STDDEVSAMP

Syntax

STDDEVSAMP(expr)

Purpose

This function returns the sample standard deviation of the expression expr.

Examples

1. Enable the ClickHouse extension function mode.

   obclient> ALTER SYSTEM SET sql_func_extension_mode = "ClickHouse";
   

2. Create a test table named test_tbl1.

   obclient> CREATE TABLE test_tbl1 (col1 INT PRIMARY KEY, col2 VARCHAR(50), col3 INT);
   

3. Insert data into the test_tbl1 table.

   obclient> INSERT INTO test_tbl1 VALUES(1, 'a1', 68), (2, 'a2', 88), (3, 'a2', 95);
   

4. Use the STDDEVSAMP function to calculate the standard deviation of the col3 column.

   obclient> SELECT STDDEVSAMP(col3) FROM test_tbl1;
   

   The returned result is as follows:

   +------------------+
   | STDDEVSAMP(col3) |
   +------------------+
   | 14.0118997046558 |
   +------------------+
   1 row in set