What are Aggregate functions

Question

Hi friends Ques : What are Aggregate functions? Explain Aggregate functions in SQL SERVER 2008 with example.

Jignesh Trivedi · Answer

hi SQL Aggregate functions return a single value using values in a table column. following are good article on Aggregate functions in SQL. http://www.mssqltips.com/sqlservertip/1221/sql-server-tsql-aggregate-functions/ http://msdn.microsoft.com/en-us/library/ms173454%28v=sql.110%29.aspx hope this help.

Senthilkumar · Answer

Hi Aggregate function performs calculation of the columns and returns single result. It is very useful to implement the business logic. It is used to get the maximum value of the column or minimum value of the column etc.. There are several types of aggregate functions. AVG MAX MIN SUM COUNT STDEV CHECKSUM_AGG COUNT_BIG STDEVP GROUPING VAR VARP For example COUNT - SELECT COUNT(ProductID) FROM Products WHERE ProductType = 'Consumer' MAX - SELECT MAX(Subject1) FROM Marks WHERE sYear = 2010 MIN - SELECT MIN(Subject5) FROM Marks WHERE sYear = 2011 SUM - SELECT SUM(Amount) FROM Sales WHERE ProductType='Sports' Similarly you can implement other aggregate functions. You can get more details with example in http://msdn.microsoft.com/en-us/library/ms173454(v=sql.110).aspx

Satyapriya Nayak · Answer

Hi Manish Aggregate functions perform a calculation on a set of values and return a single value. With the exception of COUNT aggregate functions ignore null values. Aggregate functions are often used with the GROUP BY clause of the SELECT statement. Please refer the below link http://msdn.microsoft.com/en-us/library/aa258901%28v=sql.80%29.aspx http://databases.about.com/od/sql/l/aaaggregate1.htm Thanks