网上关于ADO的使用方法很多，这边我个人就整理出一个使用ADO的方法的具体步骤：
1、用#import引入ADO库文件
在stdafx.h文件中添加#import "c:\program files\common files\system\ado\msado15.dll"no_namespaces rename("EOF" adoEOF")
2、 数据库连接，创建CDBConnection，代码如下：
 class CDBConnection
   {
 public:
//数据库是否已连接
BOOL m_Actived;
//关闭连接
void Close();
//打开连接
BOOL Open(CString CnnStr);
//ADO的连接对象指针
_ConnectionPtr m_pConn;
CDBConnection();
virtual ~CDBConnection();
 };
CDBConnection::CDBConnection()
{
//创建连接对象
m_pConn.CreateInstance("ADODB.Connection");
m_Actived = FALSE;
}
CDBConnection::~CDBConnection()
{
//释放连接对象
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;
}
}
相关函数：
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
为数据库的地址，WhMgrDB.mdb为所要用到的数据库。
UserID和Password分别为建立连接时所使用的用户名和密码
Options：
决定是使用同步方式（adConnectUnspecified默认）还是异步方式（adAsyncConnext）打开数据库。当使用同步方式打开数据
库时，只有打开完成，Open方法才返回；而是用异步方式打开数据库时，Open方法在建立连接完成之前就返回。
3、 通用数据访问模块的实现
class CDataSet
{
protected:
//打开查询
BOOL Open(CString SQL);
public:
//删除当前记录
void Delete();
//更新记录
void Update();
//将Field列的值设置为Value
void SetAsString(CString Field, CString Value);
//关闭查询
void Close();
//加载数据
virtual BOOL LoadData();
//得到Field列的值
CString GetAsString(CString FieldName);
//是否在第一条记录之前
BOOL IsBOF();
//是否在最后一条记录之后
BOOL IsEOF();
//移动到上一条记录
void MovePrevious();
//移动到下一条记录
void MoveNext();
//移动到最后一条记录
void MoveLast();
//移动到第一条记录
void MoveFirst();
//数据库连接对象
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;
//如果为空值则返回空
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);
}
相关函数：
1）HRESULT Recordset15::Open (
const _variant_t & Source, const _variant_t & ActiveConnection,
enum CursorTypeEnum CursorType, enum LockTypeEnum LockType, long Options
)
Source:变体型，计算Command对象的变量名、SQL语句、表名、存储过程调用或持久Recordset文件名。
ActiveConnection：计算有效地Connection对象变量名或字符串，包含ConnectionString参数。
CursorType：确定提供者打开Recordset时应该使用的游标类型。
LockType：adLockReadOnly（默
认值，只读）、adLockPessimistic（保守式锁定）、adLockOptimistic（开放式锁定，只有使用Update时才锁定记
录）、adLockBatchOptimistic（开放式批更新）
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、 通用数据命令模块的实现
class CDBCommand
{
public:
//数据库连接对象
CDBConnection * m_cnn;
//执行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：设置或返回包含提供者的命令。
RecordsAffected：可选，提供者向其返回操作所影响的记录书目。
Options：有adCmdText、adCmdTable、adCmdTableDirect和adCmdStoredProc等。5、借用表命令类——CBorrowCommand（继承了CDBCommand）
#include "DBCommand.h"
class CBorrowCommand : public CDBCommand
{
public:
//进行借用
//返回值为借用号
CString DoBorrow();
//各项借用信息
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:
//得到当前最大借用号
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;
//如果不为空，返回最大值；否则返回0
if (V_VT(&vValue) != VT_NULL)
{
nResult = atoi(_bstr_t(vValue));
}
else
{
nResult = 0;
}
pRs->Close();
return nResult;
}
CString CBorrowCommand::DoBorrow()
{
//得到当前时间
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、借用表访问类——CBorrowDataSet（继承了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、用户信息表访问类——CUserInfoDataSet（继承了CDataSet）
#include "DataSet.h"
class CUserInfoDataSet : public CDataSet
{
public:
//得到密码
CString GetPassword();
//根据用户名加载数据
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);
//初始化数据库连接
m_pConn = new CDBConnection;
//得到当前程序所在的文件夹
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);
//打开数据库连接，数据库地址为：当前程序所在文件夹\WhMgrDB.mdb
if(!m_pConn->Open("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strCommandLine + "WhMgrDB.mdb;Persist Security Info=False"))
{
::AfxMessageBox("打开数据库失败！");
return FALSE;
}
//用户登录
BOOL bLogined;
CLoginDlg loginDlg;
CUserInfoDataSet dsUserInfo;
dsUserInfo.m_cnn = m_pConn;
bLogined = FALSE;
//给3次登录机会
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("用户名或者密码不正确，请重试！");
}
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;
//给dlg的m_pConn成员变量赋值
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库是一组COM动态库，这意味应用程序在调用ADO前，必须初始化OLE/COM库环境。在MFC应用程序里，一个比较好的方法是在应用程序主类的InitInstance成员函数里初始化OLE/COM库环境。也可用
if(!AfxOleInit())//这就是初始化COM库
{
AfxMessageBox(“OLE初始化出错!”);
return FALSE;
}
2）得到当前程序所在的文件夹：
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、归还的实现
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("加载物资信息失败！");
}
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）给部分程序不仅给出了关于借出表的实现，还参有出库的实现（关于出库的出库表命令类和出库表访问类这边没介绍，与借出表的差不多）。如有疑问可以联系我。
这次利用一个工程中的一部分代码对VC中ADO做了比较详细的介绍，如有错误希望给与指正！！！！！！！！！！
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