Open File Stream Win API
-
21-09-2019 - |
문제
I'm trying to use the
OpenSqlFilestream
Instruction but my code did not recognise it
What dll i have to load in order to use it?
Dear marc_s look at my code
Public Sub WriteFileStream(ByVal imSource As Byte(), ByVal imSize As Integer, ByVal imTy As Type, ByVal sender As Object, ByVal e As EventArgs)
Dim subProvider As String = Nothing
Dim subDataSource As Object = Nothing
Dim subUid As String = Nothing
Dim subPwd As String = Nothing
Dim subDataBase As String = Nothing
Dim subPSI As Boolean = Nothing
Dim ParamXML() As String = Nothing
Dim TypeOfServer As String = "Remote"
Dim imParam(3) As String
Dim imTable(1) As String
Dim RemoteSQLcmd As SqlCommand = New SqlCommand
Dim tokenReader As SqlDataReader
'-------------------------------------------------'
Dim AbsRecord As Int64 = 0
Dim VarString(10) As String
Dim VarInt(10) As Integer
'-------------------------------------------------'
ParamXML = Split(loadXmlFile(TypeOfServer, sender, e), "|")
subUid = ParamXML(3)
subProvider = ParamXML(0)
subDataSource = ParamXML(1)
subDataBase = ParamXML(2)
subPwd = ParamXML(4)
subPSI = ParamXML(5)
Dim SchemaID As String = Convert.ToInt16(ParamXML(8))
Dim SchemaName As String = Nothing
If SchemaID = 1 Then
SchemaName = subUid
ElseIf SchemaID = 2 Then
SchemaName = "dbo"
ElseIf SchemaID = 0 Then
SchemaName = "dbo"
End If
'-------------------------------------------------'
imTable(0) = "tPDetails"
imTable(1) = "tPImages"
Try
imParam(0) = Me.TextBox1.Text.Trim.ToString 'Name'
imParam(1) = Me.TextBox2.Text.Trim.ToString 'Code'
imParam(2) = Me.TextBox3.Text.Trim.ToString 'Price'
imParam(3) = Me.TextBox4.Text.Trim.ToString 'Comments'
'========================================================'
If RemoteSQLConn.State = ConnectionState.Open Then RemoteSQLConn.Close()
SQL_Connection(TypeOfServer, TypeOfServer & "Conn.xml", sender, e)
RemoteSQLConn.open()
'----------------------'
Dim imHolder As Image = Image.FromStream(imStream)
Dim imHeight As Integer = imHolder.Height
Dim imWidth As Integer = imHolder.Width
Dim imLength As Integer = imHolder.PropertyItems.Length
Dim imType As Type = imTy
'----------------------'
Dim FirstColumnNames As String = _
imTable(0) & "_Code, " & _
imTable(0) & "_Price, " & _
imTable(0) & "_Title, " & _
imTable(0) & "_Type, " & _
imTable(0) & "_Height, " & _
imTable(0) & "_Width, " & _
imTable(0) & "_Stock, " & _
imTable(0) & "_Comments "
Dim FirstFieldsValues As String = "'" & imParam(1) & "', '" & _
imParam(2) & "', '" & _
imParam(0) & "', '" & _
imType.ToString & "', '" & _
imHeight & "', '" & _
imWidth & "', '" & _
"0', '" & _
imParam(3) & "' "
'--------------------------------------------'
RemoteSQLcmd = New SqlCommand("INSERT INTO " & _
SchemaName & "." & imTable(0) & " (" & FirstColumnNames & ") VALUES (" & FirstFieldsValues & ") ", RemoteSQLConn)
RemoteSQLcmd.ExecuteNonQuery()
'--------------------------------------------------'
RemoteSQLcmd = New SqlCommand("SELECT * FROM " & SchemaName & "." & imTable(0) & _
" WHERE " & imTable(0) & "_Code = " & "'" & imParam(1) & "'", RemoteSQLConn)
AbsRecord = RemoteSQLcmd.ExecuteScalar
'--------------------------------------------------'
RemoteSQLcmd = New SqlCommand("INSERT INTO " & SchemaName & "." & imTable(1) & " VALUES (newid(), " & AbsRecord & ", CAST('' as varbinary(max)))", RemoteSQLConn)
RemoteSQLcmd.ExecuteNonQuery()
'--------------------------------------------------'
RemoteSQLcmd = New SqlCommand("SELECT " & imTable(1) & "_Image.PathName() FROM " & _
SchemaName & "." & imTable(1) & " WHERE " & imTable(1) & "_" & imTable(0) & "_ID = " & AbsRecord, RemoteSQLConn)
Dim filePathName As String = Nothing
Dim pathObj As Object = RemoteSQLcmd.ExecuteScalar()
'-------------------------------------------------- Path Name '
If Not pathObj.Equals(DBNull.Value) Then
filePathName = DirectCast(pathObj, String)
Else
Throw New System.Exception("Image.PathName() failed to read the path name for the Image column.")
