stddev_pop

This function is used to return the deviation of a specified column.

Syntax

stddev_pop(col)

Parameters

**Table 1** Parameter
Parameter	Mandatory	Description
col	Yes	Columns with a data type of numeric. If the value is of any other type, NULL is returned.

Return Values

The return value is of the DOUBLE type.

Example Code

Calculates the deviation of all offering inventories (items). An example command is as follows:
```
select stddev_pop(items) from warehouse; 
```
The command output is as follows:
```
_c0        
1.342355   
```
When used with group by, it groups all offerings by warehouse (warehourseId) and returns the deviation of the offering inventory (items) in the same group. An example command is as follows:
```
select warehourseId, stddev_pop(items) from warehourse group by warehourseId; 
```
The command output is as follows:
```
warehouseId _c1        
city1    1.23124   
city2    1.23344   
city3    1.43425   
```

Parent topic: Aggregate Functions