dbfitter.cpp

VC++6.0压缩ACCESS数据库,压缩数据库

// DBFitter.cpp: implementation of the CDBFitter class.
// Auther : 
//				Hamed M.
// Contact:		
//				[e-mail]
//				[e-mail]
//
// License:		You are free to Use, Modify, Copy, this 
//				program or it's source code. Since this 
//				program is licensed free of charge, there 
//				is no waranty for the program or its source code.
//
//				or as others say:	 This program is provided AS IS
//				WITHOUT  WARRANTY OF  ANY KIND, EITHER EXPRESSED OR 
//				IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
//				WARRANTIES  OF  MERCHANTABILITY  AND  FITNESS FOR A 
//				PARTICULAR  PURPOSE.  THE  ENTIRE  RISK  AS  TO THE 
//				QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.
//
// Disclaimer:  I coppied the above lines(capital letter) from one of
//				those open-source licenses, it is hard to understand 
//				them to me!
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "DBFitter.h"

#import "D:\Program Files\Common Files\system\ado\msado15.dll" rename( "EOF", "MSADO_EOF" )
#import "D:\PROGRAM FILES\COMMON FILES\System\ado\MSJRO.DLL" no_namespace

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

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CDBFitter::CDBFitter()
{
	m_szLastError = "No Error.";
}

CDBFitter::~CDBFitter()
{

}
// Gets a string as apath like 'C:\Hi.txt' and returns file name like: 'Hi.txt'
CString CDBFitter::GetFileName(CString szFullPath)
{
	if (szFullPath.GetLength()==0) {
		return "";
	}

	if (szFullPath.Right(0)=='\\' ) {
		return "";
	}

	int nFindex = szFullPath.ReverseFind('\\');

	if ( nFindex==-1 ) {
		return "";
	}

	return szFullPath.Right(szFullPath.GetLength() - nFindex -1);
}

// Compacts the database file with the path provided with 'szSrcDbPath'
// and copies the compacted file to 'szDstDbPath' the source database
// might or might not have 'szDbPassword' password, but destination
// file will have it.
// The source file will remain UNCOMPACTED, and UNREPAIRED.
BOOL CDBFitter::CompactAndRepair(CString szSrcDbPath, CString szDstDbPath, CString szDbPassword)
{
	if (szSrcDbPath==szDstDbPath) {
		AfxMessageBox("Source and destination can't be the same,\r\n Please use another form of this function with 2 inputs.");
		return FALSE;
	}

	CString	szDbCnn = "",						// To hold database connection string
			szDbTmpCnn = "";					// To hold temporary database connection string
	try
	{
		szDbCnn = "Provider=Microsoft.Jet.OLEDB.4.0;" // Define engine & version
				  "Data Source="+ szSrcDbPath + ";";	  // Define mdb file path
		if (szDbPassword.GetLength()>0) {			  // If password exists, add it
			szDbCnn += ";Jet OLEDB:Database Password=" + szDbPassword;
		}


		szDbTmpCnn = "Provider=Microsoft.Jet.OLEDB.4.0;"
					 "Data Source=" + szDstDbPath + ";"
					 "Jet OLEDB:Engine Type=5;";
		if (szDbPassword.GetLength()>0) {
			szDbTmpCnn += ";Jet OLEDB:Database Password=" + szDbPassword;
		}

		CoInitialize ( NULL );					// This is for COM, I don't understand it actually!

		IJetEnginePtr jet(__uuidof(JetEngine));	// Create a pointer to JetEngine interface

		BSTR									// 2 BSTR variable for the function input
		bszCnn = szDbCnn.AllocSysString(),
		bszTmpCnn = szDbTmpCnn.AllocSysString();

		jet->CompactDatabase(bszCnn, bszTmpCnn);// Do compact and repair database and -
												// create a (compacted) copy.

		SysFreeString(bszCnn);					// Free system allocated memory
		SysFreeString(bszTmpCnn);


		CoUninitialize();
	
	} catch(_com_error &e) {       
												// TODO:		((	WARNING ))
												// The following might lead to memory leak
	
												// UNDONE:
												// Call SysFreeString() , if exception happpend
												// after AllocSysString
		m_szLastError = (LPCTSTR)e.Description( );
		return FALSE;
	}

//	catch(...) {
	// UNDONE: Handle rest of the exceptions
//	}

	return TRUE;
}

// Compacts the database file with the path provided with 'szDbPath'
// The database 'szDbPath' might or might not have 'szDbPassword' 
// password, but destination file will have it just if you provide a
// password as function input.
// A file with the name 'acs_tmp_db_cmpct__rpr.mdb' will be created
// as a temporary file, In the same directory that database exsists
// So there must be enough room for both files and if there is a file
// with this name already, will be deleted.
BOOL CDBFitter::CompactAndRepair(CString szDbPath, CString szDbPassword)
{
	BOOL res;
	CString szTmpDbPath = "";				// To hold the path of the temporary created file

	szTmpDbPath = szDbPath;					// Create a path for a temporary file, just 
											// beside the original file

											// Remove file name to get the folder path
	szTmpDbPath.
		Replace(GetFileName(szDbPath),NULL);
											// A long file name, hoping there is not such 
											// a name already in the folder, or it will be
											// overwritten
	szTmpDbPath += "acs_tmp_db_cmpct__rpr.mdb";

	DeleteFile(szTmpDbPath);				// Delete temporary file, Make sure the file does 
											// NOT exsists before starting the process.

	res = CompactAndRepair(szDbPath, szTmpDbPath, szDbPassword);


	if (FileExists(szTmpDbPath)) {
		DeleteFile(szDbPath);					// Delete source file
		MoveFile(szTmpDbPath, szDbPath);		// Rename temp file to source file
	} else {
		res = FALSE;
		m_szLastError = "Could not find temporary"
			"file. Main file remaind unchanged";
	}

	return res;

}

// Compacts the database file with the path provided with 'szDbPath'
// The database 'szDbPath' should not have any password,
// A file with the name 'acs_tmp_db_cmpct__rpr.mdb' will be created
// as a temporary file, In the same directory that database exsists
// So there must be enough room for both files and if there is a file
// with this name already, it will be deleted.
BOOL CDBFitter::CompactAndRepair(CString szDbPath)
{
	return CompactAndRepair(szDbPath, "");
}

CString CDBFitter::GetLastErrString()
{
	return m_szLastError;
}

BOOL CDBFitter::FileExists(CString szPath)
{
	CFile f;
	CFileStatus fs;

	if (!f.GetStatus(szPath,fs)) {
		return FALSE;
	}

	return TRUE;
}