ADO访问SQL（一）  

  

#import "C:Program FilesCommon FilesSystemadomsado15.dll"    no_namespace rename("EOF","rsEOF")
#include<iostream>

using namespace std;

//数据库基本操作类
class DataAccess
{
private:
    //申明数据库对象
    _ConnectionPtr pConn;
    _RecordsetPtr pRst;
    _CommandPtr pCmd;
    //连接标识符
    bool flag;
public:
    DataAccess()
    {
        //初始化连接对象
        CoInitialize(NULL);
        //创建ADO连接实例
        pConn.CreateInstance(__uuidof(Connection));
        //创建ADO记录集实例
        pRst.CreateInstance(__uuidof(Recordset));
        //创建ADO命令实例
        pCmd.CreateInstance(__uuidof(Command));
        //定义连接字符
        pConn->ConnectionString="Provider=SQLOLEDB;Server=(local);Database=Book; uid=sa; pwd=;";
        //标识符默认为false
        flag=false;
    }
    ~DataAccess()
    {
        //记录集不为空，释放记录集
        if(pRst!=NULL)
        {
            pRst->Close();
            pRst.Release();
        }
        //Cmd类不为空，释放Cmd
        if(pCmd!=NULL)
        {
            pCmd.Release();
        }
        //连接不为空，释放连接
        if(pConn!=NULL)
        {
            pConn->Close();
            pConn.Release();
        }
    }
    //打开数据库,成功返回TRUE,失败返回FALSE
    BOOL openConn()
    {
        try
        {
            this->pConn->Open("","","",adConnectUnspecified);
            flag=true;
            return flag;
        }
        catch(_com_error &e)
        {
            return FALSE;
        }
    }
    //执行SQL语句，成功返回_Recordset,失败返回NULL
    _RecordsetPtr searchSql(_bstr_t sql)
    {
        try
        {
            if(flag==false)
            {
                this->openConn();
            }
            pCmd->put_ActiveConnection(_variant_t((IDispatch*)pConn));
            pCmd->CommandText=sql;
            this->pRst->Open(sql,(IDispatch*)this->pConn,adOpenDynamic,adLockOptimistic,adCmdText);
            //this->pRst=pCmd->Execute(NULL,NULL,adCmdText);
            return pRst;
        }
        catch(_com_error &e)
        {
            return NULL;
        }
    }
};

 

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[收藏到我的网摘]   [发送Trackback]  kissyougoodby发表于 2007年09月14日 09:54:06