🚀 go-pugleaf

I want to update a blob field in my table of MS Sql Server database. I use
code below, but it isn't work and report a exception:String or binary data
would be truncated. What can I do?

void __fastcall Tfrm::buttonUploadClick(TObject *Sender)
{
    ADOConnection1->Connected=true;
    ADOTable1->Active=true;
    ProgressBar1->Max=ADOTable1->RecordCount;
    ProgressBar1->Position=0;
    ADOTable1->First();
    while(!ADOTable1->Eof){

        Application->HandleMessage();


        if(Trim(ADOTable1->FieldByName("download_URL")->AsString)!="")
        {

            String strSql = "update papers set pdf=:pdf where id=" ;
            strSql+=ADOTable1->FieldByName("id")->AsString  ;

            ADOQuery1->Close();
            ADOQuery1->Parameters->Clear();
            ADOQuery1->SQL->Clear();
            ADOQuery1->SQL->Add(strSql);

ADOQuery1->Parameters->ParamByName("pdf")->LoadFromFile(editFolder->Text+"\\
"+ADOTable1->FieldByName("download_URL")->AsString, ftBlob);
            ADOQuery1->ExecSQL();


        }
        ProgressBar1->Position+=1;
        ADOTable1->Next();
    }

    ShowMessage("���");
}