C++ BUILDER 连ORACLE的麻烦,烦的很
ClientDataSet1->Close();
ClientDataSet1->CommandText="select max(seq) as maxseq from USERSURVEY where AGNO='"+AGNO+"' AND userid='"+userid+"'";
try{
ClientDataSet1->Open();
}
catch(Exception &e)
{
MessageBox(Handle,e.Message.c_str(),"数据库错误" ,MB_ICONWARNING+MB_OK);
return;
}
String seq;
if(ClientDataSet1->RecordCount==0)
return;
else
{
seq=ClientDataSet1->FieldByName("maxseq")->AsString;
}
执行到
seq=ClientDataSet1->FieldByName("maxseq")->AsString;时就报告错误,说什么超出范围,我只好改为了
ClientDataSet1->Close();
ClientDataSet1->CommandText="select seq from USERSURVEY where AGNO='"+AGNO+"' AND userid='"+userid+"' order by seq desc";
try{
ClientDataSet1->Open();
}
catch(Exception &e)
{
MessageBox(Handle,e.Message.c_str(),"数据库错误" ,MB_ICONWARNING+MB_OK);
return;
}
String seq;
if(ClientDataSet1->RecordCount==0)
return;
else
{
ClientDataSet1->First();
seq=ClientDataSet1->FieldByName("seq")->AsString;
}
这是怎么回事,问题出在哪