Sales

When it comes to calculating quarter sales, I have always seen developers grouping only by quarter. For eg: Assuming we have a table called SalesTable with columns – SalesDate and Qty. To calculate the quantity sold per quarter, developers usually write the query as:

SQL Quarter Grouping

Now if the data is only for a year, the query would work. However this is seldom the case. In most of the reports I have seen,  end users want to see the quarters for 'each' year. So to do it correctly, you have to add the year too in the GroupBy clause, as shown below:

SQL Quarter Grouping

Now the query will differentiate each quarter by its year and produce correct results. It's a simple tip, but very easy to forget!

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

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