網上關于ADO的使用方法很多，這邊我個人就整理出一個使用ADO的方法的具體步驟：
1、用#import引入ADO庫文件
在stdafx.h文件中添加#import "c:\program files\common files\system\ado\msado15.dll"no_namespaces rename("EOF" adoEOF")
2、 數據庫連接，創建CDBConnection，代碼如下：
class CDBConnection
{
public:
//數據庫是否已連接
BOOL m_Actived;
//關閉連接
void Close();
//打開連接
BOOL Open(CString CnnStr);
//ADO的連接對象指針
_ConnectionPtr m_pConn;
CDBConnection();
virtual ~CDBConnection();
};
CDBConnection::CDBConnection()
{
//創建連接對象
m_pConn.CreateInstance("ADODB.Connection");
m_Actived = FALSE;
}
CDBConnection::~CDBConnection()
{
//釋放連接對象
m_pConn.Release();
}
BOOL CDBConnection::Open(CString CnnStr)
{
try
{
m_pConn->Open(_bstr_t(CnnStr), "", "", adConnectUnspecified);
m_Actived = TRUE;
return TRUE;
}
catch(_com_error &e)
{
return FALSE;
}
}
void CDBConnection::Close()
{
if (m_Actived)
{
m_pConn->Close();
m_Actived = FALSE;
}
}
相關函數：
1）HRESULT Connection15::Open ( _bstr_t ConnectionString, _bstr_t UserID, _bstr_t Password, long Options )
ConnectionString例子："Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strCommandLine + "WhMgrDB.mdb;Persist Security Info=False"。其中strCommandLine 為數據庫的地址，WhMgrDB.mdb為所要用到的數據庫。
UserID和Password分別為建立連接時所使用的用戶名和密碼
Options：決定是使用同步方式（adConnectUnspecified默認）還是異步方式（adAsyncConnext）打開數據庫。當使用同步方式打開數據庫時，只有打開完成，Open方法才返回；而是用異步方式打開數據庫時，Open方法在建立連接完成之前就返回。
3、 通用數據訪問模塊的實現
class CDataSet
{
protected:
//打開查詢
BOOL Open(CString SQL);
public:
//刪除當前記錄
void Delete();
//更新記錄
void Update();
//將Field列的值設置為Value
void SetAsString(CString Field, CString Value);
//關閉查詢
void Close();
//加載數據
virtual BOOL LoadData();
//得到Field列的值
CString GetAsString(CString FieldName);
//是否在第一條記錄之前
BOOL IsBOF();
//是否在最后一條記錄之后
BOOL IsEOF();
//移動到上一條記錄
void MovePrevious();
//移動到下一條記錄
void MoveNext();
//移動到最后一條記錄
void MoveLast();
//移動到第一條記錄
void MoveFirst();
//數據庫連接對象
CDBConnection * m_cnn;
CDataSet();
virtual ~CDataSet();
private:
BOOL m_Actived;
_RecordsetPtr m_pRs;
};
CDataSet::CDataSet()
{
m_pRs.CreateInstance("ADODB.RecordSet");
m_Actived = FALSE;
}
CDataSet::~CDataSet()
{
m_pRs.Release();
}
BOOL CDataSet::Open(CString SQL)
{
ASSERT(m_cnn);
ASSERT(m_cnn->m_Actived);
try
{
m_pRs->Open(_variant_t(SQL), _variant_t(m_cnn->m_pConn, true), adOpenStatic, adLockOptimistic, adCmdText);
m_Actived = TRUE;
return TRUE;
}
catch(_com_error &e)
{
return FALSE;
}
}
void CDataSet::MoveFirst()
{
m_pRs->MoveFirst();
}
void CDataSet::MoveLast()
{
m_pRs->MoveLast();
}
void CDataSet::MoveNext()
{
m_pRs->MoveNext();
}
void CDataSet::MovePrevious()
{
m_pRs->MovePrevious();
}
BOOL CDataSet::IsEOF()
{
return m_pRs->EndOfFile;
}
BOOL CDataSet::IsBOF()
{
return m_pRs->BOF;
}
CString CDataSet::GetAsString(CString FieldName)
{
ASSERT(!IsBOF() && !IsEOF());
_variant_t vValue = m_pRs->Fields->Item[_variant_t(FieldName)]->Value;
//如果為空值則返回空
if ((V_VT(&vValue) == VT_NULL) || (V_VT(&vValue) == VT_EMPTY))
{
return "";
}
