How to Calculate a Square Root in SQL Database: MySQL Oracle MS SQL Server PostgreSQL Operators: SQRT Table of Contents Problem: Example: Solution: Discussion: Problem: You want to find the square root of a number in SQ:. Example: You want to compute the square root of all numbers in the column number from the table data. number 9 2 1 0.25 0 -4 Solution: SELECT number, SQRT(number) AS square_root FROM data; The result is: numbersquare_root 93 21.4142135623731 11 0.250.5 00 -4error Discussion: To compute the square root of a number in SQL, use the SQRT() function. This function takes a number as its argument and returns the square root. Note that there is no real square root from a negative number (complex numbers aren't supported) – hence the error. Also, for most numbers (e.g., 2, 2.5, 3, 3.2 etc.) the square root is an irrational number – in the square_root column you won't see the exact results, only the first several digits of their decimal expansion. Recommended courses: SQL Basics Standard SQL Functions Recommended articles: SQL Basics Cheat Sheet Standard SQL Functions Cheat Sheet 24 Rules to the SQL Formatting Standard How Does SQL GROUP BY Work? SQL Numeric Functions See also: How to Round Numbers in SQL How to Floor Numbers in SQL How to Find the Minimum Value of a Column in SQL How to Find the Maximum Value of a Numeric Column in SQL Subscribe to our newsletter Join our monthly newsletter to be notified about the latest posts. Email address How Do You Write a SELECT Statement in SQL? What Is a Foreign Key in SQL? Enumerate and Explain All the Basic Elements of an SQL Query