my $sql = "
 LOCK TABLE tabreserves IN SHARE MODE;
 SELECT 
  tabreserves.date,
  tabreserves.hour_i,
  tabreserves.hour_e,
  tabreserves.idreserve,
  tabreserves.fk_idfield,
  tabfields.imped,
  tabfields.design

  FROM tabreserves
  LEFT JOIN tabfields ON
   tabfields.idfield = tabreserves.fk_idfield
  WHERE date = ? AND (hour_i < ? AND hour_e > ?)
   AND (fk_idfield = ? OR ? = ANY (imped))
  LIMIT 1
";