return _com_util::ConvertBSTRToString(_bstr_t(vValue));
}
BOOL CDataSet::LoadData()
{
return FALSE;
}
void CDataSet::Close()
{
if (m_Actived)
{
m_pRs->Close();
}
}
void CDataSet::SetAsString(CString Field, CString Value)
{
ASSERT(!IsBOF() && !IsEOF());
m_pRs->Fields->Item[_variant_t(Field)]->Value = _variant_t(Value);
}
void CDataSet::Update()
{
m_pRs->Update();
}
void CDataSet::Delete()
{
m_pRs->Delete(adAffectCurrent);
}
相關函數：
1）HRESULT Recordset15::Open ( const _variant_t & Source, const _variant_t & ActiveConnection, enum CursorTypeEnum CursorType, enum LockTypeEnum LockType, long Options )
Source:變體型，計算Command對象的變量名、SQL語句、表名、存儲過程調用或持久Recordset文件名。
ActiveConnection：計算有效地Connection對象變量名或字符串，包含ConnectionString參數。
CursorType：確定提供者打開Recordset時應該使用的游標類型。
LockType：adLockReadOnly（默認值，只讀）、adLockPessimistic（保守式鎖定）、adLockOptimistic（開放式鎖定，只有使用Update時才鎖定記錄）、adLockBatchOptimistic（開放式批更新）
Options：有adCmdText、adCmdTable、adCmdTableDirect和adCmdStoredProc等。
2）_variant_t vValue = m_pRs->Fields->Item[_variant_t(FieldName)]->Value;
_com_util::ConvertBSTRToString(_bstr_t(vValue));
m_pRs->Fields->Item[_variant_t(Field)]->Value = _variant_t(Value);
4、 通用數據命令模塊的實現
class CDBCommand
{
public:
//數據庫連接對象
CDBConnection * m_cnn;
//執行SQL
BOOL ExecuteSQL(CString SQL);
CDBCommand();
virtual ~CDBCommand();
};
CDBCommand::CDBCommand()
{
}
CDBCommand::~CDBCommand()
{
}
BOOL CDBCommand::ExecuteSQL(CString SQL)
{
ASSERT(m_cnn);
ASSERT(m_cnn->m_Actived);
try
{
m_cnn->m_pConn->Execute(_bstr_t(SQL), NULL, adCmdText);
return TRUE;
}
catch(_com_error &e)
{
return FALSE;
}
}
1）_RecordsetPtr Connection15::Execute ( _bstr_t CommandText, VARIANT * RecordsAffected, long Options )
CommandText：設置或返回包含提供者的命令。
RecordsAffected：可選，提供者向其返回操作所影響的記錄書目。
Options：有adCmdText、adCmdTable、adCmdTableDirect和adCmdStoredProc等。5、借用表命令類——CBorrowCommand（繼承了CDBCommand）
#include "DBCommand.h"
class CBorrowCommand : public CDBCommand
{
public:
//進行借用
//返回值為借用號
CString DoBorrow();
//各項借用信息
CString m_MaterialNum;
CString m_Count;
CString m_Department;
CString m_Use;
CString m_State;
CString m_Jsr;
CString m_Lqr;
CBorrowCommand();
virtual ~CBorrowCommand();
private:
//得到當前最大借用號
int GetMaxBorrowID();
};
CBorrowCommand::CBorrowCommand()
{
}
CBorrowCommand::~CBorrowCommand()
{
}
int CBorrowCommand::GetMaxBorrowID()
{
_RecordsetPtr pRs("ADODB.RecordSet");
pRs->Open(_variant_t("Select Max(ID) as MAXID From tblBorrow"), _variant_t(m_cnn->m_pConn, true), adOpenStatic, adLockOptimistic, adCmdText);
int nResult;
_variant_t vValue = pRs->Fields->Item[_variant_t("MAXID")]->Value;
//如果不為空，返回最大值；否則返回0
if (V_VT(&vValue) != VT_NULL)
{
nResult = atoi(_bstr_t(vValue));
}
else
{
nResult = 0;
}
pRs->Close();
return nResult;
}
CString CBorrowCommand::DoBorrow()
{
//得到當前時間
CString strData;
CTime time = CTime::GetCurrentTime();
strData.Format("%d-%d-%d %d:%d:%d",
time.GetYear(),
