<?php
session_start();
$conn = oci_connect('insidedba', 'progetto16', 'localhost/XE');
if (!$conn) {
    $e = oci_error();
    trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}
echo "<input id="numero" list="posti1" >
          <datalist id="posti1" >";
$sql = oci_parse($conn,"SELECT NUMERO FROM POSTI WHERE PRENOTAZIONE=NULL");
oci_execute($sql);

foreach ($dbo->query($sql) as $row) {
    echo "<option value="$row[numero]"/>"; // Format for adding options
}
echo "</datalist>";
?>

Parse error: syntax error, unexpected 'numero' (T_STRING), expecting ',' or ';' in C:xampphtdocstry.php on line 8

echo "<input id='numero' list='posti1' ><datalist id='posti1'>";

echo "<input id="numero" list="posti1" ><datalist id="posti1" >";

echo "<input id="numero" list="posti1" >
      <datalist id="posti1" >";

echo '<input id="numero" list="posti1" >
      <datalist id="posti1">';