Union Function (Report Builder and SSRS)

Article
06/13/2017

Returns the union of all the non-null numeric values specified by the expression, evaluated in the given scope.

Note

You can create and modify report definitions (.rdl) in Report Builder and in Report Designer in SQL Server Data Tools. Each authoring environment provides different ways to create, open, and save reports and related items. For more information, see Designing Reports in Report Designer and Report Builder (SSRS) on the Web at microsoft.com.

Syntax

  
Union(expression, scope, recursive)

Parameters

expression
(SqlGeometry or SqlGeography) The expression on which to perform the aggregation.

scope
(String) Optional. The name of a dataset, group, or data region that contains the report items to which to apply the aggregate function. If scope is not specified, the current scope is used.

recursive
(Enumerated Type) Optional. Simple (default) or RdlRecursive. Specifies whether to perform the aggregation recursively.

Return

Returns a spatial object, either SqlGeometry or SqlGeography, based on the expression type. For more information about SqlGeometry and SqlGeography spatial data types, see Spatial Data Types Overview.

Remarks

The set of data specified in the expression must have the same data type.

The value of scope must be a string constant and cannot be an expression. For outer aggregates or aggregates that do not specify other aggregates, scope must refer to the current scope or a containing scope. Dataset scopes are not supported. For aggregates of aggregates, nested aggregates can specify a child scope.

Expression can contain calls to nested aggregate functions with the following exceptions and conditions:

Scope for nested aggregates must be the same as, or contained by, the scope of the outer aggregate. For all distinct scopes in the expression, one scope must be in a child relationship to all other scopes.
Scope for nested aggregates cannot be the name of a dataset.
Expression must not contain First, Last, Previous, or RunningValue functions.
Expression must not contain nested aggregates that specify recursive.

For more information, see Aggregate Functions Reference (Report Builder and SSRS) and Expression Scope for Totals, Aggregates, and Built-in Collections (Report Builder and SSRS).

For more information about recursive aggregates, see Creating Recursive Hierarchy Groups (Report Builder and SSRS).

Example

The following table shows examples of SqlGeometry expressions and Union result expression, shown in WKT (Well Known Text) format for spatial data.

Field with spatial data	Example	Union result
[PointLocation]	POINT(1 2) POINT(3 4)	MULTIPOINT((1 2), (3 4))
[PathDefinition]	LINESTRING(1 2, 3 4) LINESTRING(5 6, 7 8)	MULTILINESTRING((7 8, 5 6), (3 4, 1 2))
[PolygonDefinition]	POLYGON((1 2, 3 4, 5 2, 1 2)) POLYGON((-1 2, -3 4, -5 2, -1 2))	MULTIPOLYGON(((1 2, 5 2, 3 4, 1 2)), ((-5 2, -1 2, -3 4, -5 2)))

=Union(Fields!PointLocation.Value)  
=Union(Fields!PathDefinition.Value)  
=Union(Fields!PolygonDefinition.Value, "Group1")

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