**AGGREGATE FUNCTIONS**

Aggregate functions are used to summarize values, such as getting the sum of many rows, the average, etc. Let's go through the most used functions.**AVERAGE**

AVG() is used to get the average of a collection of rows.

Usage: SELECT AVG(colname) FROM ..... [WHERE...]

_________________________________________**COUNT**

COUNT () is used to return the number of rows in a given column or rows that are defined in a WHERE clause.

Usage: SELECT COUNT(colname) FROM ..... [WHERE...]

Using the above syntax will return the number of rows that don't have a NULL value. To return the full number of rows including rows with a NULL value use:

SELECT COUNT(*) FROM .....**_________________________________________****MAX **

MAX() is used to get the greatest value in the column or defined rows.

Usage: SELECT MAX(colname) FROM ..... [WHERE...]

__________________________________**MIN**

MIN() returns the lowest value in the column or defined rows.

Usage: SELECT MAX(colname) FROM ..... [WHERE...]

_________________________________________**SUM**

SUM() Returns the sum of the column or the defined rows.

Usage: SELECT SUM(colname) FROM ..... [WHERE...]

## Wednesday, January 30, 2008

### SQL Basics - Using Aggregate Functions

Posted by Miss Take at 11:38 PM

Labels: SQL Tutorial

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