End If
'-------------------------- GET_FILESTREAM_TRANSACTION_CONTEXT()'
Dim RemoteSQLtx As SqlTransaction = RemoteSQLConn.BeginTransaction("MainTranaction")
RemoteSQLcmd.Transaction = RemoteSQLtx
RemoteSQLcmd = New SqlCommand("SELECT GET_FILESTREAM_TRANSACTION_CONTEXT()", RemoteSQLConn, RemoteSQLtx)
Dim tokenObject As Object = RemoteSQLcmd.ExecuteScalar()
'-------------------------------------- File Token '
tokenReader = RemoteSQLcmd.ExecuteReader(CommandBehavior.SingleRow)
tokenReader.Read()
Dim txContext As SqlBinary = DirectCast(tokenObject, Byte())
tokenReader.Close()
'-----------------------------------------------'
Try
'-------------------- Closing all connections'
If RemoteSQLConn.State = ConnectionState.Open Then RemoteSQLConn.Close()
If RemoteSQLcmd.Connection.State = ConnectionState.Open Then RemoteSQLcmd.Connection.Close()
If RemoteConnInfo.State = ConnectionState.Open Then RemoteConnInfo.Close()
RemoteSQLtx.Dispose() '.Connection.State = ConnectionState.Open Then RemoteSQLtx.Connection.Close()
'-------------------- Open connections for Indegrated Security''
ChangeLoginPerson("PRINCIDEVEL\Administrator")
RemoteConnInfo.ConnectionString = "Provider=" & subProvider & "; Data Source=" & subDataSource & _
"; Database=" & subDataBase & "; Integrated Security=" & "SSPI" & "; Persist Security Info=" & subPSI
RemoteSQLcmd.Connection.Open()
RemoteSQLConn = New SqlConnection("Server=" & subDataSource & "; Integrated Security=TRUE" & "; database=" & subDataBase)
RemoteSQLConn.Open()
RemoteSQLtx = RemoteSQLConn.BeginTransaction("MainTranaction")
RemoteSQLcmd.Transaction = RemoteSQLtx
'------------------------- Write in to file stream ---------------'
Dim imImage As Byte() = New Byte(imStream.Length) {}
Dim bytesRead As Integer = imStream.Read(imImage, 0, imStream.Length)
Dim sqlFile As New SqlFileStream(filePathName, txContext, FileAccess.ReadWrite, FileOptions.WriteThrough, 0)
Dim numBytes As Integer = 0
Dim unicode As Encoding = Encoding.GetEncoding(0)
While bytesRead > 0
sqlFile.Write(imImage, 0, bytesRead)
bytesRead = imStream.Read(imImage, 0, imSize)
End While
RemoteSQLtx.Commit()
RemoteSQLcmd.Transaction.Commit()
sqlFile.Close()
Catch FsEx As Exception
MessageBox.Show(FsEx.Message, "Write in SQL File Stream ", MessageBoxButtons.OK, MessageBoxIcon.Stop)
Finally
End Try
'--------------------------------------------------'
Catch ex As Exception
MessageBox.Show(ex.Message, "WriteFileStream ", MessageBoxButtons.OK, MessageBoxIcon.Stop)
Finalize()
Finally
RemoteSQLConn.Close()
imStream.Close()
End Try
End Sub
해결책
Do you do all the necessary steps before opening the file stream? Grabbing the context inside a transaction??
Check out this article here for a detailed discussion as to how to do it. Here's another blog post with a VB.NET sample code snippet.
Update: Lefteris, your code snippet is very very hard to read and understand, I did my best, but I'm really not sure. What I'm thinking is that you close the transaction too quickly. You seem to create a connection and a transaction to get the GET_FILESTREAM_TRANSACTION_CONTEXT, but then you close that again before you actually write out your bytes. I think the transaction should span all operations - it should start before you get the transaction context, and it should stay alive for the whole write operation, and only be committed once the whole write operation is done.
I tried to come up with a simpler code snippet to show you - it's in C#, since I couldn't convert it back to VB.NET:
public static void WriteFileStream(byte[] imSource, int imSize)
{
// use your own SQL insert command here instead
const string InsertCmd = "INSERT INTO PhotoAlbum(PhotoId, Description)" +
" VALUES(@PhotoId, @Description)";
using (SqlConnection conn = new SqlConnection(ConnStr))
{
conn.Open();
// create transaction here and let it stay alive!
using (SqlTransaction txn = conn.BeginTransaction())
{
using (SqlCommand cmd = new SqlCommand(InsertCmd, conn, txn))
{
cmd.Parameters.Add("@PhotoId", SqlDbType.Int).Value = photoId;
cmd.Parameters.Add("@Description", SqlDbType.VarChar).Value = desc;
cmd.ExecuteNonQuery();
}
SafeFileHandle handle = GetOutputFileHandle(photoId, txn);
MemoryStream inputStream = new MemoryStream(imSource);
using (FileStream dest = new FileStream(handle, FileAccess.Write))
{
byte[] buffer = new byte[BlockSize];
int bytesRead;
while ((bytesRead = inputStream.Read(buffer, 0, buffer.Length)) > 0)
{
dest.Write(buffer, 0, bytesRead);
}
dest.Close();
}
inputStream.Close();
// commit transaction here, after all is done
txn.Commit();
}
conn.Close();
}
}
This is adapted from the blog post SQL Server 2008 FILESTREAM Part 3: OpenSqlFileStream API - check that out by all means!