Inserting data from android application to PostgreSQL database using PHP web service issue

Question

I'm tearing my hair out over this problem I am having. I am trying to allow a user to upload some data from their android application to a website service which I have developed.

The data is to be uploaded using JSON and Android to a PHP web service which will then 'INSERT' the data into my PostgreSQL database.

I am unsure where the logic error is in my whole application as the app produces no errors at runtime but when I check the database records of my PostgreSQL server space there has been no data committed.

Please see below the code I am using and please try to help identify where I am going wrong. I have looked for tutorials on Google but they all are based on reading data FROM a PHP web service to an android app but I am looking to send the original data from the android app.

DataPost Activity

public void postData() throws JSONException{
       Toast.makeText(DataSummary.this, "Done! Check your profile online to see your record.", Toast.LENGTH_LONG).show();

       Thread trd = new Thread(new Runnable(){
           public void run(){
             //Create a new HttpClient and Post Header
               HttpClient httpclient = new DefaultHttpClient();
               HttpPost httppost = new HttpPost("http://users.aber.ac.uk/dwd/mfb/php/jsonscript.php");
               JSONObject json = new JSONObject();

               Bitmap bitmapOrg = BitmapFactory.decodeResource(getResources(), i);
                ByteArrayOutputStream bao = new ByteArrayOutputStream();
                bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 90, bao);
                byte[] ba = bao.toByteArray();
                String ba1=Base64.encodeToString(ba, i);

               try {
                   //JSON data:
                   json.put("photo", ba1.toString());
                   json.put("name", name);
                   json.put("description", description);
                   json.put("latitude", latitude);
                   json.put("longitude", longitude);
                   json.put("project", project);
                   json.put("owner", username);

                   JSONArray postjson = new JSONArray();
                   postjson.put(json);

                   //Post the data
                   httppost.setHeader("json", json.toString());
                   httppost.getParams().setParameter("jsonpost", postjson);

                   //Execute HTTP Post Request
                   System.out.println(json);
                   HttpResponse response = httpclient.execute(httppost);

                   //for JSON
                   if(response != null)
                   {
                       InputStream is = response.getEntity().getContent();

                       BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                       StringBuilder sb = new StringBuilder();

                       String line = null;
                       try{
                           while((line = reader.readLine()) != null){
                               sb.append(line + "\n");
                           }
                       } catch (IOException e){
                           e.printStackTrace();
                       } finally {
                           try {
                               is.close();
                           } catch(IOException e){
                               e.printStackTrace();
                           }
                       }
                   }

               } catch(ClientProtocolException e){
                   e.printStackTrace();
               } catch (IOException e){
                   e.printStackTrace();
               } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
           }
       });
       trd.start();
   }

PHP Webservice

<?php
session_start();
$conn = pg_connect("database_string");

//VARIABLES TO BE WRITTEN TO THE DATABASE
$photo = $_REQUEST["photo"];

echo $photo;
$binary=base64_decode($photo);
header('Content-Type: bitmap; charset=utf-8');

$name = json_decode(stripslashes($_POST["name"]));
$safe_name = pg_escape_string($name);
$desc = json_decode(stripslashes($_POST["description"]));
$safe_desc = pg_escape_string($desc);
$latitude = json_decode(stripslashes($_POST["latitude"]));
$longitude = json_decode(stripslashes($_POST["longitude"]));
$project = json_decode(stripslashes($_POST["project"]));
$owner = json_decode(stripslashes($_POST["owner"]));

$id = pg_query("SELECT * FROM users WHERE email = $owner");
$id_assoc = pg_fetch_assoc($id);
$id_res = $id_assoc['u_id'];

//SQL STATEMENT HERE FOR INSERT

$res = pg_query("INSERT INTO records (photo, name, description, latitude, longitude, project, owner) VALUES ('$photo', '$safe_name', '$safe_desc', '$latitude', '$longitude', '$project', '$id_res'");

pg_close($conn);

?>

Anyone who can provide some advice/tutorials/code solutions would be a hero in my book!

Answer 1

Does the SELECT query return anything? I'm not a PHP expert but to me it looks like you're sending the variables wrong so there shouldn't be:

$id = pg_query("SELECT * FROM users WHERE email = $owner");

But

$id = pg_query("SELECT * FROM users WHERE email ='".$owner."'");

Similar for the INSERT query. Other thoughts:

• don't do a SELECT * when you just want one column it will be slower. For example with index-only-scans in 9.2 you could return the id straight from the index(email,id)
• if you want to use just the id of the user it's better to put it in the subquery of the insert query INSERT INTO records ( ... ,owner) VALUES (... ,(SELECT id FROM users WHERE email='".$owner."')") You could even add RETURNING owner at the end to get the owner id out from the insert query if you need it somewhere else.