DbDataReader.IsDBNullAsync DbDataReader.IsDBNullAsync DbDataReader.IsDBNullAsync DbDataReader.IsDBNullAsync Method

Definition

An asynchronous version of IsDBNull(Int32), which gets a value that indicates whether the column contains non-existent or missing values.

Overloads

IsDBNullAsync(Int32, CancellationToken) IsDBNullAsync(Int32, CancellationToken) IsDBNullAsync(Int32, CancellationToken)

An asynchronous version of IsDBNull(Int32), which gets a value that indicates whether the column contains non-existent or missing values. Optionally, sends a notification that operations should be cancelled.

IsDBNullAsync(Int32) IsDBNullAsync(Int32) IsDBNullAsync(Int32) IsDBNullAsync(Int32)

An asynchronous version of IsDBNull(Int32), which gets a value that indicates whether the column contains non-existent or missing values.

IsDBNullAsync(Int32, CancellationToken) IsDBNullAsync(Int32, CancellationToken) IsDBNullAsync(Int32, CancellationToken)

An asynchronous version of IsDBNull(Int32), which gets a value that indicates whether the column contains non-existent or missing values. Optionally, sends a notification that operations should be cancelled.

public:
 virtual System::Threading::Tasks::Task<bool> ^ IsDBNullAsync(int ordinal, System::Threading::CancellationToken cancellationToken);
public virtual System.Threading.Tasks.Task<bool> IsDBNullAsync (int ordinal, System.Threading.CancellationToken cancellationToken);
abstract member IsDBNullAsync : int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<bool>
override this.IsDBNullAsync : int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<bool>

Parameters

ordinal
Int32 Int32 Int32 Int32

The zero-based column to be retrieved.

cancellationToken
CancellationToken CancellationToken CancellationToken CancellationToken

The cancellation instruction, which propagates a notification that operations should be canceled. This does not guarantee the cancellation. A setting of CancellationToken.None makes this method equivalent to IsDBNullAsync(Int32). The returned task must be marked as cancelled.

Returns

true if the specified column value is equivalent to DBNull otherwise false.

Exceptions

The connection drops or is closed during the data retrieval.

The DbDataReader is closed during the data retrieval.

There is no data ready to be read (for example, the first Read() hasn't been called, or returned false).

Trying to read a previously read column in sequential mode.

There was an asynchronous operation in progress. This applies to all Get* methods when running in sequential mode, as they could be called while reading a stream.

Remarks

For more information, see SqlClient Streaming Support.

IsDBNullAsync(Int32) IsDBNullAsync(Int32) IsDBNullAsync(Int32) IsDBNullAsync(Int32)

An asynchronous version of IsDBNull(Int32), which gets a value that indicates whether the column contains non-existent or missing values.

public:
 System::Threading::Tasks::Task<bool> ^ IsDBNullAsync(int ordinal);
public System.Threading.Tasks.Task<bool> IsDBNullAsync (int ordinal);
member this.IsDBNullAsync : int -> System.Threading.Tasks.Task<bool>
Public Function IsDBNullAsync (ordinal As Integer) As Task(Of Boolean)

Parameters

ordinal
Int32 Int32 Int32 Int32

The zero-based column to be retrieved.

Returns

true if the specified column value is equivalent to DBNull otherwise false.

Exceptions

The connection drops or is closed during the data retrieval.

The DbDataReader is closed during the data retrieval.

There is no data ready to be read (for example, the first Read() hasn't been called, or returned false).

Trying to read a previously read column in sequential mode.

There was an asynchronous operation in progress. This applies to all Get* methods when running in sequential mode, as they could be called while reading a stream.

Remarks

For more information, see SqlClient Streaming Support.

Applies to