How to Calculate a Square in SQL

Problem

You want to find the square of a number in SQL.

Example

You want to compute the square of each number in the column number from the table data.

Solution 1: Use SQUARE function

SELECT
  number,
  SQUARE(number) AS square
FROM data;

Solution 2: Use multiplication operator *

SELECT
  number,
  number * number AS square
FROM data;

Solution 3: Use POWER function

SELECT
  number,
  POWER(number, 2) AS square
FROM data;

The result is:

Discussion

One way to compute the square of a number in SQL is to use the SQUARE() function. It takes a number as an argument and returns the squared number.

The square of a number can also be computed as number * number, so another way is to simply use this expression; no additional function is needed.

The third way to compute the square of a number is to use the POWER() function. This function takes a number and a power as arguments and returns the powered number. Here, you need to compute the square, so the power is 2. So, you have POWER(number, 2).

Similarly, you can calculate any power of a number, e.g. the third power.

SELECT
  POWER(number, 3) AS third_power
FROM data;

The result will be: