qrytoolconnectionevents.cpp

Visual C++ 实践与提高--数据库篇的源代码。很好的东西。欢迎下载。

// QryToolConnectionEvents.cpp: implementation of the CQryToolConnectionEvents class.
//

#include "stdafx.h"
#include "QryToolConnectionEvents.h"
#include "MainFrm.h"

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

long CQryToolConnectionEvents::m_lRow = 0;
//////////////////////////////////////////////////////////////////////
// CQryToolConnectionEvents

CQryToolConnectionEvents::CQryToolConnectionEvents(CChildFrame* pChildFrame)
{
	m_pChildFrame = pChildFrame;
}

CQryToolConnectionEvents::~CQryToolConnectionEvents()
{
	m_pChildFrame = NULL;
}

//ExecuteComplete事件响应函数
STDMETHODIMP CQryToolConnectionEvents::ExecuteComplete( 
	LONG RecordsAffected,
	ADOError* pError,
	EventStatusEnum* adStatus,
	_ADOCommand* pCommand,
	_ADORecordset* pRecordset,
	_ADOConnection* pConnection)
{
	OutputDebugString(_T("ExecuteComplete event fired.\n"));

	UNUSED_ALWAYS(adStatus);
	UNUSED_ALWAYS(pError);
	UNUSED_ALWAYS(pCommand);
	UNUSED_ALWAYS(pConnection);
	
	HRESULT hr = S_OK;

	if(m_pChildFrame != NULL && 
		AfxIsValidAddress(m_pChildFrame, sizeof(m_pChildFrame)) != NULL &&
		!m_pChildFrame->m_strSQL.IsEmpty() && !m_pChildFrame->m_bCanceled &&
		m_pChildFrame->m_bExecuting)
	{
		m_pChildFrame->m_ThreadParam.m_strSQL = m_pChildFrame->m_strSQL;
		m_pChildFrame->m_strSQL.Empty();
		m_pChildFrame->m_ThreadParam.m_pFrame = m_pChildFrame;
		ASSERT(m_pChildFrame != NULL);
		m_pChildFrame->m_ThreadParam.m_ptrRS = pRecordset;
		if(m_pChildFrame->m_bProcText)
		{
			m_pChildFrame->m_pThreadExecuteSQL = AfxBeginThread(
				ExecuteSQLProcProc, &m_pChildFrame->m_ThreadParam,
				m_pChildFrame->m_nThreadPriority
				);
		}
		else
		{
			m_pChildFrame->m_ThreadParam.m_pGridCtrl = NULL;
			m_pChildFrame->m_ThreadParam.m_ptrGridCtrl = NULL;
			m_pChildFrame->m_ThreadParam.m_vRowsAffected = RecordsAffected;
			m_pChildFrame->m_pThreadExecuteSQL = AfxBeginThread(
				ExecuteSQLProc, &m_pChildFrame->m_ThreadParam,
				m_pChildFrame->m_nThreadPriority
				);
		}

		ASSERT(m_pChildFrame->m_pThreadExecuteSQL != NULL);
		m_pChildFrame->m_pThreadExecuteSQL->m_pMainWnd = m_pChildFrame;
	}

	return hr;
}
//
UINT ExecuteSQLProc(LPVOID lpVoid)
{
	ThreadParam* pTP = (ThreadParam*)lpVoid;
	CChildFrame* pChildFrame = pTP->m_pFrame;
	ASSERT(pChildFrame != NULL);
	ASSERT(pTP != NULL);
	ASSERT(!pTP->m_strSQL.IsEmpty());
	HRESULT hr = S_OK;
	bool bCaughtException = false;
	try
	{
		hr = CQryToolConnectionEvents::PopulateGrid(pTP);
		if(FAILED(hr))
			_com_issue_error(hr);
	}
	catch(const _com_error& e)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;

			if(pChildFrame->m_strMessages.length())
				pChildFrame->m_strMessages += _T("\n\n");
			CString sBuff = pChildFrame->GetProviderError();
			if(!sBuff.IsEmpty())
				pChildFrame->m_strMessages += sBuff;
			else
				pChildFrame->m_strMessages += pChildFrame->GetComError(e);
		}
	}
	catch(CMemoryException* e)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;

			if(pChildFrame->m_strMessages.length())
				pChildFrame->m_strMessages += _T("\n\n");
			pChildFrame->m_strMessages += _T("Out-of-Memory.");
		}

		if(e)
			e->Delete();
	}
	catch(COleException* e)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;

			if(e)
			{
				TCHAR szMsg[255];
				e->GetErrorMessage(szMsg, 255);
				
				if(pChildFrame->m_strMessages.length())
					pChildFrame->m_strMessages += _T("\n\n");
				pChildFrame->m_strMessages += szMsg;
			}
		}

		if(e)
			e->Delete();
	}
	catch(COleDispatchException* e)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;

			if(e)
			{
				if(pChildFrame->m_strMessages.length())
					pChildFrame->m_strMessages += _T("\n\n");
				pChildFrame->m_strMessages += e->m_strDescription;
			}
		}

		if(e)
			e->Delete();
	}
	catch(LPCTSTR e)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;
		
