SQL Server SQRT() Function

SQRT() is a mathematical function in SQL Server used to calculate the square root of a given number. This function takes a numeric expression as its argument and returns the positive square root of the number.

Syntax

The syntax of the SQRT() function is as follows:

SQRT(numeric_expression)

Here, numeric_expression is a numeric expression representing the number for which to calculate the square root.

Usage

The SQRT() function is typically used in mathematical operations or statistical analysis of data. For example, in calculating variance or standard deviation, the square root function is needed.

Examples

Here are two examples using the SQRT() function:

Example 1

Suppose there is a column sales that contains sales data for a company for the past five years, as shown below:

sales
1000
2000
3000
4000
5000

To calculate the standard deviation of these sales, the following query can be used:

SELECT STDEV(sales) AS 'Standard Deviation'
FROM sales_data;

The query result is as follows:

Standard Deviation
1581.13883008419

Example 2

Suppose there is a column prices that contains price data for a product on an e-commerce platform, as shown below:

prices
10.5
20.3
30.1
15.2
25.8

To calculate the mean and standard deviation of these prices, the following query can be used:

SELECT AVG(prices) AS 'Average Price', STDEV(prices) AS 'Standard Deviation'
FROM prices_data;