特定列的Android JSON Fetch Record

Question

我想使用JSON Parsing获取特定列的记录。这是我的PHP MySql的屏幕截图，其中包含一些数据。

以上是我想在微博我的Android应用程序中获取cat_id = 2的所有记录。但是我无法理解如何做到这一点。可以请一些人帮助我。谢谢你提前。

Answer 1

创建一个PHP代码来获取行并将其打印在JSON fromat

中

    $res=mysql_query("select * from table_name where cat_id = '2'") or die(mysql_error());
    $assInfo = array();
    $num=mysql_num_rows($res);
    if($num>0){
        $obj=mysql_fetch_array($res);
        $assInfo["first"]=$obj["column_name"];
        $assInfo["second"]=$obj["another_column"];
        array_push($response["info"], $assInfo);
    }else{
        $response["success"] = 0;
    }
    echo json_encode($response);

并在android中启动Asynctask以在后台抓取打印文本。

public class gettingData extends AsyncTask<Void, Void, Void> {

private String jsonResult;

public gettingData() {
}

@Override
protected Void doInBackground(Void... arg0) {
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    params.add(new BasicNameValuePair("canpass", "herevalue"));
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(url);
    try {
        httppost.setEntity(new UrlEncodedFormEntity(params));
        HttpResponse response = httpclient.execute(httppost);
        jsonResult = inputStreamToString(response.getEntity().getContent())
                .toString();
        Log.v("jr", jsonResult);
    }

    catch (ClientProtocolException e) {
        Log.e("e", "error1");
        e.printStackTrace();
    } catch (IOException e) {
        Log.e("e", "error2");
        e.printStackTrace();
    }
    return null;
}

@Override
protected void onPostExecute(Void result) {
if (jsonResult != null) {
        try {
            if (jsonResponse.optString("success").matches("0")) {
                 //your code for no rows selected
            }else{
                 JSONArray jsonMainNode = jsonResponse.optJSONArray("info");
                JSONObject jsonChildNode = jsonMainNode.getJSONObject(0);
                String first = jsonChildNode.optString("first");
                String second = jsonChildNode.optString("second");
        } catch (JSONException e) {
            e.printStackTrace();
        }
    } else {
        Toast.makeText(context, "Connection Time Out", Toast.LENGTH_LONG)
                .show();
    }
}

在您的活动中执行此类 -

new gettingData().execute();