NULL空值的问题
lwfqt 2007-05-28 03:33:02 strSQL="select top 1 ID from jiance where dengluzhuangtai=0 order by ID ";
ADOQuery1->Close();
ADOQuery1->SQL->Clear();
ADOQuery1->SQL->Add(strSQL);
ADOQuery1->Open();
strID=ADOQuery1->FieldByName("ID")->AsString;
if(strID!=NULL)
{
strSQL="UPDATE jiance set denglu=1,dengluzhuangtai=1 where ID="+strID;
ADOQuery1->Close();
ADOQuery1->SQL->Add(strSQL);
ADOQuery1->ExecSQL();
strID="2_"+strID;
intConecout=ServerSocket1->Socket->ActiveConnections;//取得客户端连接的数目
for(int i=0;i<intConecout;i++)
{
strCliIP=ServerSocket1->Socket->Connections[i]->RemoteAddress;
if(strCliIP==strClientIP)//IP地址相等时就发送
{
ServerSocket1->Socket->Connections[i]->SendText(strID);
}
}
}
else
{ ShowMessage("无数据!"); }
这段程序中,strID已经为NULL,但执行到if(strID!=NULL)的时候,缺跳到了strSQL="UPDATE jiance set denglu=1,dengluzhuangtai=1 where ID="+strID;
而不是ShowMessage,怎么会这样?