OLEDB 静态绑定和数据转化接口

//静态绑定的结构
typedef struct _tag_DBSTRUCT
{
    DBSTATUS dbCodeStatus;
    ULONG uCodeLength;
    int nCode;

    DBSTATUS dbNameStatus;
    ULONG uNameLength;
    WCHAR szName[NAME_LENGTH];
}DBSTRUCT, *LPDBSTRUCT;

dbBindings[0].bPrecision = 0;
    dbBindings[0].bScale = 0;
    dbBindings[0].cbMaxLen = sizeof(int);
    dbBindings[0].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
    dbBindings[0].dwPart = DBPART_STATUS | DBPART_LENGTH | DBPART_VALUE;
    dbBindings[0].iOrdinal = pdbColumnInfo[0].iOrdinal;
    dbBindings[0].obStatus = offsetof(DBSTRUCT, dbCodeStatus);
    dbBindings[0].obLength = offsetof(DBSTRUCT, uCodeLength);
    dbBindings[0].obValue = offsetof(DBSTRUCT, nCode);
    dbBindings[0].wType = DBTYPE_I4;

    dbBindings[1].bPrecision = 0;
    dbBindings[1].bScale = 0;
    dbBindings[1].cbMaxLen = sizeof(WCHAR) * NAME_LENGTH;
    dbBindings[1].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
    dbBindings[1].dwPart = DBPART_STATUS | DBPART_LENGTH | DBPART_VALUE;
    dbBindings[1].iOrdinal = pdbColumnInfo[1].iOrdinal;
    dbBindings[1].obStatus = offsetof(DBSTRUCT, dbNameStatus);
    dbBindings[1].obLength = offsetof(DBSTRUCT, uNameLength);
    dbBindings[1].obValue = offsetof(DBSTRUCT, szName);
    dbBindings[1].wType = DBTYPE_WSTR;

    hRes = pIAccessor->CreateAccessor(DBACCESSOR_ROWDATA, 2, dbBindings, 0, &hAccessor, NULL);
    pdbStruct = (DBSTRUCT*)COM_ALLOC(sizeof(DBSTRUCT) * cRows);

    while (TRUE)
    {
        hRes = pIRowset->GetNextRows(DB_NULL_HCHAPTER, 0, cRows, &cRowsObtained, &prghRows);
        if (hRes != S_OK && cRowsObtained == 0)
        {
            break;
        }

        ZeroMemory(pdbStruct, sizeof(DBSTRUCT) * cRows);
        for (int i = 0; i < cRowsObtained; i++)
        {
            hRes = pIRowset->GetData(prghRows[i], hAccessor, &pdbStruct[i]);
            if (!FAILED(hRes))
            {
                COM_PRINTF(_T("%012d\t%s\n"), pdbStruct[i].nCode, pdbStruct[i].szName);
            }
        }

        pIRowset->ReleaseRows(cRowsObtained, prghRows, NULL, NULL, NULL);
    }