SELECT issue moving from PG_query to PDO - sql

Question

I have a select statement see below. Using PDO how would I recreate this same Select statement, as I want to grab two values from it and combine them into the $geomstring. I can figure out the combine, but not the first 3 lines.
$sql1 = "SELECT easting_value, northing_value FROM gridreference_tbl WHERE gridref_id='$_POST[gridref_id]'";
$result1 = pg_query($sql1);
$row1 = pg_fetch_array($result1);
$geomstring = $row1['easting_value']. $_POST['grid_eastings']." ".$row1['northing_value'].$_POST['grid_northings'];
*php website for prepared statements says *
$stmt = $dbh->prepare("SELECT * FROM REGISTRY where name = ?");
if ($stmt->execute(array($_GET['name']))) {
while ($row = $stmt->fetch()) {
print_r($row);
}
}
I have something similar working for populating a dropdown that partly uses this
$stmt = $conn->prepare("SELECT easting_value, northing_value FROM gridreference_tbl WHERE gridref_id=$gridref_id");
$stmt->setFetchMode(PDO::FETCH_OBJ);

Answer 1

Found it on php.net, I was googling the wrong stuff:
$stmt4 = $conn->prepare("SELECT easting_value, northing_value from gridreference_tbl WHERE gridref_id = 4");
$stmt4->execute();
print("PDO::FETCH_ASSOC: ");
print("Return next row as an array indexed by column name\n");
$result = $stmt4->fetch(PDO::FETCH_ASSOC);
print_r($result);
print("\n");