'Declaration Public Overloads Shadows Function ExecuteReaderAsync() As Task(Of TdDataReader)
'Usage Dim instance As TdCommand Dim value As Task(Of TdDataReader) value = instance.ExecuteReaderAsync()
public new Task<TdDataReader> ExecuteReaderAsync()
public: new Task<TdDataReader^>^ ExecuteReaderAsync();
| Exception | Description |
|---|---|
| System.InvalidOperationException | Can be thrown because of one of the following errors:
1) TdCommand.Connection is not in Open state or is null.
2) TdCommand.CommandText is null or empty.
3) TdCommand has an open DataReader.
4) TdCommand has an active request.
5) The local transaction associated with TdCommand is not the same as the local
transaction associated with TdConnection. Assign the local transaction
to the TdCommand.Transaction property. |
| System.ObjectDisposedException | The TdCommand is closed / disposed. |
| TdException | .NET Data Provider for Teradata detected an error. |
Executes the SQL statement (TdCommand.CommandText property) by invoking TdCommand.ExecuteReaderAsync with CommandBehavior.Default and CancellationToken.None. Returns a Task<TdDataReader> representing the asynchronous operation. The task result is the static forward-only result set (TdDataReader).
When TdCommand.CommandType is set to StoredProcedure, any output parameters are populated with data. If the stored procedure does not return a dynamic result set, the resulting TdDataReader contains no rows.
Refer to Returning Data of Output Parameters in a Result Set for more information on the execution of stored procedures.
The .NET Data Provider allows more than one TdDataReader object to be open at any given time for each TdConnection. However, there can only be one TdDataReader for each TdCommand. TdDataReader must be closed before TdCommand can execute another SQL statement.
The .NET Data Provider supports In-Line and Deferred LOB retrievals. Using this method, LOBs are always retrieved in deferred mode, because this method invokes ExecuteReaderAsync(CommandBehavior, CancellationToken) with CommandBehavior.Default.
If this function generates a runtime exception, that exception will be wrapped in an AggregateException within the returned Task:
| Exception | Description |
|---|---|
| IndexOutOfRangeException | Can be thrown because of one of the following errors: 1) The TdParameter.Offset is outside of 0 through array size � 1 2) More in-out/out parameters have been specified than returned from the stored procedure. |
| InvalidCastException | One or more parameters cannot be converted to the Advanced SQL Engine native types. |
| OperationCanceledException | The asynchronous operation was canceled. |
| TdException | The Advanced SQL Engine returned an error, or .NET Data Provider for Teradata detected an error. |
Target Platforms: Windows 8.1, Windows 10, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019