DbDataReader.IsDBNullAsync Method (Int32, CancellationToken)

.NET Framework (current version)

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

Namespace:   System.Data.Common
Assembly:  System.Data (in System.Data.dll)

public virtual Task<bool> IsDBNullAsync(
	int ordinal,
	CancellationToken cancellationToken


Type: System.Int32

The zero-based column to be retrieved.

Type: System.Threading.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. The returned task must be marked as cancelled.

Return Value

Type: System.Threading.Tasks.Task<Boolean>

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

Exception Condition

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.


Trying to read a column that does not exist.

For more information, see SqlClient Streaming Support.

Universal Windows Platform
Available since 10
.NET Framework
Available since 4.5
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