time.GetMonth(),
time.GetDay(),
time.GetHour(),
time.GetMinute(),
time.GetSecond());
CString strSQL;
//得到新的借用ID
int nMaxID = GetMaxBorrowID();
nMaxID++;
CString strNewID;
strNewID.Format("%d", nMaxID);
strSQL = "Insert into tblBorrow([ID], [MaterialNum], [Count], [Department], [Data], [Use], [State], [Jsr], [Lqr]) Values("
+ strNewID + ", "
+ m_MaterialNum + ", "
+ m_Count + ", \""
+ m_Department + "\", #"
+ strData + "#, \""
+ m_Use + "\", \""
+ m_State + "\", \""
+ m_Jsr + "\", \""
+ m_Lqr + "\")";
if(ExecuteSQL(strSQL))
{
return strNewID;
}
else
{
return "";
}
}
6、借用表訪問類——CBorrowDataSet（繼承了CDataSet）
#include "DataSet.h"
class CBorrowDataSet : public CDataSet
{
public:
CString GetID();
CString GetMaterialNum();
void SetCount(CString Value);
CString GetCount();
CString GetUse();
CString GetLqr();
CString GetState();
CString GetData();
CString GetDepartment();
CString GetJsr();
BOOL LoadDataByID(CString ID);
BOOL LoadData();
CBorrowDataSet();
virtual ~CBorrowDataSet();
};
CBorrowDataSet::CBorrowDataSet()
{
}
CBorrowDataSet::~CBorrowDataSet()
{
}
BOOL CBorrowDataSet::LoadData()
{
return Open("Select * From tblBorrow");
}
BOOL CBorrowDataSet::LoadDataByID(CString ID)
{
return Open("Select * From tblBorrow Where ID = " + ID);
}
CString CBorrowDataSet::GetCount()
{
return GetAsString("Count");
}
void CBorrowDataSet::SetCount(CString Value)
{
SetAsString("Count", Value);
}
CString CBorrowDataSet::GetMaterialNum()
{
return GetAsString("MaterialNum");
}
CString CBorrowDataSet::GetID()
{
return GetAsString("ID");
}
CString CBorrowDataSet::GetJsr()
{
return GetAsString("Jsr");
}
CString CBorrowDataSet::GetDepartment()
{
return GetAsString("Department");
}
CString CBorrowDataSet::GetData()
{
return GetAsString("Data");
}
CString CBorrowDataSet::GetState()
{
return GetAsString("State");
}
CString CBorrowDataSet::GetLqr()
{
return GetAsString("Lqr");
}
CString CBorrowDataSet::GetUse()
{
return GetAsString("Use");
}
7、用戶信息表訪問類——CUserInfoDataSet（繼承了CDataSet）
#include "DataSet.h"
class CUserInfoDataSet : public CDataSet
{
public:
//得到密碼
CString GetPassword();
//根據用戶名加載數據
BOOL LoadData(CString UserName);
CUserInfoDataSet();
virtual ~CUserInfoDataSet();
};
CUserInfoDataSet::CUserInfoDataSet()
{
}
CUserInfoDataSet::~CUserInfoDataSet()
{
}
BOOL CUserInfoDataSet::LoadData(CString UserName)
{
return Open("Select * From UserInfo Where Username like \"" + UserName + "\"");
}
CString CUserInfoDataSet::GetPassword()
{
return GetAsString("Password");
}
8、主程序的初始化
class CWhMgrApp : public CWinApp
{
public:
CDBConnection * m_pConn;
CWhMgrApp();
// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(CWhMgrApp)
public:
virtual BOOL InitInstance();
virtual int ExitInstance();
//}}AFX_VIRTUAL
// Implementation
//{{AFX_MSG(CWhMgrApp)
// NOTE - the ClassWizard will add and remove member functions here.
