<?php

  $host = 'localhost';
  $user = 'devel';
  $password = '********';
  $database = 'Cadastro';

  $connect = mysqli_connect($host, $user, $password, $database) or die(mysqli_error());
  $consult = $_GET['q'];

  if(isset($_GET['q'])){
      $sql = mysql_query("SELECT * FROM `Cadastro` WHERE `nome` LIKE $consult");
      echo $sql;
  }
  else {
      echo 'nao foi encontrado nada';
  }
?>

$sql = mysql_query("SELECT * FROM `Cadastro` WHERE `nome` LIKE '$consult'");

$connect = mysqli_connect($host, $user, $password, $database);
$consult = isset($_GET['q']) ? mysqli_real_escape_string($connect, $_GET['q']) : '';

$query = mysqli_query($connect, "SELECT * FROM `Cadastro` WHERE `nome` LIKE %$consult%") or die(mysqli_error($connect);
while($row = mysqli_fetch_assoc($query)){
    echo $row['nome'] .' - '. $row['idade'] .'<br>';
}