Average Aggregates - FetchXML Query

Following FetchXML calculates average of estimated value from opportunity.

<fetch distinct='false' mapping='logical' aggregate='true'> 
  <entity name='opportunity'> 
    <attribute name='estimatedvalue' alias='estimatedvalue_avg' aggregate='avg' /> 
  </entity> 
</fetch>

Explanation

To calculate average set following:

• Set aggregate to true in <fetch> clause.

  <fetch distinct='false' mapping='logical' aggregate='true'> 

• In <aggregate> attribute set aggregate to avg

  <attribute name='estimatedvalue' alias='estimatedvalue_avg' aggregate='avg' /> 

Limitation with null values while computing average

Null values are not considered when Microsoft Dynamics CRM computes the average of data. However, zero (0) is used. 
In the following example, with the following data, the average for Account 1 (two entries) is shown as 250 whereas the average for Account 2 (two entries) is shown as 125.

Topic	Potential Customer	Estimated value
Opportunity 1	Account 1	null
Opportunity 2	Account 1	250
Opportunity 3	Account 2	0
Opportunity 4	Account 2	250

- See more at: http://msxrmtools.com/fetchxml/reference