java - 如何发送带参数的查询

Question

我想在我的 Android 应用程序中使用一些参数执行插入查询。

例如在 php 中，它类似于:-

$query ="insert into inventoryproductrel(id, productid, sequence_no, quantity, listprice) values(?,?,?,?,?)";
$qparams = array($id,$prod['prod'],$counter,$prod['pcs'],$prod['price']);
$productadded=$adb->pquery($query,$qparams);

这里 pquery 是一个函数:-

function pquery($sql, $params){
    global $log, $default_charset;
    $log->debug('Prepared sql query being executed : '.$sql);
            $this->checkConnection();

            $this->executeSetNamesUTF8SQL();

            $sql_start_time = microtime(true);
            $params = $this->flatten_array($params);
            if (count($params) > 0) {
                $log->debug('Prepared sql query parameters : [' . implode(",", $params) . ']');
            }

            if($this->avoidPreparedSql || empty($params)) {
                $sql = $this->convert2Sql($sql, $params);
                $result = &$this->database->Execute($sql);
            } else {
                $result = &$this->database->Execute($sql, $params);
            }
            $sql_end_time = microtime(true);
            $this->logSqlTiming($sql_start_time, $sql_end_time, $sql, $params);

            $this->lastmysqlrow = -1;
            return $result;
}

我不知道如何执行此操作，即在 java/android 中使用参数执行查询。

Answer 1

您可以从 Android 应用程序向同一 PHP 脚本发出 POST 请求，并在将值插入数据库之前，设置 POST 参数中的变量值。

使用以下代码发出 POST 请求。确保从 AsyncTask 或单独的线程执行此操作:

public String makePOSTRequestNew(String urlString,
        List<NameValuePair> nameValuePairs) {
    URL url;
    String response = "";
    try {
        url = new URL(urlString);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(10000);
        conn.setConnectTimeout(15000);
        conn.setRequestMethod("POST");
        conn.setDoInput(true);
        conn.setDoOutput(true);

        OutputStream os = conn.getOutputStream();
        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(
                os, "UTF-8"));
        writer.write(getQuery(nameValuePairs));
        writer.flush();
        writer.close();
        os.close();

        InputStream responseStream = new BufferedInputStream(
                conn.getInputStream());
        BufferedReader responseStreamReader = new BufferedReader(
                new InputStreamReader(responseStream));
        String line = "";
        StringBuilder stringBuilder = new StringBuilder();
        while ((line = responseStreamReader.readLine()) != null) {
            stringBuilder.append(line);
        }
        responseStreamReader.close();
        response = stringBuilder.toString();
        conn.connect();
    } catch (IOException e) {
        e.printStackTrace();
    }

    return response;
}

getQuery() 方法从 nameValuePairs 创建参数字符串:

private String getQuery(List<NameValuePair> params)
        throws UnsupportedEncodingException {
    StringBuilder result = new StringBuilder();
    boolean first = true;

    for (NameValuePair pair : params) {
        if (first)
            first = false;
        else
            result.append("&");

        result.append(URLEncoder.encode(pair.getName(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode(pair.getValue(), "UTF-8"));
    }

    return result.toString();
}

这就是您如何使用要 POST 的参数调用方法:

List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("paramName",
                            paramValue));
String insertResponse = makePOSTRequestNew(insertURL, nameValuePairs);