PI() function in MySQL is used to return the Pi value. The default number of decimal places displayed is seven, but MySQL uses the full double-precision value internally.
Syntax :
PI()
Parameter :
This method does not accept any parameter.
Returns :
It returns the Pi value i.e. 3.141593.
Example-1 :
Returning the default value of Pi using PI Function.
SELECT PI() AS DefaultPiValue;
Output :
Example-2 :
Returning the value of Pi up to 18 decimal places using PI Function .
SELECT PI()+0.000000000000000000
AS PiValue;
Output :
PiValue |
3.141592653589793000 |
Example-3 :
Using PI Function to calculate the area and perimeter of all circles in a column. To demonstrate, let us create a table named Circle.
CREATE TABLE Circle(
Circle_id INT AUTO_INCREMENT,
Radius DECIMAL(10, 3) NOT NULL,
PRIMARY KEY(Circle_id )
);
Now, insert some data to the Circle table.
INSERT INTO Circle(Radius )
VALUES
(2 ),(3),(10 ),(12.5 ),(6.80),
(4.60 ),(6),(20),(25) ;
So, the Circle Table is as follows.
SELECT * FROM Circle;
Circle_id |
Radius |
1 |
2.000 |
2 |
3.000 |
3 |
10.000 |
4 |
12.500 |
5 |
6.800 |
6 |
4.600 |
7 |
6.000 |
8 |
20.000 |
9 |
25.000 |
Now, we will calculate the area and perimeter of every circle using PI function.
SELECT Circle_id, Radius,
PI() * Radius * Radius AS Area,
2 * PI() * Radius AS Perimeter
FROM Circle;
Output :
Circle_id |
Radius |
Area |
Perimeter |
1 |
2.000 |
12.566371 |
12.566371 |
2 |
3.000 |
28.274334 |
18.849556 |
3 |
10.000 |
314.159265 |
62.831853 |
4 |
12.500 |
490.873852 |
78.539816 |
5 |
6.800 |
145.267244 |
42.725660 |
6 |
4.600 |
66.476101 |
28.902652 |
7 |
6.000 |
113.097336 |
37.699112 |
8 |
20.000 |
1256.637061 |
125.663706 |
9 |
25.000 |
1963.495408 |
157.079633 |
Last Updated :
05 Oct, 2020
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