SQRT¶
Returns the square root value of a non-negative numeric expression.
Syntax¶
SQRT( expr )
Arguments¶
Parameter |
Description |
|---|---|
|
Non-negative numeric expression |
Returns¶
Always returns a floating point result of the square root
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 |