Aggregate Function (Reporting Services)
Returns a custom aggregate of the specified expression, as defined by the data provider.
An expression that evaluates to numeric data on which to perform the aggregation. The expression must be a simple field reference.
(String) The name of a dataset, grouping, or data region that contains the report items to which to apply the aggregate function. If Scope is specified, the aggregate function applies to all data in the dataset, grouping, or data region. All group expressions for the specified scope must contain simple field references. For more information about the Scope parameter, see Using Report Functions in Expressions (Reporting Services).
All containing groups for the item that uses this function must have simple field references as their group expressions. The difference between the Aggregate function and the Sum report functions is that the aggregated values are calculated in the data processing extension and returned as part of the dataset, whereas the Sum function processes the contents of detail rows and calculates the result.
Scope cannot be an expression.
The following code example provides a custom aggregation of line item totals in the Order grouping or data region.