判断表是否存在.txt

来自「vc使用技巧汇集」· 文本 代码 · 共 47 行

如何判断一个access数据库中已经存在一个表table1?
STDMETHODIMP CADOTier::get_IsExistTable(BSTR bsTable, long lType, VARIANT_BOOL *pVal)
{
    ADODB::_RecordsetPtr  pRstSchema  = NULL;
    pRstSchema = m_connection->OpenSchema(ADODB::adSchemaTables);
    _bstr_t bsTableName(bsTable);
    _bstr_t table_name("");
    _bstr_t table_type("");
    char *pTemp1=NULL,*pTemp2=NULL;
    pTemp1 = _com_util::ConvertBSTRToString(bsTableName);
    pTemp1 = strlwr(pTemp1);
    VARIANT_BOOL b=FALSE;
    while(!(pRstSchema->adoEOF))
    {
        table_name = pRstSchema->Fields->
            GetItem("TABLE_NAME")->Value;
        pTemp2 = _com_util::ConvertBSTRToString(table_name);
        pTemp2 = strlwr(pTemp2);
        table_type = pRstSchema->Fields->
            GetItem("TABLE_TYPE")->Value;
        if (lType == 1) //view type
        {
            if (table_type == _bstr_t("VIEW"))
            {
                if (strcmp(pTemp1,pTemp2)==0)
                    b = TRUE;
            }
        }
        if (lType == 0) //table type
        {
            if (table_type == _bstr_t("TABLE"))
            {
                if (strcmp(pTemp1,pTemp2)==0)
                    b = TRUE;
            }
        }
        pRstSchema->MoveNext();
    }
    
    // Clean up objects before exit.
    if (pRstSchema)
        if (pRstSchema->State == ADODB::adStateOpen)
            pRstSchema->Close();
        *pVal = b;
        
        return S_OK;
}