Looping dalam looping (2) - PostgreSQL

DO $$
    Declare idmaset int;   
      declare idkrtaset int;   
        Declare bulanke int;   
        DECLARE idasetinv int;   
        Declare jwl date;

    cur1 CURSOR for select ID from m_aset_inventaris
                                    where id_bpr = 2 and id_bpr_cabang = 1;   
   
    cur2 cursor for select id, depresiasi_bulan_ke, id_aset_inventaris, jwl_depresiasi
                                    from m_kartu_aset_inventaris where id_aset_inventaris=idmaset
                                    order by depresiasi_bulan_ke;
   
 begin 
OPEN Cur1 ; 
Loop    

    FETCH  next from Cur1 INTO idmaset;    
    EXIT WHEN NOT FOUND;
   
    open cur2;
        loop
       
        FETCH  next from Cur2 INTO idkrtaset, bulanke, idasetinv, jwl;    
    EXIT WHEN NOT FOUND;


    update m_kartu_aset_inventaris
    set jwl_depresiasi=((select jwl_depresiasi from m_kartu_aset_inventaris where depresiasi_bulan_ke < bulanke  and id_aset_inventaris=idasetinv order by depresiasi_bulan_ke desc limit 1) +(interval '1 MONTH'))
    where id_aset_inventaris=idasetinv and depresiasi_bulan_ke=bulanke and depresiasi_bulan_ke >1;
   
        END LOOP;
  CLOSE cur2;
   
end loop ;  
CLOSE Cur1; 
END $$;