Mega Code Archive

 
Categories / Visual C++ .NET / ADO Database
 

Deal with Blob

#include "stdafx.h" using namespace System; using namespace System::Data; using namespace System::IO; using namespace System::Data::OleDb; void main() {     OleDbConnection^ myConnection = nullptr;     myConnection = gcnew OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Music.mdb");     myConnection->Open();     OleDbCommand^ myCommand = gcnew OleDbCommand("SELECT FileName, MP3 FROM MP3Storage", myConnection);     OleDbDataReader^ myReader = myCommand->ExecuteReader(CommandBehavior::SequentialAccess);     array<unsigned char>^ buffer = gcnew array<unsigned char>(65536);     while ( myReader->Read() ){        String^ fileName = safe_cast<String^>(myReader->GetValue(0));        FileStream^ fileStream = gcnew FileStream(fileName, FileMode::Create);        long long bytesRead, position = 0;        while ( bytesRead = myReader->GetBytes(1, position, buffer,0, buffer->Length) ){           fileStream->Write(buffer, 0, (int)bytesRead);           position += bytesRead;        }        Console::WriteLine("{0} bytes writte to {1} file",position, fileName);        fileStream->Close();     }     myConnection->Close(); }