MySQL使用connector C/C+读取二进制字段，两种方法：

用getString

vector<char> vec;
  while (pResultSet->next())
  {
  	string str = pResultSet->getString("data");
  	vec.insert(vec.end(), str.begin(), str.end());
  }

 vector<char> vecALL;
  while (pResultSet->next())
  {
  	istream *pis= pResultSet->getBlob("data");
  	pis->seekg(0, ios::end);
  	int sz = pis->tellg();
  	pis->seekg(ios::beg);
  	vector<char> vecTemp;
  	vecTemp.resize(sz);
  	pis->read(&vecTemp[0], sz);
  	vecALL.insert(vecALL.end(), vecTemp.begin(),vecTemp.end());
  }