Where and having in sql

Question

Hi, What is the difference between where and having clause? Thanks

satheesh d · Answer

Both WHERE clause and HAVING clause in the sql are used for filtering the data based on the certain conditions. WHERE clause doesn't work with the aggregate funcions like sum, min, Avg and others. For filtering data with the aggregate function, HAVING clause is used to filter the datas. WHERE clause is helps to filter the records before aggregate calculation and HAVING clause filter after the aggregate function. Having clause is slighyly slower than WHERE clause in performance and so it is better to use WHERE clause whenever needed. Select ProductName, SUM(ProductPrice) from [Products] GROUP BY ProductName HAVING ProductName IN ( 'Bag' , 'Pen' , 'Pencil' ) Select ProductName, SUM(ProductPrice) from [Products] WHERE ProductName IN ( 'Bag' , 'Pen' , 'Pencil' ) GROUP BY ProductName

Prabhu Raja · Answer

Hi Arjun, I think its better that you refer following blog from a great author rather then my explanation. http://blog.sqlauthority.com/2007/07/04/sql-server-definition-comparison-and-difference-between-having-and-where-clause/

Where and having in sql

Answers (2)