lobsample.cpp

vc在线考试系统源码

/*****************************************************************************************
@author  Chandar
@version 1.0
Development Environment        :  Visual C++ 6.0
Name of the File               :  LOBSample.cpp
Creation/Modification History  :
                                  01-Aug-2001     Created
 
Sample Overview
---------------
 This sample uses ADO functionality with OraOLEDB to communicate to database.
 The sample aims at demonstrating the feature of Oracle OLEDB provider for Oracle to 
 pass LOB parameters to and from a database stored procedure. It  also demonstrates
 that Oracle provider for OLEDB bypasses PL/SQL limitation of parameter size greater
 than 32K to a database stored procedure.The image passed to and from the stored procedure 
 could be of size greater than 32K.

 The property 'SPPrmsLOB' is to be set to true when LOB parameter is used in stored
 procedure. The sample shows how to set this property for the command object

 When this application is run, product names are retrieved from "Product_Information" table 
 and shown in the list box in dialog box. When a product is selected from the list its image
 is retrieved from database using stored procedure and displayed in "Existing Image "
 frame.
 
 In case the product image needs to be changed, the user can select an image by clicking
 the "Browse" button, the selected  image from the common file dialog is displayed in the 
 "New Image" frame. To update the  the new image in the database "Update" button can be 
 clicked. The selected image is converted to binary form before insertion.  Then a 
 database stored procedure "setProductImage" is called, to which the selected image is 
 passed as LOB parameter. The image passed to  the stored procedure could be of
 size greater than 32K also. This bypasses the PL/SQL limitation of passing parameters
 greater than 32K.

  Note : The maximum size of image (LOB) that can be passed as  OUT parameter to stored 
         procedure with OraOLEDB is 64K. Images greater than this size may not be
		 retrieved properly from database.

*******************************************************************************************/
#include "stdafx.h"
#include "LOBSample.h"
#include "LOBSampleDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CLOBSampleApp

BEGIN_MESSAGE_MAP(CLOBSampleApp, CWinApp)
	//{{AFX_MSG_MAP(CLOBSampleApp)
		// NOTE - the ClassWizard will add and remove mapping macros here.
		//    DO NOT EDIT what you see in these blocks of generated code!
	//}}AFX_MSG
	ON_COMMAND(ID_HELP, CWinApp::OnHelp)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CLOBSampleApp construction

CLOBSampleApp::CLOBSampleApp()
{
	// TODO: add construction code here,
	// Place all significant initialization in InitInstance
}

/////////////////////////////////////////////////////////////////////////////
// The one and only CLOBSampleApp object

CLOBSampleApp theApp;

/////////////////////////////////////////////////////////////////////////////
// CLOBSampleApp initialization

BOOL CLOBSampleApp::InitInstance()
{
	AfxEnableControlContainer();

	// Standard initialization
	// If you are not using these features and wish to reduce the size
	// of your final executable, you should remove from the following
	// the specific initialization routines you do not need.

#ifdef _AFXDLL
	Enable3dControls();			// Call this when using MFC in a shared DLL
#else
	Enable3dControlsStatic();	// Call this when linking to MFC statically
#endif

	CLOBSampleDlg dlg;       //Create dialog box class object
	m_pMainWnd = &dlg;
    dlg.DoModal();           // Display the dialog box
	

	// Since the dialog has been closed, return FALSE so that we exit the
	//  application, rather than start the application's message pump.
	return FALSE;
}