Ошибка при выборке таблицы (invalid object name 'table')

ADOQuery2.Close;ADOQuery2.SQL.Clear;
        ADOQuery2.SQL.Add('select Fio,pass_t,n_doc from database_kli,amfot where database_kli.n_doc=amfot.pass_t');
        ADOQuery2.open;

ADOQuery2.Close;ADOQuery2.SQL.Clear;
ADOQuery2.SQL.Add('select Fio,pass_t,n_doc from database_kli,amfot where database_kli.n_doc=amfot.pass_t');
ADOQuery2.open;

ADOQuery1.Close; ADOQuery1.sql.Clear;
        ADOQuery1.SQL.Add('select * from database_kli where n_doc>0');
        ADOQuery1.open;
 
        ADOQuery3.Close; ADOQuery3.sql.Clear;
        ADOQuery3.sql.Add('select * from amfot');
        ADOQuery3.open;
 
         while not ADOQuery1.Eof do
        begin
        if ADOQuery1.Fields.fieldbyname('n_doc').AsString=ADOQuery3.Fields.Fieldbyname('pass_t').AsString then
        ADOQuery2.Close;ADOQuery2.SQL.Clear;
        ADOQuery2.SQL.Add('select database_kli.Fio,amfot.pass_t,database_kli.n_doc from database_kli   join amfot on database_kli.n_doc=amfot.pass_t');
        ADOQuery2.open;
        ADOQuery1.Next;
        end;

if ADOQuery1.Fields.fieldbyname('n_doc').AsString
=ADOQuery3.Fields.Fieldbyname('pass_t').AsString then
  ADOQuery2.Close;ADOQuery2.SQL.Clear;