SqlDataReader.GetFieldValueAsync<T>(Int32, CancellationToken) Method

Definition

Namespace:

Microsoft.Data.SqlClient

Assembly:

Microsoft.Data.SqlClient.dll

Package:

Microsoft.Data.SqlClient v5.2.0

Asynchronously gets the value of the specified column as a type. GetFieldValue<T>(Int32) is the synchronous version of this method.

public:
generic <typename T>
 override System::Threading::Tasks::Task<T> ^ GetFieldValueAsync(int i, System::Threading::CancellationToken cancellationToken);

public override System.Threading.Tasks.Task<T> GetFieldValueAsync<T> (int i, System.Threading.CancellationToken cancellationToken);

override this.GetFieldValueAsync : int * System.Threading.CancellationToken -> System.Threading.Tasks.Task<'T>

Public Overrides Function GetFieldValueAsync(Of T) (i As Integer, cancellationToken As CancellationToken) As Task(Of T)

Type Parameters

T

The type of the value to be returned.

Parameters

i

Int32

The column to be retrieved.

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 IsDBNull(Int32). The returned task must be marked as cancelled.

Returns

Task<T>

The returned type object.

Exceptions

InvalidOperationException

The connection drops or is closed during the data retrieval.

The SqlDataReader 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).

Tried 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.

IndexOutOfRangeException

Trying to read a column that does not exist.

SqlNullValueException

The value of the column was null (IsDBNull(Int32) == true), retrieving a non-SQL type.

InvalidCastException

T doesn't match the type returned by SQL Server or cannot be cast.

Remarks

T can be one of the following types:

Boolean	Byte	Char	DateOnly (.NET 6 or later)
DateTime	DateTimeOffset	Decimal	Double
Float	Guid	Int16	Int32
Int64	SqlBoolean	SqlByte	SqlDateTime
SqlDecimal	SqlDouble	SqlGuid	SqlInt16
SqlInt32	SqlInt64	SqlMoney	SqlSingle
SqlString	Stream	String	TextReader
TimeOnly (.NET 6 or later)	XmlReader		UDT, which can be any CLR type marked with SqlUserDefinedTypeAttribute.

For more information, see SqlClient Streaming Support.