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Version: 2.5

std

Description

Returns the standard deviation of an expression. Since v2.5.10, this function can also be used as a window function.

Syntax

STD(expr)

Parameters

expr: the expression. If it is a table column, it must evaluate to TINYINT, SMALLINT, INT, BIGINT, LARGEINT, FLOAT, DOUBLE, or DECIMAL.

Return value

Returns a DOUBLE value.

Examples

Sample dataset

=======
```plaintext
>>>>>>> 41ea837d3 ([Doc] add corr related functions and update window functions (#28776))
MySQL > select * from std_test;
+------+------+
| col0 | col1 |
+------+------+
| 0 | 0 |
| 1 | 2 |
| 2 | 4 |
| 3 | 6 |
| 4 | 8 |
+------+------+

Calculate the standard deviation of col0 and col1.

MySQL > select std(col0) as std_of_col0, std(col1) as std_of_col1 from std_test;
+--------------------+--------------------+
| std_of_col0 | std_of_col1 |
+--------------------+--------------------+
| 1.4142135623730951 | 2.8284271247461903 |
+--------------------+--------------------+

keyword

STD