如何過濾數據庫輸出？ （android php）

Question

我正在用戶登錄的地方構建一個移動應用程序，並輸出名爲「公告」的數據庫表格的內容。

我想要做的是根據存儲用戶的「accounts」表中的「department」列過濾掉這些輸出。

「公告」表格具有名爲「receiver」的列。

僅當登錄的用戶的「部門」列與「公告」列的「接收者列」具有相同的值或者接收者的值爲「全部」時，內容纔會顯示。

我該怎麼做？

我的PHP腳本

<?php 
$host="localhost"; //replace with database hostname 
$username="root"; //replace with database username 
$password=""; //replace with database password 
$db_name="sunshinedb"; //replace with database name 

$con=mysql_connect("$host", "$username", "$password")or die("cannot connect"); 
mysql_select_db("$db_name")or die("cannot select DB"); 
$sql = "select * from announcement"; 
$result = mysql_query($sql); 
$json = array(); 

if(mysql_num_rows($result)){ 
    while($row=mysql_fetch_assoc($result)){ 
     $json['services'][]=$row; 
    } 
} 
mysql_close($con); 
echo json_encode($json); 
?> 

Java類

JSONObject jsonobject; 
JSONArray jsonarray; 
ListView listview; 

ArrayList<HashMap<String, String>> arraylist; 
ProgressDialog mProgressDialog; 

JSONParser jsonParser = new JSONParser(); 
String email; 

String[] services; 

private String url = "http://10.0.3.2/sunshine-ems/services.php"; 

String user_id; 

// ALL JSON node names 
private static final String TAG_TRANS_ID = "announcement_id"; 
private static final String TAG_DATE = "date"; 
private static final String TAG_SERVICES = "title"; 

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.videos_layout); 

    // get listview 
    ListView lv = getListView(); 

    lv.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> arg0, View view, int arg2, 
       long arg3) { 

      Intent i = new Intent(getApplicationContext(), 
        Single_List.class); 

      String transaction_id = ((TextView) view 
        .findViewById(R.id.transac_id)).getText().toString(); 

      i.putExtra("announcement_id", transaction_id); 

      startActivity(i); 
     } 
    }); 

    new DownloadJSON().execute(); 
} 

// DownloadJSON AsyncTask 
private class DownloadJSON extends AsyncTask<String, String, String> { 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     // Create a progressdialog 
     mProgressDialog = new ProgressDialog(VideosActivity.this); 
     // Set progressdialog title 
     mProgressDialog.setTitle("Loading Services"); 
     // Set progressdialog message 
     mProgressDialog.setMessage("Loading..."); 
     mProgressDialog.setIndeterminate(false); 
     // Show progressdialog 
     mProgressDialog.show(); 
    } 

    @Override 
    protected String doInBackground(String... params) { 

     JSONObject json = JSONfunctions.getJSONfromURL(url); 

     // Check your log cat for JSON reponse 
     Log.d("Service history ", json.toString()); 

     // Create the array 
     arraylist = new ArrayList<HashMap<String, String>>(); 

     try { 
      // Locate the array name 
      jsonarray = json.getJSONArray("services"); 

      for (int i = 0; i < jsonarray.length(); i++) { 
       HashMap<String, String> map = new HashMap<String, String>(); 
       json = jsonarray.getJSONObject(i); 

       String transac_id = json.getString(TAG_TRANS_ID); 
       String date = json.getString(TAG_DATE); 
       String service = json.getString(TAG_SERVICES); 

       // Retrive JSON Objects 
       map.put(TAG_SERVICES, service); 
       map.put(TAG_DATE, date); 
       map.put(TAG_TRANS_ID, transac_id); 

       // Set the JSON Objects into the array 
       arraylist.add(map); 
      } 
     } catch (JSONException e) { 
      Log.e("Error", e.getMessage()); 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    @Override 
    protected void onPostExecute(String file_url) { 
     mProgressDialog.dismiss(); 
     // updating UI from Background Thread 
     runOnUiThread(new Runnable() { 
      public void run() { 

       /** 
       * Updating parsed JSON data into ListView 
       * */ 
       ListAdapter adapter = new SimpleAdapter(
         VideosActivity.this, arraylist, 
         R.layout.listview_services, new String[] { 
           TAG_TRANS_ID, TAG_SERVICES, TAG_DATE }, 
         new int[] { R.id.transac_id, R.id.txt_service, 
           R.id.txt_date }); 
       // updating listview 
       setListAdapter(adapter); 

      } 
     }); 

    } 
} 

Answer 1

你是不是在你的代碼進行任何過濾的任何地方......

的步驟去做它應該是這些的（按此順序）：

1. Android的側面：調用您的Web服務（PHP代碼）與用戶的部門（以GET或POST參數）
2. WS方：用像SELECT * FROM announcement WHERE receiver = '<department'> OR receiver = 'ALL'，其中部門用戶的部門
3. WS側請求您的數據庫：構建JSON響應
4. 的Android側：處理JSON響應以顯示結果

使它像這樣的優點：

1. 極限數據的數目（限制Android設備上的網絡消耗，並限制PHP服務器的負載）
2. 限制處理Android數據的數據數量（限制Android應用程序的負載：它不是桌面應用程序！決不原諒）

！PS：讀您的文章和你的評論，我真的覺得你應該考慮這些問題開始讓你的應用程序之前：SQL請求，PHP MySQL的訪問（如@Jay指出Blanchard），Web服務和HTTP協議，Android AsyncTask