SQRT
Calculates the square root value of a non-negative numeric expression.
Syntax
SQRT( expr )
Arguments
Parameter |
Description |
---|---|
|
Non-negative numeric expression |
Returns
When using the SQRT
floating point number scalar function, real
arguments are automatically cast to double
precision.
Notes
If the value is NULL, the result is NULL.
If the numeric expression is negative (<0), an error will be shown.
Examples
For these examples, consider the following table and contents:
CREATE TABLE cool_numbers(i INT, f DOUBLE);
INSERT INTO cool_numbers VALUES (1,1.618033), (-12, -34)
, (22, 3.141592), (-26538, 2.7182818284)
, (NULL, NULL), (NULL,1.4142135623)
, (42,NULL), (-42, NULL)
, (-474, 365);
numbers=> SELECT SQRT(2);
sqrt
------------------
1.4142135623730951
Note
Some clients may show fewer digits. See your client settings to change the precision shown.
Replacing negative values with NULL
Combine with CASE
to filter out negative results:
numbers=> SELECT i, SQRT(CASE WHEN i>=0 THEN i ELSE NULL END) FROM cool_numbers;
i | sqrt
-------+-----
1 | 1
-12 |
22 | 4.69
-26538 |
|
|
42 | 6.48
-42 |
-474 |