AVG
Returns the average of all values in a group of rows. Optionally, you can apply a filter to limit the rows you read to calculate the average. You can nest only one other aggregate function within AVG, and the nested function must return a Numeric datatype.
Use only in Mapping Configuration tasks.
Syntax
AVG( numeric_value [, filter_condition ] )
Argument | Required/ Optional | Description |
|---|
numeric_value | Required | Numeric datatype. Passes the values for which you want to calculate an average. You can enter any valid transformation expression. |
filter_condition | Optional | Limits the rows in the search. The filter condition must be a numeric value or evaluate to TRUE, FALSE, or NULL. You can enter any valid transformation expression. |
Return Value
Numeric value.
NULL if all values passed to the function are NULL or if no rows are selected. For example, the filter condition evaluates to FALSE or NULL for all rows.
Nulls
If a value is NULL, AVG ignores the row. However, if all values passed are NULL, AVG returns NULL.
Group By
AVG groups values based on group by fields you define in the transformation, returning one result for each group.
If there is not a group by field, AVG treats all rows as one group, returning one value.
Example
The following expression returns the average wholesale cost of flashlights:
AVG( WHOLESALE_COST, ITEM_NAME='Flashlight' )
ITEM_NAME | WHOLESALE_COST |
|---|
Flashlight | 35.00 |
Navigation Compass | 8.05 |
Regulator System | 150.00 |
Flashlight | 29.00 |
Depth/Pressure Gauge | 88.00 |
Flashlight | 31.00 |
RETURN VALUE: 31.66
| |
Tip
You can perform arithmetic on the values passed to AVG before the function calculates the average. For example:
AVG( QTY * PRICE - DISCOUNT )