Visual C++ .NET/Database ADO.net/OleDbCommand

Using database Commands

<source lang="csharp">

1. include "stdafx.h"

using namespace System; using namespace System::Data; 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 = myConnection->CreateCommand();
   myCommand->CommandText = "SELECT COUNT(*) FROM Music";
   myCommand = gcnew OleDbCommand("SELECT COUNT(*) FROM Music",myConnection);
   Object^ count = myCommand->ExecuteScalar();
   Console::WriteLine("There are {0} songs in the Music table", count);
   myCommand->CommandText ="DELETE FROM Music WHERE Genre="N"";
   int RecordsAffected = myCommand->ExecuteNonQuery();
   Console::WriteLine("{0} songs were deleted from the Music table",RecordsAffected);
   myConnection->Close();

}

 </source>

Using database Parameter

<source lang="csharp">

1. include "stdafx.h"

using namespace System; using namespace System::Data; 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 COUNT(*) FROM Music WHERE Genre=@Genre",myConnection);
   OleDbParameter^ parameter = gcnew OleDbParameter("@Genre",OleDbType::Char);
   parameter->Direction = ParameterDirection::Input;
   parameter->Value = "Techno/Classical";
   MyCommand->Parameters->Add(parameter);
   Object^ Count = MyCommand->ExecuteScalar();
   Console::WriteLine("Count = {0}", Count);
   myConnection->Close();

}

 </source>