void OpenSchemaX(TCHAR *TableName)
{
HRESULT hr = S_OK;

::CoInitialize(NULL); //初始化Com

IADORecordBinding *picRs = NULL;

_RecordsetPtr pRstSchema("ADODB.Recordset");
_ConnectionPtr pConnection("ADODB.Connection" );

pConnection->ConnectionString = TableName;
pConnection->Provider = "Microsoft.Jet.OLEDB.4.0";

try
{
pConnection->Open(pConnection->ConnectionString, "", "", adModeUnknown);
pRstSchema->QueryInterface(
__uuidof(IADORecordBinding), (LPVOID*)&picRs);

pRstSchema = pConnection->OpenSchema(adSchemaTables);//枚举表的名称处理

while(!(pRstSchema->EndOfFile))
{
CString strTableType;

_bstr_t table_name = pRstSchema->Fields->
GetItem("TABLE_NAME")->Value;//获取表的名称

_bstr_t table_type = pRstSchema->Fields->
GetItem("TABLE_TYPE")->Value;//获取表的类型

strTableType.Format("%s",(LPCSTR) table_type);

if(!lstrcmp(strTableType,_T("TABLE")))
{
m_strList.AddString((LPCSTR) table_name);//添加表的名称
}

pRstSchema->MoveNext();
}
// Clean up objects before exit.

pRstSchema->Close();
pConnection->Close();
}

catch (_com_error &e)
{
// Notify the user of errors if any.
// Pass a connection pointer accessed from the Connection.
PrintProviderError(pConnection);
PrintComError(e);
}
CoUninitialize();
}

void PrintProviderError(_ConnectionPtr pConnection)
{
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);
CString strError;
strError.Format("Error number: %x\t%s", pErr->Number, pErr->Description);
AfxMessageBox(strError);
}
}
}

void PrintComError(_com_error &e)
{
_bstr_t bstrSource(e.Source());
_bstr_t bstrDescription(e.Description());

// Print COM errors.
CString strError;
strError.Format("Error number: Description = %s\tCode meaning = %s",(LPCSTR) bstrDescription, e.ErrorMessage());
AfxMessageBox(strError);
}

调用方法:

CString strFileName;
TCHAR FileName[MAX_PATH];
TCHAR bigBuff[2048] = _T(""); // maximum common dialog buffer size
TCHAR szFilter[] = _T("Text Files (*.mdb)|*.mdb|All Files (*.*)|*.*
");
CFileDialog dlg(TRUE, NULL, NULL,
OFN_HIDEREADONLY | OFN_ALLOWMULTISELECT, szFilter);

// Modify OPENFILENAME members directly to point to bigBuff
dlg.m_ofn.lpstrFile = bigBuff;
dlg.m_ofn.nMaxFile = sizeof(bigBuff);

if(IDOK == dlg.DoModal() )
{
strFileName = dlg.GetPathName();
lstrcpy(FileName,strFileName);
OpenSchemaX(FileName);
}(出处:风闪网路学院)
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!

RTX 5090要首发 性能要翻倍!三星展示GDDR7显存

三星在GTC上展示了专为下一代游戏GPU设计的GDDR7内存。

首次推出的GDDR7内存模块密度为16GB,每个模块容量为2GB。其速度预设为32 Gbps(PAM3),但也可以降至28 Gbps,以提高产量和初始阶段的整体性能和成本效益。

据三星表示,GDDR7内存的能效将提高20%,同时工作电压仅为1.1V,低于标准的1.2V。通过采用更新的封装材料和优化的电路设计,使得在高速运行时的发热量降低,GDDR7的热阻比GDDR6降低了70%。