vc 用ado访问Oracle数据库的代码示例

先决条件

1.客户端一定要安装 Oracle的oledb的驱动。可到以下网址下载(10.版本的大概190M)

http://otn.oracle.com/software/tech/windows/ole_db/content.html

2.要使用Net Configuration Assistant配置好侦听及相关环境

代码

首先，在 stdafx.h 中加入以下代码，导入ado库

#import "c:\program files\common files\system\ado\msado15.dll" no_namespace rename ("EOF", "adoEOF")

其次，要确保有 ::CoInitialize(NULL)的调用，以初始化COM.

//类定义

class CDBOp
{
public:
bool ReConnect();

bool CloseConnect();
bool OpenConnect(int dbType, CString hostName, CString dBName, CString userName, CString password);

bool GetItemData(CString itemID, float &price, CString &descript); //取存储过程数据，这里只是举例说明
CString GetErrorMsg();
CDBOp();
virtual ~CDBOp();

private:
_ConnectionPtr m_pConnection; //连接对象
_RecordsetPtr m_pRecordset; //记录集对象

bool   m_bConnectSuccess;     //连接是否成功
CString   m_strConnString;      //数据库连接字符串
CString   m_strErrMsg;           //保存错误信息
};

//类实现

CDBOp::CDBOp():m_bConnectSuccess(false)
{
::CoInitialize(NULL);

m_pConnection.CreateInstance("ADODB.Connection");
m_pConnection->ConnectionTimeout=30;
m_pRecordset.CreateInstance("ADODB.Recordset");
}

CDBOp::~CDBOp()
{
//::CoUninitialize();
CloseConnect();
}

//打开连接(数据库类型，主机名，数据库名，登陆名，密码)
//数据库类型: 0 为Sql server, 1为 Oracle
bool CDBOp::OpenConnect(int dBType,
        CString hostName,
        CString dBName,
        CString userName,
        CString password)
{
CString strConn;

if (dBType =0)  //Sql server
{
  strConn = "Provider=SQLOLEDB.1";
  strConn+= ";User ID=";
  strConn+= userName;
  strConn+= ";Password=";
  strConn+= password;
  strConn+= ";Initial Catalog=";
  strConn+= dBName;
  strConn+= ";Data Source=";
  strConn+= hostName;
}
else if (dBType =1) //Oracle
{
//MSDAORA or OraOLEDB.Oracle.1
  strConn = "Provider=OraOLEDB.Oracle.1";
  strConn+= ";Persist Security Info=true";
  strConn+= ";User ID=";
  strConn+= userName;
  strConn+= ";Password=";
  strConn+= password;

  strConn+= ";Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)";
  strConn+= "(HOST=";
  strConn+= hostName;
  strConn+= ")(PORT=1521))(CONNECT_DATA=";
  strConn+= "(SERVICE_NAME=";
  strConn+= dBName;
  strConn+= ")))";
}

if (strConn.IsEmpty())
{
  m_strErrMsg="The connect string is null.";
  return false;
}

CloseConnect();

m_strConnString =strConn;

return ReConnect();
}

//再次连接
bool CDBOp::ReConnect()
{
m_strErrMsg=_T("");
m_bConnectSuccess= false;

HRESULT hr;
try
{
  hr = m_pConnection->Open(_bstr_t(m_strConnString), "", "", adModeUnknown);
  if (SUCCEEDED(hr))
   m_bConnectSuccess=true;
}
catch(_com_error e)
{
  m_strErrMsg.Format("Connect database failure!\r\n\r\n message error:%s\r\n\r\n The connect string:%s",e.ErrorMessage(),m_strConnString);
}

return m_bConnectSuccess;
}

//关闭链接
bool CDBOp::CloseConnect()
{
if (m_bConnectSuccess)
{
if (m_pConnection->State==1)
m_pConnection->Close();

m_bConnectSuccess =false;
}
return true;
}

//取得错误信息
CString CDBOp::GetErrorMsg()
{
return m_strErrMsg;
}

bool CDBOp::GetItemData(CString itemID, float &price, CString &descript)

{
_CommandPtr   pCommand = NULL;
pCommand.CreateInstance("ADODB.Command");
    #ifdef   _DEBUG
    if   (pCommand   ==   NULL)
    {
      AfxMessageBox("Command Created fail! Please confirm whether initialize COM.");
    }
    #endif
    ASSERT(pCommand   !=   NULL);

    try
    {
  if (m_bConnectSuccess==false)
  {
   if (ReConnect()==false)
    return false;
  }

  //输入参数   itemID
  _ParameterPtr   pParamItemID;
  pParamItemID.CreateInstance("ADODB.Parameter");
  pParamItemID->Name="ItemID";   //所用存储过程参数名称
  pParamItemID->Type=adChar;    //参数类型
  pParamItemID->Size=10;     //参数大小
  pParamItemID->Direction=adParamInput;  //表明是输入参数
  pParamItemID->Value=_variant_t(itemID);
  pCommand->Parameters->Append(pParamItemID);


  //输出参数   price
  _ParameterPtr   pParamPrice;
  pParamPrice.CreateInstance("ADODB.Parameter");
  pParamPrice->Name="Price";    //参数名称
  pParamPrice->Type=adNumeric;    //参数类型
  pParamPrice->Size=9;      //参数大小
  pParamPrice->Precision =9;
  pParamPrice->NumericScale =2;

pParamPrice->Direction=adParamOutput; //声明是输出参数
pCommand->Parameters->Append(pParamPrice);

  //输出参数   Descript
  _ParameterPtr   pParamDescript;
  pParamDescript.CreateInstance("ADODB.Parameter");
  pParamDescript->Name="Descript";   //参数名称
  pParamDescript->Type=adVarChar;    //参数类型
  pParamDescript->Size=160;     //参数大小
  pParamDescript->Direction=adParamOutput; //声明是输出参数
  pCommand->Parameters->Append(pParamDescript);

  //执行存储过程
  pCommand->ActiveConnection=m_pConnection;
  pCommand->CommandText="spItemInfo";   //存储过程名称
  pCommand->CommandType=adCmdStoredProc;  //表示为存储过程adCmdStoredProc
  pCommand->Execute(NULL,   NULL,   adCmdStoredProc);


  price=(float)(pParamPrice->Value);
  descript = (char*)_bstr_t(pParamDescript->Value);

  return true;
}
    catch(_com_error   e)
    {
      m_strErrMsg.Format(_T("Error:GetItemData. Reason:%s\n file: %s; line: %d\n"), e.ErrorMessage(), __FILE__, __LINE__);
   return false;
    }

}

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vc 用ado访问Oracle数据库的代码示例

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