// DO NOT EDIT what you see in these blocks of generated code !
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
CWhMgrApp::CWhMgrApp()
{
// TODO: add construction code here,
// Place all significant initialization in InitInstance
}
/**//////////////////////////////////////////////////////////////////////////////// The one and only CWhMgrApp object
CWhMgrApp theApp;
/**//////////////////////////////////////////////////////////////////////////////// CWhMgrApp initialization
BOOL CWhMgrApp::InitInstance()
{
//初始化Com
::CoInitialize(NULL);
//初始化數據庫連接
m_pConn = new CDBConnection;
//得到當前程序所在的文件夾
CString strCommandLine = ::GetCommandLine();
int i;
int nLen = strCommandLine.GetLength();
for(i = nLen - 1; i >= 0; i--)
{
CHAR a = strCommandLine.GetAt(i);
if(a == '\\')
{
break;
}
}
strCommandLine.ReleaseBuffer(i + 1);
strCommandLine.Delete(0, 1);
//打開數據庫連接，數據庫地址為：當前程序所在文件夾\WhMgrDB.mdb
if(!m_pConn->Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strCommandLine + "WhMgrDB.mdb;Persist Security Info=False"))
{
::AfxMessageBox("打開數據庫失敗！");
return FALSE;
}
//用戶登錄
BOOL bLogined;
CLoginDlg loginDlg;
CUserInfoDataSet dsUserInfo;
dsUserInfo.m_cnn = m_pConn;
bLogined = FALSE;
//給3次登錄機會
for(i = 0; i < 3; i++)
{
if(loginDlg.DoModal() == IDOK)
{
dsUserInfo.LoadData(loginDlg.m_strUserName);
if(!dsUserInfo.IsEOF())
{
if(dsUserInfo.GetPassword() == loginDlg.m_strPassword)
{
bLogined = TRUE;
break;
}
}
else
{
::AfxMessageBox("用戶名或者密碼不正確，請重試！");
}
dsUserInfo.Close();
}
else
{
break;
}
}
if(!bLogined)
{
return FALSE;
}
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
CWhMgrDlg dlg;
//給dlg的m_pConn成員變量賦值
dlg.m_pConn = m_pConn;
m_pMainWnd = &dlg;
int nResponse = dlg.DoModal();
if (nResponse == IDOK)
{
// TODO: Place code here to handle when the dialog is
// dismissed with OK
}
else if (nResponse == IDCANCEL)
{
// TODO: Place code here to handle when the dialog is
// dismissed with Cancel
}
// Since the dialog has been closed, return FALSE so that we exit the
// application, rather than start the application's message pump.
return FALSE;
}
int CWhMgrApp::ExitInstance()
{
m_pConn->Close();
delete m_pConn;
::CoUninitialize();
return CWinApp::ExitInstance();
}
1 ）::CoInitialize(NULL);和::CoUninitialize();：ADO庫是一組COM動態庫，這意味應用程序在調用ADO前，必須初始化OLE/COM庫環境。在MFC應用程序里，一個比較好的方法是在應用程序主類的InitInstance成員函數里初始化OLE/COM庫環境。也可用
if(!AfxOleInit())//這就是初始化COM庫
{
AfxMessageBox(“OLE初始化出錯!”);
return FALSE;
}
2）得到當前程序所在的文件夾：
CString strCommandLine = ::GetCommandLine();
int i;
int nLen = strCommandLine.GetLength();
for(i = nLen - 1; i >= 0; i--)
{
CHAR a = strCommandLine.GetAt(i);
if(a == '\\')
{
break;
}
}
strCommandLine.ReleaseBuffer(i + 1);
strCommandLine.Delete(0, 1);
9、歸還的實現
class COutDialog : public CDialog
{
// Construction
public:
CDBConnection * m_pConn;
CString m_strMaterialNum;
COutDialog(CWnd* pParent = NULL); // standard constructor
// Dialog Data
//{{AFX_DATA(COutDialog)
