Comment supprimer les doubles entrées dans les champs ?

     procedure TForm1.Button28Click(Sender: TObject);
     var
        pdfs: string;
     begin
        UniConnection1.Loginprompt:=true;
        UniScript_cr_linknames.Execute;
        uniquery8.Execute;

        uniquery9.sql.text:='Select * from refs order by id asc;';
        uniquery9.execute;
        while not(uniquery9.eof) do
           begin
           uniquery11.sql.text:='Select * from linknames where id = :vonid group by linkname order by linkname; ';
           uniquery11.parambyname('vonid').asinteger:=uniquery9.fieldbyname('id').asinteger;
           uniquery11.execute;
           pdfs:='';
           while not(uniquery11.eof) do
              begin
              if pdfs='' then
                 pdfs:=uniquery11.fieldbyname('linkname').asstring
              else
                 pdfs:=pdfs+#13#10+   uniquery11.fieldbyname('linkname').asstring;

              //if uniquery11.RecordCount > 1 then ShowMessage(format('Update refs set link_to_pdf = %s where id=%d;',[pdfs,uniquery9.fieldbyname('id').asinteger]));

              uniquery11.Next;   
              end;

           uniquery10.sql.text:='Update refs set link_to_pdf = :links where id=:vonid;';
           uniquery10.parambyname('links').asstring:=pdfs;
           uniquery10.parambyname('vonid').asinteger:=uniquery9.fieldbyname('id').asinteger;
           uniquery10.execute;
           if Pos(#13,pdfs)> 0 then WriteLOgMemo(Format('UPD: Id: %d done with more than one unique-LINK ) :',[uniquery9.fieldbyname('id').asinteger]));

           uniquery9.next;
           end;

           end;

alors que la Query8 et le script ressemblent à ceci :

     insert into linknames (id,linkname)
     (SELECT
       refs.id,
       SUBSTRING_INDEX(SUBSTRING_INDEX(refs.link_to_pdf, '\n', numbers.n), '\n', -1) link_to_pdf
     FROM
       numbers INNER JOIN refs
       ON CHAR_LENGTH(refs.link_to_pdf)
          -CHAR_LENGTH(REPLACE(refs.link_to_pdf, '\n', ''))>=numbers.n-1
     ORDER BY
       id, n)

tableau de chiffres juste un tableau avec des chiffres :

     CREATE TABLE `numbers` (
       `n` varchar(255) DEFAULT NULL,
       `recnum` bigint(20) NOT NULL AUTO_INCREMENT,
       PRIMARY KEY (`recnum`)
     ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;