// ADODBUtil.cpp: implementation of the CADODBUtil class.
//
//////////////////////////////////////////////////////////////////////

#include "ABDBUtil.h"
#include <string>


CABDBUtil* CABDBUtil::m_Instance = NULL;

CABDBUtil::CABDBUtil()
{
	InitADOConnect();

}

CABDBUtil::~CABDBUtil()
{
	ExitConnect();
}


void CABDBUtil::InitADOConnect()
{
	//初始化ole/com库环境
	//	AfxOleInit();
	::CoInitialize(NULL);
	HRESULT hr;
		
	try
	{
		//创建Connection
		hr=m_pConnection.CreateInstance("ADODB.Connection");

		//设置链接字符串,必须是BSTR或者_bstr_t
		if(SUCCEEDED(hr))
		{
			_bstr_t FileName = ".\\AllData.mdb";
			_bstr_t strConnect="Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +FileName;
			hr=m_pConnection->Open(strConnect,"","",adModeUnknown);
		}
		
	}
	
	//捕捉异常
	catch (_com_error e)
	{
		;
	}
}

bool CABDBUtil::Query(_bstr_t bstrSQL)
{
	try
	{
		//链接数据库，如果connection对象空，则重新链接数据库
		if (m_pConnection==NULL)
			InitADOConnect();

		//创建记录集对象
		m_pRecordset.CreateInstance(_uuidof(Recordset));


		//取得标准记录
		m_pRecordset->Open(bstrSQL,m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
	
		return true;
	}
	catch (_com_error e)
	{
		return false;
		
	}
}


bool CABDBUtil::ExecuteSQL(_bstr_t bstrSQL)
{
	try
	{
		//是否以及链接数据库
		if (m_pConnection==NULL)
			InitADOConnect();
		m_pConnection->Execute(bstrSQL,NULL,adCmdText);
		return true;
	}
	catch (_com_error e)
	{

		return false;
		
	}
}

void CABDBUtil::ExitConnect()
{
	//关闭记录集和连接
	if(m_pRecordset!=NULL)
		m_pRecordset->Close();
	m_pConnection->Close();
	::CoUninitialize();//是放环境
}


void CABDBUtil::Release()
{
	if (m_Instance)
	{
		delete m_Instance;
		m_Instance = NULL;
	}
}

CABDBUtil* CABDBUtil::GetInstance()
{
	if (m_Instance==NULL)
	{
		m_Instance = new CABDBUtil();
	}

	return m_Instance;
}

std::string CABDBUtil::GetLastError()
{
	return m_LastError;
}