我的ADO连接SQL有问题，请帮忙

Question

我在stdafx.h中添加了：#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "adoEOF")然后在AppDlg.cpp的InitInstance()中使用连接：

                   _ConnectionPtr pConnection1 = NULL;

AfxEnableControlContainer();
AfxOleInit(); try
{

pConnection1->ConnectionString="Provider=SQLOLEDB.1
                            ;Persist Security Info=False;
                       User ID=sa;Initial Catalog=ADOtest;Data Source=CXL"
pConnection1->ConnectionTimeout=5;
pConnection1->Open("","","",adConnectUnspecified);
}
可是连语法编译都通不过，是不是我还少加了什么东西呢？根使用ADO连接数据库（sql server）一共有那些前期步骤？请告诉我，谢谢大家啊！
是不是COM没有初始化呢？那么应该怎么初始化呢？谢谢

Answer 1

// BeingConnectionStringCpp
#import "C:\Program Files\Common Files\System\ADO\msado15.dll" \
    no_namespace rename("EOF", "EndOfFile")#include <ole2.h>
#include <stdio.h>
#include <conio.h>// Function declarations
inline void TESTHR(HRESULT x) {if FAILED(x) _com_issue_error(x);};
void ConnectionStringX();
_bstr_t GetState(int intState); 
void PrintProviderError(_ConnectionPtr pConnection);
void PrintComError(_com_error &e);///////////////////////////////////////////////////////////
//                                                       //
//      Main Function                                    //
//                                                       //
///////////////////////////////////////////////////////////void main()
{
    if(FAILED(::CoInitialize(NULL)))
        return;    ConnectionStringX();    //Wait here for user to see the output..
    printf("\nPress any key to continue...");
    getch();    ::CoUninitialize();
}///////////////////////////////////////////////////////////
//                                                       //
//      ConnectionStringX Function                       //
//                                                       //
///////////////////////////////////////////////////////////void ConnectionStringX()
{
    // Define Connection object pointers.
    // Initialize pointers on define.
    // These are in the ADODB::  namespace
     _ConnectionPtr pConnection1 = NULL;
     _ConnectionPtr pConnection2 = NULL;
     _ConnectionPtr pConnection3 = NULL;
     _ConnectionPtr pConnection4 = NULL;    //Define Other Variables
    HRESULT  hr = S_OK;    try
    {
        // Open a connection using OLE DB syntax.
        TESTHR(pConnection1.CreateInstance(__uuidof(Connection)));
        pConnection1->ConnectionString = "provider=SQLOLEDB;" 
            "Data Source=MyServer;Initial Catalog=Pubs;"
          "User Id=sa;Password=;";
        pConnection1->ConnectionTimeout = 30;
        pConnection1->Open("","","",adConnectUnspecified);        // Open a connection using a DSN and ODBC tags.
        TESTHR(pConnection2.CreateInstance(__uuidof(Connection)));
        pConnection2->ConnectionString = "DSN=Pubs;UID=sa;PWD=;";
        pConnection2->Open("","","",adConnectUnspecified);        // Open a connection using a DSN and OLE DB tags.
        TESTHR(pConnection3.CreateInstance(__uuidof(Connection)));
        pConnection3->ConnectionString = "Data Source=Pubs;User ID=sa;"
            "Password=;";
        pConnection3->Open("","","",adConnectUnspecified);        // Open a connection using a DSN and individual
        // arguments instead of a connection string.
        TESTHR(pConnection4.CreateInstance(__uuidof(Connection)));
        pConnection4->Open("Pubs","sa","",adConnectUnspecified);        // Display the state of the connections.
        printf("cnn1 state: %s\n", 
            (LPCTSTR)GetState(pConnection1->State));
        printf("cnn2 state: %s\n", 
            (LPCTSTR)GetState(pConnection2->State));
        printf("cnn3 state: %s\n", 
            (LPCTSTR)GetState(pConnection3->State));
        printf("cnn4 state: %s\n", 
            (LPCTSTR)GetState(pConnection4->State));        //Cleanup objects before exit.
        pConnection4->Close();
        pConnection3->Close();
        pConnection2->Close();
        pConnection1->Close();
    }    catch(_com_error &e)
    {
        // Notify user of any errors.
        // Pass a connection pointer accessed from the Connection.
        PrintProviderError(pConnection1);
        if(pConnection2)
            PrintProviderError(pConnection2);
        if(pConnection3)
            PrintProviderError(pConnection3);
        if(pConnection4)
            PrintProviderError(pConnection4);
        PrintComError(e);
    }
}///////////////////////////////////////////////////////////
//                                                       //
//      GetState Function                                //
//                                                       //
///////////////////////////////////////////////////////////_bstr_t GetState(int intState) 
{
    _bstr_t strState; 
    switch(intState) 
    {
        case adStateClosed:
            strState = "adStateClosed";
            break;
        case adStateOpen:
            strState = "adStateOpen";
            break;
        default:
        ;
    }
    return strState;
}///////////////////////////////////////////////////////////
//                                                       //
//      PrintProviderError Function                      //
//                                                       //
///////////////////////////////////////////////////////////void PrintProviderError(_ConnectionPtr pConnection)
{
    // Print Provider Errors from Connection object.
    // pErr is a record object in the Connection's Error collection.
    ErrorPtr  pErr = NULL;    if( (pConnection->Errors->Count) > 0)
    {
        long nCount = pConnection->Errors->Count;        // Collection ranges from 0 to nCount -1.
        for(long i = 0; i < nCount; i++)
        {
            pErr = pConnection->Errors->GetItem(i);
            printf("Error number: %x\t%s\n", pErr->Number, 
                (LPCSTR)pErr->Description);
        }
    }
}///////////////////////////////////////////////////////////
//                                                       //
//      PrintComError Function                           //
//                                                       //
///////////////////////////////////////////////////////////void PrintComError(_com_error &e)
{
    _bstr_t bstrSource(e.Source());
    _bstr_t bstrDescription(e.Description());    // Print Com errors.  
    printf("Error\n");
    printf("\tCode = %08lx\n", e.Error());
    printf("\tCode meaning = %s\n", e.ErrorMessage());
    printf("\tSource = %s\n", (LPCSTR) bstrSource);
    printf("\tDescription = %s\n", (LPCSTR) bstrDescription);
}
// EndConnectionStringCpp

Answer 2

啊，这不是COPY的MSDN的吗：（

Answer 3

是不是少了这两句实例化的代码：
MyDb.CreateInstance("ADODB.Connection");
MySet.CreateInstance("ADODB.Recordset");
在initinstance中还要加上初始化com环境的：
::CoInitialize(NULL);
不然有可能连接过程中出现“无效指针”的问题。
为什么不说清楚你的错误信息是什么呢？

Answer 4

MyDb.CreateInstance("ADODB.Connection");
MySet.CreateInstance("ADODB.Recordset");这两句不可少！::CoInitialize(NULL);//这一句可以不要！www.vccode.com第十期上有几篇文章，建议看看！

Answer 5

我是这么用的,需要在ODBC设置数据源
BOOL CXXXApp::InitInstance()
{
AfxEnableControlContainer(); AfxOleInit();
try
{   m_pConnection.CreateInstance(__uuidof(Connection));
m_pConnection->ConnectionTimeout = 8;
//SQL SERVER
    // m_pConnection->Open("Driver=SQL Server;Database=stufilemanage;Server=127.0.0.1;UID=sa;PWD=;","","",adModeUnknown);
}
catch(_com_error e)///捕捉异常
{
AfxMessageBox("连接数据库失败!");
return FALSE;
} 
....
}