Assembly: System.Data (in System.Data.dll)
An asynchronous version of ExecuteScalar, which executes the query asynchronously and returns the first column of the first row in the result set returned by the query. Additional columns or rows are ignored.
The cancellation token can be used to request that the operation be abandoned before the command timeout elapses. Exceptions will be reported via the returned Task object.(Overrides DbCommand.ExecuteScalarAsync(CancellationToken).)