			if(pChildFrame->m_strMessages.length())
				pChildFrame->m_strMessages += _T("\n\n");
			pChildFrame->m_strMessages += e;
		}
	}
	catch(...)
	{
		if(!pChildFrame->m_bCanceled)
		{
			bCaughtException = true;

			if(pChildFrame->m_strMessages.length())
				pChildFrame->m_strMessages += _T("\n\n");
			pChildFrame->m_strMessages += _T("Errors occurred.");
		}
	}

	try
	{
		if(pChildFrame->m_bIsTSQLSupported && !pChildFrame->m_bCanceled)
		{
			pChildFrame->m_strSQL.Empty();
			if(pTP->m_strSQL.FindNoCase(_T("USE ")) != -1)
			{
				if(!pChildFrame->SelectDataBaseEx())
					TRACE(_T("Error selecting database context.\n"));
			}
		}

		if(pChildFrame->m_bCanceled)
		{
			if(CQryToolConnectionEvents::m_lRow > 1)
				CQryToolConnectionEvents::m_lRow = --CQryToolConnectionEvents::m_lRow;
			if(pTP->m_pGridCtrl != NULL)
				::SendMessage(
					pChildFrame->m_hWnd, WM_SET_GRID_ROWS,
					CQryToolConnectionEvents::m_lRow, pChildFrame->m_bCanceled
					);
		}

		if(pTP->m_ptrGridCtrl != NULL)
		{
			pTP->m_ptrGridCtrl.Release();
			pTP->m_ptrGridCtrl = NULL;
		}
	}
	catch(...)
	{
		TRACE(_T("Errors occurred.\n"));
	}

	try
	{
		::PostMessage(
			pChildFrame->m_hWnd, WM_EXECUTION_COMPLETE, bCaughtException, -1
			);
	}
	catch(...)
	{
		TRACE(_T("Errors occurred.\n"));
	}

	return 0;
}

	CStringEx m_strSQL;
	CChildFrame* m_pFrame;
	CMSFlexGrid* m_pGridCtrl;
	MSFlexGridLib::IMSFlexGridPtr m_ptrGridCtrl;
	ADODB::_RecordsetPtr m_ptrRS;

HRESULT CQryToolConnectionEvents::PopulateGrid(ThreadParam* pTP)
{
	//ThreadParam结构中包含记录集和显示控件等信息
	CChildFrame* pChildFrame = pTP->m_pFrame;
	ASSERT(pChildFrame != NULL);
	//读入记录结果集
	ADODB::_RecordsetPtr ptrRS = pTP->m_ptrRS;
	long lState = ADODB::adStateClosed;
	long nTotalCols = 0;
	long nCols = 0;
	long lRow = 0;
	long lType = ADODB::adEmpty;
	//记录集属性字段
	ADODB::FieldsPtr ptrFields = NULL;
	ADODB::FieldPtr ptrField = NULL;
	//最大记录集数
	long lMaxRows =  700;
	_variant_t vCol((long)-1);
	_variant_t vRowsAffected = pTP->m_vRowsAffected;
	_bstr_t bstrBuff;
	CString sBuff;
	HRESULT hr = S_OK;
	//只要查询没有被结束（m_bCanceled=1表结束），且游标
	//没有指向行集末尾；则查询一直继续。参看while语句。
	do
	{
		hr = ptrRS->get_State(&lState);
		if(FAILED(hr))
			_com_issue_error(hr);
		if(lState == ADODB::adStateClosed)
		{
			if((long)vRowsAffected != -1 && !pChildFrame->m_bExecuteCompleteHandled)
			{
				sBuff.Format(_T("(%d row(s) affected)"), (long)vRowsAffected);
				if(pChildFrame->m_strMessages.length())
					pChildFrame->m_strMessages += _T("\n\n");
				pChildFrame->m_strMessages += sBuff;
			}
		}
		else if(lState == ADODB::adStateOpen &&
			lState != ADODB::adStateClosed)
		{
			ptrFields = ptrRS->Fields;
			nCols = ptrFields->Count; 
			lRow = 0;
			if(!pChildFrame->m_bCanceled && nCols)
			{
				nTotalCols += nCols;
				//向父窗口（CChildFrame）发送WM_GET_GRID_CTRL消息,要求
				//系统创建CMSFlexGri控件实例。
				if(::SendMessage(pChildFrame->m_hWnd, WM_GET_GRID_CTRL,
					nCols, 0L) == -1)
					throw _T("Failed to create grid control.");
				//设置CMSFlexGri控件标头信息
				if(!pChildFrame->m_bCanceled)
					CQryToolConnectionEvents::SetGridHeaderInfo(
						pTP->m_ptrGridCtrl, ptrFields, nCols);

				//以下程序快向控件中添加查询到的记录结果
				if(!pChildFrame->m_bCanceled && ptrRS->State == ADODB::adStateOpen &&
					!ptrRS->adoBOF)
				{
					//向父窗口（CChildFrame）发送WM_SET_GRID_ROWS消息,要求
					//系统为CMSFlexGrid分配存储空间
					if(::SendMessage(pChildFrame->m_hWnd, WM_SET_GRID_ROWS,
						lMaxRows, 0L) == -1)
						throw _T("Unable to Allocate Memory for FlexGrid.");
					
					if(pChildFrame->m_bCanceled)