Query Task Activity

Description:

Performs an ArcGIS Server query operation.

Inheritance Hierarchy:

System.Object
  System.Activities.Activity
    System.Activities.AsyncCodeActivity
      Geocortex.Workflow.Activities.QueryTask

Function:

This activity performs a query task on an ArcGIS map service, stand-alone table, or feature service. It then returns a feature set.

In a Workflow:

The Query Task activity could be used in a workflow that collected data or geometries from a user using a form, for example. The workflow would then use that data to perform a query using the Query Task activity. Then the results could be sent to the user using the Select Features activity.

Properties:

Name	Description
In Arguments
Credentials	The network credentials that are sent to the host and used to authenticate the request.
Custom Parameters	Additional parameters to include in the request.
Disable Client Caching	If true, adds a timestamp parameter (_ts) to the request to prevent it from being loaded from the application's cache.
GDB Version	The geodatabase version on which the query will be performed. This property is only applicable to feature services only.
Geometry	The geometry to apply to the spatial filter. The spatial relationship as specified by `spatialRelationship` is applied to this geometry while performing the query. The valid geometry types are Envelope, Point, Multipoint, Polyline, or Polygon. The geometry that will be used to filter the query.
Group By Fields for Statistics	The list of fields to group by during statistic analysis.
Layer Id	Obsolete: The ID of the layer to query.
Map Service Url	Obsolete: The URL of the REST MapService layer to query.
Max Allowable Offset	The maximum allowable offset to be used for generalizing geometries returned by the query operation.
Object IDs	The object IDs to query for. If object IDs are specified, other query parameters like Where are ignored.
Order By Fields	The sorting order for the results.
Out Fields	Attribute fields to include in the FeatureSet. Fields must exist in the map layer. You must list the actual field names rather than the alias names. Returned fields are also the actual field names. However, you are able to use the alias names when you display the results. For optimal results, limit the output fields to only those you expect to use. Each query must have access to the Shape and Objectid Fields for a layer, but your list of fields does not need to include these two fields. To return all fields, specify the wildcard `'*'` as the value of this parameter.
Out Spatial Reference	The spatial reference for the returned geometry. If not specified, the geometry is returned in the spatial reference of the underlying service. Requires ArcGIS for Server v.10+.
Out Statistics	The collection of fields to perform statistic analysis on.
Proxy Url	The URL to proxy the request through.
Query Service Url	The URL of the ArcGIS Server query service. For example: http://server/arcgis/rest/services/<serviceName>/MapServer/<layerOrTableId>.
Return Distinct Values	If `true`, the results will contain distinct values based on the fields specified in the Out Fields argument.
Return Geometry	If `true`, each feature in the FeatureSet includes the geometry. Since the geometry makes up a significant portion of the response, only use when you plan to use the geometry of the feature, for example to include them on a map. By default, this is `false`.
Return IDs Only	If `true`, only the object ID of each feature in the FeatureSet is returned. By default, this is `false`. Note that, if `true`, the resulting FeatureSet has limited capabilities. Many common operations on the FeatureSet will fail. For example, the `.Features` property, and the `.Count()` and `.First()` methods will fail. Use the `.ObjectIDs` property to access the ID values. The `.ObjectIDs` property is not safe to use with external activities. To avoid problems create a new variable of type `List<int>` using `.ObjectIDs.Cast(Of Int32).ToList()` immediately following the Query Task activity.
Return M	If `true`, M values will be included in the results if the features have M values.
Return Z	If `true`, Z values will be included in the results if the features have Z values.
Source	The layer source to use when querying a dynamic layer. The Query Service URL must also reference a dynamic layer. For example: http://server/arcgis/rest/services/<serviceName>/MapServer/dynamicLayer.
Spatial Relate Function	The spatial relate function that can be applied while performing the query operation.
Spatial Relationship	The spatial relationship to be held between the input Geometry and each of the returned feature geometries. The default is `esriSpatialRelIntersects`.
Text	Shorthand for a literal search text on the display field, equivalent to: `Where <displayField> like'%%'`. The text is case sensitive. This parameter is ignored if the where parameter is specified. You can determine what the display field is for a layer using the ArcGIS Services Directory.
Time Extent	The time instant or the time extent to query.
Time Option	The time option to use if querying a dynamic layer.
Token	The token for accessing a secure ArcGIS task.
Where	A where clause of the query. Any legal SQL where clause operating on the fields in the layer is allowed, for example: `where=POP2000 >35000`.
Misc
Display Name	QueryTask You can change the name of an activity to one that describes what it does. A descriptive name can make a workflow easier to interpret and maintain.
Out Spatial Reference WKID	Obsolete - This property is no longer supported. Use Out Spatial Reference.
Out Arguments
Exceeded Transfer Limit	Whether the number of records returned has exceeded transfer limit configured by the server administrator (maximum record count).
Results	The FeatureSet returned by the query task.

Version Information:

Supported from: Geocortex Essentials 3.0.