title: Check registered user in flutter signup php & mysql
body: <p>I have flutter app with user registration check by php &amp; mysql. I'm searching around in php like :</p>
  
  <pre><code> $sqlUser = "SELECT * FROM users WHERE username = '".$username."'";
      $rs = mysqli_query($con ,$sqlUser);
      $numUsers = mysqli_num_rows($rs);
  
      if($numUsers &gt; 0) {
          echo "User already exists&lt;br/&gt;";
      }
  </code></pre>
  
  <p>and this is my php script for creating user :</p>
  
  <pre><code> &lt;?php
   require_once 'connectdb.php';
  
    $user_id= $_POST['id'];
    $username = $_POST['email'];
    $password = $_POST['password'];
    $nama = $_POST['name'];
    $nik = $_POST['nik'];
    $lahir = $_POST['born'];
    $tentang = $_POST['about'];
    $pengalaman = $_POST['exp'];
    $linkedin = $_POST['linkedin'];
  
  
  $query="INSERT INTO user_info(id, email, password, name, nik, born, about, exp,linkedin)
       VALUES ('$user_id','$username','$password','$name','$nik', '$born', '$about', '$exp', '$linkedin')";
      $exeQuery = mysqli_query($con, $query) ;
  
       if($exeQuery){
       echo (json_encode(array('code' =&gt;1, 'message' =&gt; 'Ajouter avec succée')));
  }else {echo(json_encode(array('code' =&gt;2, 'message' =&gt; 'Non Terminer')));
   }
  
  
   ?&gt;
  </code></pre>
  
  <p>my flutter sign up : </p>
  
  <pre><code>void _register() async {
      setState(() {
        _isLoading = true;
      });
      var url = "url/newuser.php";
  
      await http.post(url, body: {
        "email": _emailController.text,
        "password": _passwordController.text,
        "name": _nameController.text,
        "nik": _nikController.text,
      });
      setState(() {
        _isLoading = false;
      });
      onCreatedAccount();
      //print(_adresseController.text);
    }
  </code></pre>
  
  <p>but how do i pass it to my flutter app, so my app knows that it has registered email/user?</p>