{"id":3738,"date":"2024-04-04T16:28:04","date_gmt":"2024-04-04T09:28:04","guid":{"rendered":"https:\/\/www.sqlservertutorial.net\/?page_id=3738"},"modified":"2024-04-04T20:01:07","modified_gmt":"2024-04-04T13:01:07","slug":"sql-server-sqrt","status":"publish","type":"page","link":"https:\/\/www.sqlservertutorial.net\/sql-server-math-functions\/sql-server-sqrt\/","title":{"rendered":"SQL Server SQRT() Function"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to use the SQL Server SQRT()<\/code> function to calculate the square root of a number.<\/p>\n\n\n\n

Introduction to the SQL Server SQRT() function #<\/a><\/h2>\n\n\n\n

The SQRT()<\/code> function is a useful mathematical function<\/a> that allows you to calculate the square root of a number.<\/p>\n\n\n\n

The following shows the syntax of the SQRT()<\/code> function:<\/p>\n\n\n

SQRT(number)<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
In this syntax, the number<\/code> can be a float or any number that can be implicitly converted to a float. Also, it can be a numeric expression.<\/p>\n\n\n\n
The SQRT()<\/code> function returns the square root of the number<\/code> with the type of float. It returns NULL if the number is NULL.<\/p>\n\n\n\n
SQL Server SQRT() function examples #<\/a><\/h2>\n\n\n\n
Let’s take some examples of using the SQRT()<\/code> function.<\/p>\n\n\n\n
1) Basic SQRT() function example #<\/a><\/h3>\n\n\n\n
The following statement uses the SQRT()<\/code> function to return the square root of 16:<\/p>\n\n\n
SELECT<\/span> SQRT<\/span>(16<\/span>) AS<\/span> result<\/span>;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Result:<\/p>\n\n\n
result\n------<\/span>\n4.0<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
The query returns 4.0 as the square root of 16.<\/p>\n\n\n\n
2) Using SQRT() function to calculate distance #<\/a><\/h3>\n\n\n\n
First, create a table<\/a> called coordinates<\/code> that stores the x and y-coordinates of points in two-dimensional space:<\/p>\n\n\n
CREATE<\/span> TABLE<\/span> coordinates (\n    id<\/span> INT<\/span> IDENTITY<\/span> PRIMARY KEY<\/span>,\n    x NUMERIC<\/span>,\n    y NUMERIC<\/span>,\n    UNIQUE<\/span> (x, y)\n);<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
INSERT<\/span> INTO<\/span> coordinates (x, y) \nVALUES<\/span>\n    (2<\/span>, 3<\/span>),\n    (-1<\/span>, 7<\/span>),\n    (0<\/span>, 0<\/span>),\n    (9<\/span>, -5<\/span>),\n    (-2.5<\/span>, 3.5<\/span>);<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Third, retrieve data from the coordinates<\/code> table:<\/p>\n\n\n
SELECT<\/span>\n  id<\/span>,\n  x,\n  y\nFROM<\/span>\n  coordinates;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
id | x  | y\n---+----+----\n5  | -3 | 4\n2  | -1 | 7\n3  | 0  | 0\n1  | 2  | 3\n4  | 9  | -5\n(5 rows)<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
Finally, calculate the distance of each point from the origin (0,0) using the SQRT()<\/code> function:<\/p>\n\n\n
SELECT<\/span>\n  SQRT<\/span>(x * x + y * y) AS<\/span> distance\nFROM<\/span>\n  coordinates;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
distance\n--------------------\n5.0\n7.0710678118654755\n0.0\n3.605551275463989\n10.295630140987\n(5 rows)<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
SELECT<\/span>\n  CAST<\/span>(ROUND<\/span>(SQRT<\/span>(x * x + y * y), 2<\/span>) AS<\/span> DEC<\/span>(5<\/span>, 2<\/span>)) AS<\/span> distance\nFROM<\/span>\n  coordinates;<\/code><\/span>Code language:<\/span> SQL (Structured Query Language)<\/span> (<\/span>sql<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
distance\n--------\n5.00\n7.07\n0.00\n3.61\n10.30\n(5 rows)<\/code><\/span>Code language:<\/span> plaintext<\/span> (<\/span>plaintext<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
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  • Use the SQL Server SQRT()<\/code> function to calculate the square root of a number.<\/li>\n<\/ul>\n
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To make the result more readable, you can use the ROUND()<\/a><\/code> function to round the distances to numbers with two precisions and the CAST()<\/a><\/code><\/code> function to cast them to a number with two decimal places.<\/p>\n\n\n
Second, insert some rows<\/a> into the coordinates<\/code> table:<\/p>\n\n\n