Visual C++ .NET/Database ADO.net/OleDbCommand
Using database Commands
<source lang="csharp">
- 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">
- 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>