Sql problems with disntinct

Question

I have a table in my database with:

• horarioId
• horarioParagemId
• horarioLinhaId
• horarioHora

Do INNER JOIN of the table rows:

• linhaId
• linhaNome

Do INNER JOIN of the table stops:

• paragemId
• paragemRua
• paragemLatitude

• paragemLongitude

  Example of the schedule table

Horarioid : 1 scheduleParagemId : 3 hourly Table : 4 hourly Time :22:00:00

Horarioid : 2 scheduleParagemId : 3 hourly Table : 4 hoursHora :21:00:00

The goal is to only receive the coordinates where the id of the stops are different. The code I made works with paragemLatitude or paragemLongitude, but does not work with paragemId

include_once('seguranca.php');
protegePagina();

$sql="SELECT DISTINCT horarioParagemId
      FROM horarios
      INNER JOIN paragens ON paragemId = horarioParagemId
      INNER JOIN linhas ON horarioLinhaId = linhaId
      WHERE horariolinhaId = " . $_GET['filtrapronto'];

$_SESSION['latitudefiltra']= array();
$_SESSION['longitudefiltra']= array();
$result=mysqli_query($con,$sql);

while($dados=mysqli_fetch_array($result)) {

    $_SESSION['latitudefiltra'] [] = $dados['paragemLatitude'];
    $_SESSION['longitudefiltra'] []  = $dados['paragemLongitude'];
}

$obj = new stdClass();
$obj->Latitudes=$_SESSION['latitudefiltra'];
$obj->Longitudes=$_SESSION['longitudefiltra'] ; 
echo json_encode($obj);