enum { IDD = IDD_OUT_DIALOG };
CStatic m_Unit;
CComboBox m_MaterialNum;
BOOL m_bNeedReturn;
CString m_strCount;
CString m_strDepartment;
CString m_strJsr;
CString m_strLqr;
CString m_strState;
CString m_strUse;
//}}AFX_DATA
// Overrides
// ClassWizard generated virtual function overrides
//{{AFX_VIRTUAL(COutDialog)
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
//}}AFX_VIRTUAL
// Implementation
protected:
// Generated message map functions
//{{AFX_MSG(COutDialog)
virtual void OnOK();
afx_msg void OnSelchangeComboMaterialnum();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()
};
COutDialog::COutDialog(CWnd* pParent /**//*=NULL*/)
: CDialog(COutDialog::IDD, pParent)
{
//{{AFX_DATA_INIT(COutDialog)
m_bNeedReturn = FALSE;
m_strCount = _T("");
m_strDepartment = _T("");
m_strJsr = _T("");
m_strLqr = _T("");
m_strState = _T("");
m_strUse = _T("");
//}}AFX_DATA_INIT
}
void COutDialog::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
//{{AFX_DATA_MAP(COutDialog)
DDX_Control(pDX, IDC_STATIC_UNIT, m_Unit);
DDX_Control(pDX, IDC_COMBO_MATERIALNUM, m_MaterialNum);
DDX_Check(pDX, IDC_CHECK_NEEDRETURN, m_bNeedReturn);
DDX_Text(pDX, IDC_EDIT_COUNT, m_strCount);
DDX_Text(pDX, IDC_EDIT_DEPARTMENT, m_strDepartment);
DDX_Text(pDX, IDC_EDIT_JSR, m_strJsr);
DDX_Text(pDX, IDC_EDIT_LQR, m_strLqr);
DDX_Text(pDX, IDC_EDIT_STATE, m_strState);
DDX_Text(pDX, IDC_EDIT_USE, m_strUse);
//}}AFX_DATA_MAP
CMaterialInfoDataSet dsMaterialInfo;
dsMaterialInfo.m_cnn = m_pConn;
if(!dsMaterialInfo.LoadData())
{
::AfxMessageBox("加載物資信息失敗！");
}
else
{
while(!dsMaterialInfo.IsEOF())
{
m_MaterialNum.AddString(dsMaterialInfo.GetMaterialNum());
dsMaterialInfo.MoveNext();
}
dsMaterialInfo.Close();
}
if(m_MaterialNum.GetCount() > 0)
{
m_MaterialNum.SetCurSel(0);
OnSelchangeComboMaterialnum();
}
}
BEGIN_MESSAGE_MAP(COutDialog, CDialog)
//{{AFX_MSG_MAP(COutDialog)
ON_CBN_SELCHANGE(IDC_COMBO_MATERIALNUM, OnSelchangeComboMaterialnum)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()
/**//////////////////////////////////////////////////////////////////////////////// COutDialog message handlers
void COutDialog::OnOK()
{
int nIndex = m_MaterialNum.GetCurSel();
if(nIndex >= 0)
{
m_MaterialNum.GetLBText(nIndex, m_strMaterialNum);
}
else
{
m_strMaterialNum = "0";
}
CDialog::OnOK();
}
void COutDialog::OnSelchangeComboMaterialnum()
{
int nIndex = m_MaterialNum.GetCurSel();
if(nIndex >= 0)
{
CMaterialInfoDataSet dsMaterialInfo;
dsMaterialInfo.m_cnn = m_pConn;
CString strNum;
m_MaterialNum.GetLBText(nIndex, strNum);
dsMaterialInfo.LoadDataByNum(strNum);
if(!dsMaterialInfo.IsEOF())
{
m_Unit.SetWindowText(dsMaterialInfo.GetUnit());
}
dsMaterialInfo.Close();
}
}
1）給部分程序不僅給出了關于借出表的實現，還參有出庫的實現（關于出庫的出庫表命令類和出庫表訪問類這邊沒介紹，與借出表的差不多）。如有疑問可以聯系我。
這次利用一個工程中的一部分代碼對VC中ADO做了比較詳細的介紹，如有錯誤希望給與指正?。。。。。。。。。?br>
posted on 2009-06-18 22:58
The_Moment 閱讀(929)
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