IDataReaderExtension Interface

 

Updated: February 25, 2016

Provides a means of reading one or more forward-only streams of result sets obtained by executing a command at a data source, and is used by SQL Server Reporting Services to retrieve aggregation-specific information about a result set.

Namespace:   Microsoft.ReportingServices.DataProcessing
Assemblies:   Microsoft.ReportingServices.Interfaces (in Microsoft.ReportingServices.Interfaces.dll)
  Microsoft.ReportingServices.SharePoint.UI.WebParts (in Microsoft.ReportingServices.SharePoint.UI.WebParts.dll)

public interface IDataReaderExtension : IDataReader, IDisposable

NameDescription
System_CAPS_pubpropertyAggregationFieldCount

Gets the number of fields by which the data is aggregated.

System_CAPS_pubpropertyFieldCount

Gets the number of fields in the data reader.(Inherited from IDataReader.)

System_CAPS_pubpropertyIsAggregateRow

Indicates whether the current row contains aggregate data.

NameDescription
System_CAPS_pubmethodDispose()

(Inherited from IDisposable.)

System_CAPS_pubmethodGetFieldType(Int32)

Gets the Type information corresponding to the type of object that is returned from GetValue.(Inherited from IDataReader.)

System_CAPS_pubmethodGetName(Int32)

Gets the name of the field to find.(Inherited from IDataReader.)

System_CAPS_pubmethodGetOrdinal(String)

Return the index of the named field.(Inherited from IDataReader.)

System_CAPS_pubmethodGetValue(Int32)

Return the value of the specified field.(Inherited from IDataReader.)

System_CAPS_pubmethodIsAggregationField(Int32)

Indicates whether the data is aggregated by the field with the given index.

System_CAPS_pubmethodRead()

Advances the IDataReader to the next record.(Inherited from IDataReader.)

The IDataReaderExtension interface enables you to implement an extension of the IDataReader interface, which you can use to provide a report server with aggregation information about your result set. For more information about DataReader classes, see Implementing a DataReader Class for a Data Processing Extension.

An application does not create an instance of the IDataReaderExtension interface directly, but creates an instance of a class that implements IDataReaderExtension.

Classes that implement IDataReaderExtension must also implement the required members, and typically define additional members to add provider-specific functionality. Because IDataReaderExtension inherits from IDataReaderExtension, you must also implement all of the IDataReaderExtension members as part of your DataReader class.

Changes made to a result set by another process or thread while data is being read may be visible to the user of a class that implements an IDataReaderExtension. However, the precise behavior is both provider and timing dependent.

Users do not create an instance of a DataReader class directly. Instead, they obtain the DataReader through the ExecuteReader method of the Command object. Therefore, you should mark DataReader constructors as internal.

Return to top
Show: