VC?ADO?????????? ZT

wxhwhmanshan

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??ADO??
ADO?Microsoft?????????????? OLE DB ?????????????????????ADO ????????????? OLE. DB ???????????????????ADO ????????????????????????????ADO ??????????????????????????????????????????????????????????????? ADO??????????????OLE ??????

OLE DB???�??????�(COM) ??????????????????ODBC??????????????????????????OLE DB?Microsoft UDA(Universal Data Access)????????OLE DB ????????????????????????????????????????????????????????????????OLE DB ????? ISAM?Jet ?????????????????????????????????????????????????????????? Excel ???????????????/?????????????? Microsoft Exchange ????????OLE DB ???????????????????????????????????????????API ????????????OLE DB ??????? ActiveX Data Objects (ADO)?

???VC???ADO(???????)

1???ADO???

??ADO???????stdafx.h???????????#import??ADO???,??????????????????

?#import??ADO???

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

????????????ADO?????ADO????????????????????EOF???adoEOF???????????????????ADO????

2????OLE/COM???
???????ADO????COM??????????????ADO???????OLE/COM?????MFC???????????????????????InitInstance????????OLE/COM????

BOOL CMyAdoTestApp??InitInstance()
{
if(!AfxOleInit())//??????COM?
{
AfxMessageBox(�OLE?????!�);
return FALSE;
}

��

}

3?ADO????

ADO?????????:_ConnectionPtr???_CommandPtr???_RecordsetPtr???
_ConnectionPtr???????????????????????????????????????????SQL?????????????_ConnectionPtr?????????????????????????????????_RecordserPtr??????_ConnectionPtr?????????????????????_RecordserPtr?????

_CommandPtr???????????????????????????????????SQL??????_CommandPtr???????????_ConnectionPtr???????_CommandPtr????????????????????????????????????????????????????????????????????????_ConnectionPtr???????????????_CommandPtr?????????SQL???

_RecordsetPtr????????????????????????????????????????????????_CommandPtr????????????????????????????????????????_RecordsetPtr?connection???????????????????????????????????Command??????????????????_ConnectionPtr??
?????_RecordsetPtr???????SQL????

4???_ConnectionPtr??
_ConnectionPtr???????????????????????????????????????????ODBC?DSN???
  _ConnectionPtr pConn;
if (FAILED(pConn.CreateInstance("ADODB.Connection")))
{
AfxMessageBox("Create Instance failed!");
return;
}


CString strSRC;
strSRC="Driver=SQL Server;Server=";
strSRC+="suppersoft";
strSRC+=";Database=";
strSRC+="mydb";
strSRC+=";UID=SAWD=";

CString strSQL = "Insert into student(no,name,sex,address) values(3,'aaa','male','beijing')";

_variant_t varSRC(strSRC);
_variant_t varSQL(strSQL);
_bstr_t bstrSRC(strSRC);

if (FAILED(pConn->Open(bstrSRC,"","",-1)))
{
AfxMessageBox("Can not open Database!");
pConn.Release();
return;
}

COleVariant vtOptional((long)DISP_E_PARAMNOTFOUND,VT_ERROR);

pConn->Execute(_bstr_t(strSQL),&vtOptional,-1);

pConn.Release();

AfxMessageBox("ok!");

5???_RecordsetPtr??(???SQL Server??)
_RecordsetPtr pPtr;
if (FAILED(pPtr.CreateInstance("ADODB.Recordset")))
{
AfxMessageBox("Create Instance failed!");
return FALSE;
}

CString strSRC;
strSRC="Driver=SQL Server;Server=";
strSRC+="210.46.141.145";
strSRC+=";Database=";
strSRC+="mydb";
strSRC+=";UID=sa;PWD=";
strSRC+="sa";

CString strSQL = "select id,name,gender,address from personal";

_variant_t varSRC(strSRC);
_variant_t varSQL(strSQL);

if(FAILED(pPtr->Open(varSQL,varSRC,adOpenStatic,adLockOptimistic,adCmdText)))
{
AfxMessageBox("Open table failed!");
pPtr.Release();
return FALSE;
}

while(!pPtr->GetadoEOF())
{
_variant_t varNo;
_variant_t varName;
_variant_t varSex;
_variant_t varAddress;

varNo = pPtr->GetCollect ("id");
varName = pPtr->GetCollect ("name");
varSex = pPtr->GetCollect ("gender");
varAddress = pPtr->GetCollect ("address");

CString strNo =(char *)_bstr_t(varNo);
CString strName =(char *)_bstr_t(varName);
CString strSex =(char *)_bstr_t(varSex);
CString strAddress =(char *)_bstr_t(varAddress);

strNo.TrimRight();
strName.TrimRight();
strSex.TrimRight();
strAddress.TrimRight();

int nCount = m_list.GetItemCount();
int nItem = m_list.InsertItem (nCount,_T(""));
m_list.SetItemText (nItem,0,strNo);
m_list.SetItemText (nItem,1,strName);
m_list.SetItemText (nItem,2,strSex);
m_list.SetItemText (nItem,3,strAddress);

pPtr->MoveNext();
}

pPtr->Close();
pPtr.Release();

6???_CommandPtr??
_CommandPtr??????Recordset????????????????????????????_CommandPtr??????

??11:??_CommandPtr??????
_CommandPtr pCommand;
_RecordsetPtr pRs;
pCommand.CreateInstance(__uuidof(Command));
pCommand->ActiveConnection=pConn;
pCommand->CommandText="select * from student";
pCommand->CommandType=adCmdText;
pCommand->Parameters->Refresh();
pRs=pCommand->Execute(NULL,NULL,adCmdUnknown);
_variant_t varValue = pRs->GetCollect("name");
Cstring strValue=(char*)_bstr_t(varValue);

6???????????COM??????????????????????????????
??Cstring ??COM??????????????API???COM???C++??????_vatiant_t?_bstr_t?????????????????????COM???C++??????


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