Sql server 为什么OLE DB IRowset.GetNextRows访问冲突

我正在使用OLE DB从SQL server检索一些数据，代码的概要如下

m_spCmd->SetCommandText(DBGUID_DEFAULT,L"SELECT * FROM sys.DM_OS_PERFORMANCE_COUNTERS"); // S_OK
CComPtr<IRowset> result;
m_spCmd->Execute(nullptr,__uuidof(IRowset),nullptr,nullptr,(IUnknown**)&result); // S_OK
DBCOUNTITEM fetched;
HROW *hrow;
result->GetNextRows(DB_NULL_HCHAPTER,0,1,&fetched,&hrow);  // A

sqlcmd.cpp

编撰

跑

字体这样说

如果*prghRows不是输入上的空指针，则它必须是指向的指针 使用者分配的内存足够大，可以返回 请求的行数。如果使用者分配的内存较大 如果不需要，则提供程序将按照 pcrowsobained；剩余内存的内容未定义

所以不能在输入上传递随机指针。必须将其设置为有效或空值：

HROW* hrow = NULL;

---

你有完整的小型复制代码吗？上传代码供审查：）

#include "sqlcmd.h"

template<> 
void SQLCmd::print(CComPtr<IRowset> ptr)
{
  DBORDINAL count;
  DBCOLUMNINFO *info;
  OLECHAR *buf;
  
  auto accessor = CComQIPtr<IAccessor>(ptr);
  auto colinfo = CComQIPtr<IColumnsInfo>(ptr);
  colinfo->GetColumnInfo(&count,&info,&buf);
  
  /*
  DBBINDING *bindings = new DBBINDING[count];
  memset(bindings,0,sizeof(DBBINDING)*count);

  DBBINDSTATUS *bindingstatus = new DBBINDSTATUS[count];
  memset(bindingstatus,0,sizeof(DBBINDSTATUS)*count);
  
  DBBYTEOFFSET offset = 0;
  int rowsize = 0;
  for(int i = 0 ; i < count ; i++)
  {
    auto &[pwszName,pTypeInfo,iOrdinal,dwFlags,ulColumnSize,wType,bPrecision,bScale,columnid] = info[i];
    bindings[i].iOrdinal = iOrdinal;
    bindings[i].obValue = offset;
    bindings[i].wType = wType;
    bindings[i].dwPart = DBPART_VALUE;
    bindings[i].bPrecision = bPrecision;
    bindings[i].bScale = bScale;
    offset += ulColumnSize;
    rowsize += ulColumnSize;
    printf("%ws %lld %d\n",pwszName,ulColumnSize,wType);
  }
  
  HACCESSOR haccessor;
  hr = accessor->CreateAccessor(DBACCESSOR_ROWDATA,count,bindings,rowsize,&haccessor,bindingstatus);
  printf("CreateAccessor %x %llx\n",hr,haccessor);
  for(int i = 0 ; i < count ; i++)
    if(DBBINDSTATUS_OK != bindingstatus[i])
      printf("%d - %d\n",i,bindingstatus[i]);*/
  
  DBCOUNTITEM fetched;
  HROW *hrow;
  printf("before GetNextRows\n");
  hr = ptr->GetNextRows(DB_NULL_HCHAPTER,0,1,&fetched,&hrow);  
  printf("GetNextRows %x %lld\n",hr,fetched);
}

SQLCmd::SQLCmd()
{
  GUID msoledbsql;
  CLSIDFromString(L"{5A23DE84-1D7B-4A16-8DED-B29C09CB648D}",&msoledbsql);
  m_spDb.CoCreateInstance(msoledbsql);
  
  m_spDbProperty = CComQIPtr<IDBProperties>(m_spDb);
  CDBPropSet set(DBPROPSET_DBINIT);
  set.AddProperty(DBPROP_AUTH_INTEGRATED,L"SSPI");
  set.AddProperty(DBPROP_INIT_CATALOG,L"master");
  set.AddProperty(DBPROP_INIT_DATASOURCE,L"localhost");
  m_spDbProperty->SetProperties(1,&set);
  
  m_spDb->Initialize();

  auto m_spCrsession = CComQIPtr<IDBCreateSession>(m_spDb);
  if (!!m_spCrsession)
  {
    hr = m_spCrsession->CreateSession(nullptr,__uuidof(ISessionProperties),(IUnknown**)&m_spSsProperty);
    auto _ = CComQIPtr<IDBCreateCommand>(m_spSsProperty);
    if (!!_)
      hr = _->CreateCommand(nullptr,__uuidof(ICommandText),(IUnknown**)&m_spCmd);      
  }
  
  CComPtr<IRowset> result;
  hr = m_spCmd->SetCommandText(DBGUID_DEFAULT,L"SELECT * FROM sys.DM_OS_PERFORMANCE_COUNTERS");
  printf("SetCommandText 0x%x\n",hr);
  DBROWCOUNT rowcount;
  hr = m_spCmd->Execute(nullptr,__uuidof(IRowset),nullptr,&rowcount,(IUnknown**)&result);
  printf("Execute 0x%x %lld\n",hr,rowcount);
  if (!!result)
  {
    print(result);
  } 
}

SQLCmd::~SQLCmd()
{
  if (!!m_spDb) m_spDb->Uninitialize();
}

#include "sqlcmd.h"
int main()
{
  CoInitialize(nullptr);
  SQLCmd cmd;
}

cl /nologo /EHsc /std:c++latest test.cpp sqlcmd.cpp /link /debug

>test
SetCommandText 0x0
Execute 0x0 -1
before GetNextRows

HROW* hrow = NULL;