我的PHP正在返回错误信息？

Question

试图让我的PHP脚本返回一些SQL表查询。这里是我的脚本，因为它代表现在：

<?php 

define("DB_HOST", "localhost"); 
define("DB_USER", "*"); 
define("DB_PASSWORD", "*"); 
define("DB_DATABASE", "*"); 

mysql_connect(DB_HOST, DB_USER, DB_PASSWORD); 
mysql_select_db(DB_DATABASE); 


if (isset($_POST['tag']) && $_POST['tag'] != '') { 
    $tag = $_POST['tag']; 
    echo $tag; 
if ($tag == 'question') { 
    $category = $_POST['category']; 
    $response=mysql_query("select * from QUESTIONS where CATEGORY like '$category'"); 
    return $category; //just doing this, rather than $response to see if it works 
} 
} 
?> 

这里还有一个与此相关的Android的代码：

public JSONObject getQuestionsJSONFromUrl(String url, List<NameValuePair> params) { 

    // Making HTTP request 
try { 
     // defaultHttpClient 
     DefaultHttpClient httpClient = new DefaultHttpClient(); 
     HttpPost httpPost = new HttpPost(url); 
     httpPost.setEntity(new UrlEncodedFormEntity(params)); 

     HttpResponse httpResponse = httpClient.execute(httpPost); 
     HttpEntity httpEntity = httpResponse.getEntity(); 
     is = httpEntity.getContent(); 

    } catch (UnsupportedEncodingException e) { 
     e.printStackTrace(); 
    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    try { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(
       is, "iso-8859-1"), 8); 
     StringBuilder sb = new StringBuilder(); 
     String line = null; 
     while ((line = reader.readLine()) != null) { 
      Log.v("while", line); 
      sb.append(line + "\n"); 
      //Log.v("err", line); 
     } 
     is.close(); 

以及调用getQuestionsJSON方法...：

private static String question_tag = "question"; 
public JSONObject getQuestions(String category) { 
    List<NameValuePair> params = new ArrayList<NameValuePair>(); 
    params.add(new BasicNameValuePair("tag", question_tag)); 
    params.add(new BasicNameValuePair("category", category)); 
    //JSONObject json; 
    JSONObject questionsList = jsonParser.getQuestionsJSONFromUrl(questionURL, params); 
    //return json 
    return null; 
} 

这里是Log.v（）的LogCat，我在getQuestionsJSON ...（）方法中有：

04-04 20:41:58.721: V/while(933): question 

所以我真的不明白为什么这是返回'问题'，而不是我运行getQuestions（）时传递的字符串？

Answer 1

在PHP文件，你有

echo $tag; 

而且它是响应请求。

这应返回MySQL的响应：

if (isset($_POST['tag']) && $_POST['tag'] != '') { 
    $tag = $_POST['tag']; 
    if ($tag == 'question') { 
     $category = $_POST['category']; 
     $response=mysql_query("select * from QUESTIONS where CATEGORY like '$category'"); 

     $rows = array(); 
     while($r = mysql_fetch_assoc($response)) { 
      $rows[] = $r; 
     } 
     print json_encode($rows); 
    } 
}