IDataReader-Schnittstelle
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 implemented by Reporting Services Data Processing Extensions that access relational databases.
Namespace: Microsoft.ReportingServices.DataProcessing
Assemblys: Microsoft.ReportingServices.SharePoint.UI.WebParts (in Microsoft.ReportingServices.SharePoint.UI.WebParts.dll)
Microsoft.ReportingServices.Interfaces (in Microsoft.ReportingServices.Interfaces.dll)
Syntax
'Declaration
Public Interface IDataReader _
Inherits IDisposable
'Usage
Dim instance As IDataReader
public interface IDataReader : IDisposable
public interface class IDataReader : IDisposable
type IDataReader =
interface
interface IDisposable
end
public interface IDataReader extends IDisposable
Der IDataReader-Typ macht folgende Elemente verfügbar.
Eigenschaften
Name | Beschreibung | |
---|---|---|
FieldCount | Gets the number of fields in the data reader. |
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Methoden
Name | Beschreibung | |
---|---|---|
Dispose | (Geerbt von IDisposable.) | |
GetFieldType | Gets the Type information corresponding to the type of object that is returned from GetValue. | |
GetName | Gets the name of the field to find. | |
GetOrdinal | Return the index of the named field. | |
GetValue | Return the value of the specified field. | |
Read | Advances the IDataReader to the next record. |
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Hinweise
The IDataReader interface enables you to implement a DataReader class, which provides a means of reading one or more forward-only streams of result sets. For more information about DataReader classes, see Implementieren einer DataReader-Klasse für Datenverarbeitungserweiterungen.
An application does not create an instance of the IDataReader interface directly, but creates an instance of a class that implements IDataReader.
Classes that implement IDataReader must also implement the required members, and typically define additional members to add provider-specific functionality.
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 IDataReader. 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.