现在，我有一个android工作室的活动是一个调查，列出了8个问题。我需要阅读题为“mci表”的调查表中的8个问题，并从“用户表”中获取开始日期和结束日期。我相信这是我的mysql查询的一个问题。我对处理多张table还没有经验，我想知道是否有人能给我指出正确的方向。
android studio java

public void getMCI1Details(){
        final ProgressDialog progressDialog = new ProgressDialog(this);
        progressDialog.setMessage("Loading...");
        progressDialog.show();

        StringRequest stringRequest = new StringRequest(Request.Method.POST, URL_READMCI1,
                new Response.Listener<String>() {

                    @Override
                    public void onResponse(String response) {

                        progressDialog.setMessage("Loading...");
                        progressDialog.show();
                        progressDialog.dismiss();
                        Log.i(TAG, response.toString());
                        try {
                            JSONObject jsonObject = new JSONObject(response);
                            String success = jsonObject.getString("success");
                            JSONArray jsonArray = jsonObject.getJSONArray("read");

                            if(success.equals("1")){
                                for (int i =0; i < jsonArray.length(); i++){
                                    JSONObject object= jsonArray.getJSONObject(i);

                                    String Q1 = object.getString("Q1Medical").trim();
                                    String Q2 = object.getString("Q2Safety").trim();
                                    String Q3 = object.getString("Q3Completing").trim();
                                    String Q4 = object.getString("Q4TP").trim();
                                    String Q5 = object.getString("Q5Supervisor").trim();
                                    String Q6 = object.getString("Q6English").trim();
                                    String Q7 = object.getString("Q7Hours").trim();
                                    String Q8 = object.getString("Q8Additional").trim();
                                    String strStart = object.getString("start_date").trim();
                                    String strEnd = object.getString("end_date").trim();

                                }
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                            progressDialog.dismiss();
                            Toast.makeText(MyCheckIns.this, "Error Reading Details " + e.toString(), Toast.LENGTH_SHORT).show();
                        }
                    }
    },
            new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            progressDialog.dismiss();
            Toast.makeText(MyCheckIns.this, "Error Reading Details " + error.toString(), Toast.LENGTH_SHORT).show();

        }
    })
    {
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
        Map<String, String> params = new HashMap<>();
        params.put("id", getId);
        return params;
    }
    };

        RequestQueue requestQueue = Volley.newRequestQueue(this);
        requestQueue.add(stringRequest);
    }

PHP

?php

if ($_SERVER['REQUEST_METHOD']=='POST') {

    $id = $_POST['id'];

    $conn = mysqli_connect("localhost", "root", "", "users");

    $sql = "SELECT user_table.start_date, 
user_table.end_date, 
mci_table.Q1Medical,
 mci_table.Q2Safety, 
mci_table.Q3Completing, 
mci_table.Q4TP, 
mci_table.Q5Supervisor,
 mci_table.Q6English, 
mci_table.Q7Hours, 
mci_table.Q8Additional FROM user_table, mci_table WHERE user_table.id = mci_table.id";

               $response = mysqli_query($conn, $sql);

    $result = array();
    $result['read'] = array();

    if( mysqli_num_rows($response) === 1 ) {

        if ($row = mysqli_fetch_assoc($response)) {

             $h['Q1Medical']        = $row['Q1Medical'] ;
             $h['Q2Safety']       = $row['Q2Safety'] ;
             $h['Q3Completing']        = $row['Q3Completing'] ;
               $h['Q4TP']       = $row['Q4TP'] ;
              $h['Q5Supervisor']        = $row['Q5Supervisor'] ;
               $h['Q6English']        = $row['Q6English'] ;
               $h['Q7Hours']       = $row['Q7Hours'] ;
                $h['Q8Additional']        = $row['Q8Additional'] ;

                $h['start_date']        = $row['start_date'] ;
                             $h['end_date']       = $row['end_date'] ;

             array_push($result["read"], $h);

             $result["success"] = "1";
             echo json_encode($result);
        }

   }

 }else {

     $result["success"] = "0";
     $result["message"] = "Error!";
     echo json_encode($result);

     mysqli_close($conn);
 }

 ?>