The PI() function is used to return the value of π (pi), a mathematical constant representing the ratio of a circle's circumference to its diameter.
Syntax
PI()
Definition and Usage
- Returns the value of π (approximately 3.141593).
- Commonly used in mathematical calculations involving circles or trigonometry.
- It is a constant, and the result is always the same.
Technical Details
- Introduced in: MySQL 4.0
- Return Value: A floating-point number representing π.
Examples
Example 1: Retrieve the value of π
SELECT PI() AS PiValue;
Output:
PiValue
--------
3.141593
Example 2: Calculate the circumference of a circle
To calculate the circumference of a circle with a radius of 5:
SELECT 2 * PI() * 5 AS Circumference;
Output:
Circumference
--------------
31.415926
Example 3: Calculate the area of a circle
To calculate the area of a circle with a radius of 3:
SELECT PI() * POW(3, 2) AS Area;
Output:
Area
-----
28.274334
Related Functions
DEGREES(): Converts a value in radians to degrees.RADIANS(): Converts a value in degrees to radians.POW(): Returns a number raised to the power of another number.
The PI() function is essential for geometric and trigonometric calculations in MySQL.