SqlFileStream Class

Definition

Exposes SQL Server data that is stored with the FILESTREAM column attribute as a sequence of bytes.

public sealed class SqlFileStream : System.IO.Stream
type SqlFileStream = class
    inherit Stream
Public NotInheritable Class SqlFileStream
Inherits Stream
Inheritance
SqlFileStream

Remarks

The SqlFileStream class is used to work with varbinary(max) data stored with the FILESTREAM attribute in a SQL Server 2008 database. You must install the .NET Framework 3.5 SP1 (or later) to use SqlFileStream to work with FILESTREAM data.

Specifying the FILESTREAM attribute on a varbinary(max) column causes SQL Server to store the data in the local NTFS file system instead of in the database file. Transact-SQL statements provide data manipulation capabilities within the server, and Win32 file system interfaces provide streaming access to the data.

Note

Individual files stored in a FILESTREAM column cannot be opened directly from the NTFS file system. Streaming FILESTREAM data works only in the context of a SQL Server transaction.

The SqlFileStream class is derived from the Stream class, which represents an abstraction of a sequence of bytes from some arbitrary data source such as a file or a block of memory. You can read from a FILESTREAM by transferring data from a stream into a data structure such as an array of bytes. You can write to a FILESTREAM by transferring the data from a data structure into a stream. You can also seek within the stream, which allows you to query and modify data at the current position within the stream.

For conceptual documentation and code examples, see FILESTREAM Data.

For documentation about setting up and configuring FILESTREAM data on SQL Server, see Designing and Implementing FILESTREAM Storage in SQL Server 2008 Books Online.

Constructors

SqlFileStream(String, Byte[], FileAccess)

Initializes a new instance of the SqlFileStream class.

SqlFileStream(String, Byte[], FileAccess, FileOptions, Int64)

Initializes a new instance of the SqlFileStream class.

Properties

CanRead

Gets a value indicating whether the current stream supports reading.

CanSeek

Gets a value indicating whether the current stream supports seeking.

CanTimeout

Gets a value indicating whether the current stream can time out.

CanWrite

Gets a value indicating whether the current stream supports writing.

Length

Gets a value indicating the length of the current stream in bytes.

Name

Gets the logical path of the SqlFileStream passed to the constructor.

Position

Gets or sets the position within the current stream.

ReadTimeout

Gets or sets a value, in milliseconds, that determines how long the stream will attempt to read before timing out.

TransactionContext

Gets or sets the transaction context for this SqlFileStream object.

WriteTimeout

Gets or sets a value, in milliseconds, that determines how long the stream will attempt to write before timing out.

Methods

BeginRead(Byte[], Int32, Int32, AsyncCallback, Object)

Begins an asynchronous read operation.

BeginWrite(Byte[], Int32, Int32, AsyncCallback, Object)

Begins an asynchronous write operation.

EndRead(IAsyncResult)

Waits for the pending asynchronous read to complete.

EndWrite(IAsyncResult)

Ends an asynchronous write operation.

Finalize()

Destructor of the SqlFileStream class object.

Flush()

Clears all buffers for this stream and causes any buffered data to be written to the underlying device.

Read(Byte[], Int32, Int32)

Reads a sequence of bytes from the current stream and advances the position within the stream by the number of bytes read.

ReadByte()

Reads a byte from the stream and advances the position within the stream by one byte, or returns -1 if at the end of the stream.

Seek(Int64, SeekOrigin)

Sets the position within the current stream.

SetLength(Int64)

Sets the length of the current stream.

Write(Byte[], Int32, Int32)

Writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.

WriteByte(Byte)

Writes a byte to the current position in the stream and advances the position within the stream by one byte.

Applies to

See also