如何使用Where子句android

Question

对于学校项目，我必须将微调器链接到我的数据库。

我已经成功完成了这一步，但现在他们希望微调器只显示与我的应用程序中连接的人的id相关的数据。

我想知道，如何在PHP脚本中发送id？

我尝试过这段代码，但是当我连接后启动应用程序时，我的应用程序崩溃了。

这是我的代码：

package com.example.gardenounou;

import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.sql.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class UserProfile extends Activity {

    EditText nom,prenom,harr,hdep,nbrepas,frais,frais_entretien,frais_transport,date_garde;
    String str_nom,str_prenom,str_harr,str_hdep,str_nbrepas,str_frais,str_fraisentretiens,str_fraistransport,str_date_garde;
    Button valider;
    ArrayList<String> listItems=new ArrayList<>();
    ArrayAdapter<String> adapter;
    Spinner sp;
    Intent intent = getIntent();
    String userId = intent.getStringExtra("id");
    @Override
    protected void onCreate(Bundle savedInstanceState)     {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user_profile);


        harr = (EditText)findViewById(R.id.textharr);
        hdep = (EditText)findViewById(R.id.texthdep);
        nbrepas = (EditText)findViewById(R.id.textnbrrepas);
        frais = (EditText)findViewById(R.id.textfrais);
        valider =(Button)findViewById(R.id.btnvalider);
        frais_entretien = (EditText)findViewById(R.id.tfentretien);
        frais_transport = (EditText)findViewById(R.id.tftransport);
        sp=(Spinner)findViewById(R.id.spinnernom);
        adapter=new ArrayAdapter<String>(this,R.layout.spinner_nom,R.id.txt,listItems);
        sp.setAdapter(adapter);

    }
    public void onStart(){
        super.onStart();

        BackTask(userId);

     }
    private void  BackTask (final String idnounou) {
         @SuppressWarnings("unused")
        class BackTaskClass extends AsyncTask<Void,String,Void>{
        ArrayList<String> list;
        protected void onPreExecute(){
          super.onPreExecute();
          list=new ArrayList<>();
        }
        protected String doInBackground(String...params){
            InputStream is=null;
            String result="";
            String id_nounou = params[0];
            String login_url = "http://192.168.20.135/scriptphp/listinfos.php";
            try{
                 URL url = new URL(login_url);
                 HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                 httpURLConnection.setRequestMethod("POST");
                 httpURLConnection.setDoOutput(true);
                 httpURLConnection.setDoInput(true);
                 OutputStream outputStream = httpURLConnection.getOutputStream();
                 BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
                 String post_data = URLEncoder.encode("id_nounou", "UTF-8")+"="+URLEncoder.encode(id_nounou,"UTF-8");
               // Get our response as a String.
                 bufferedWriter.write(post_data);
                 bufferedWriter.flush();
                 bufferedWriter.close();
                 outputStream.close();
                 InputStream inputStream = httpURLConnection.getInputStream();      

            //convert response to string

               BufferedReader reader = new BufferedReader(new InputStreamReader(is,"utf-8"));           
               String line = null;
               while ((line = reader.readLine()) != null) {
                 result+=line;
               }
               reader.close();
               inputStream.close();
               httpURLConnection.disconnect();

                             //result=sb.toString();
            }catch(Exception e){
               e.printStackTrace();
            }
            // parse json data
            try{
               JSONArray jArray =new JSONArray(result);
               for(int i=0;i<jArray.length();i++){
                  JSONObject jsonObject=jArray.getJSONObject(i);
                  // add interviewee name to arraylist
                  list.add(jsonObject.getString("nom_enfant"));
               }
            }
            catch(JSONException e){
               e.printStackTrace();
            }
            return null;
          }
          protected void onPostExecute(Void result){
            listItems.addAll(list);
            adapter.notifyDataSetChanged();
          }
        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub
            return null;
        }
         }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) 
    {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


    public void Onreg(View view)  
    {
        str_nom = nom.getText().toString();
        str_prenom = prenom.getText().toString();
        str_harr = harr.getText().toString();
        str_hdep = hdep.getText().toString();
        str_nbrepas = nbrepas.getText().toString();
        str_frais = frais.getText().toString();
        str_fraistransport = frais_transport.getText().toString();
        str_fraisentretiens = frais_entretien.getText().toString();
        String type= "infogarde";
        BackgroundWorker registermain = new BackgroundWorker(this);
        registermain.execute(type,str_nom,str_prenom,str_harr,str_hdep,str_nbrepas,str_frais,str_fraisentretiens,str_fraistransport);

    }
}

这是我的脚本php：

<php
    require_once('dbconnect');
    $id_nounou = $_POST['id_nounou];

    $sql="SELECT id_parent,id_enfant,nom_enfant FROM enfants where id_nounou =" .'$id_nounou;
    $result=$mysqli->query($sql);
    while($e=mysqli_fetch_assoc($result)) {
        $output[]=$e; 
    }

    print(json_encode($output)); 
    $mysqli->close();   

?>