Question

在我的应用程序的onCreate()方法中，我使用网络服务器和SQLite脚本将数据从MYSQL数据库上传到PHP数据库。

数据上传正确，但问题是每次应用程序启动时数据库都会填充duplicate个数据。

如何添加validation以确保如果数据库已填充了特定数据，然后do not重新上传，则只上传new数据？

OnCreate（）代码：

// create a instance of SQLite Database
        loginDataBaseAdapter = new LoginDataBaseAdapter(this);
        loginDataBaseAdapter = loginDataBaseAdapter.open();


        ConnectionDetector cd = new ConnectionDetector(LoginHome.this);
        Boolean isInternetPresent = cd.CheckInternet(); // true or false

        if (isInternetPresent) {

            Cursor cur = loginDataBaseAdapter.getSinlgeEntry();

            if (cur != null) {

                cur.moveToFirst();

                while (cur.isAfterLast() == false) {

                    String sessionId = cur.getString(cur
                            .getColumnIndex("sessionid"));
                    String game = cur.getString(cur.getColumnIndex("game"));
                    String name = cur.getString(cur.getColumnIndex("name"));
                    int avgAttention = Integer.parseInt(cur.getString(cur
                            .getColumnIndex("avgattention")));
                    int avgMediation = Integer.parseInt(cur.getString(cur
                            .getColumnIndex("avgmeditation")));
                    int maxAttention = Integer.parseInt(cur.getString(cur
                            .getColumnIndex("maxattention")));
                    int maxMediation = Integer.parseInt(cur.getString(cur
                            .getColumnIndex("maxmeditation")));
                    int score = Integer.parseInt(cur.getString(cur
                            .getColumnIndex("score")));
                    String date = cur.getString(cur.getColumnIndex("date"));

                    if (!sessionId.equals(null))
                        UploadDataAuto(sessionId, game, name,
                                avgAttention, avgMediation, maxAttention,
                                maxMediation,score, date);
                    // }

                    cur.moveToNext();
                }

            }
        }

UploadDataAuto方法：

public void UploadDataAuto(String sessionId, String game, String name,
            Integer score, Integer avgAttn, Integer avgMed, Integer maxAttn,
            Integer maxMed, String date){

        // Defined URL where to send data
        String ServerUrl = "http://ry.net16.net/gameRegistration.php?sessionId="
                + sessionId
                + "&game="
                + game
                + "&name="
                + name
                + "&avgMed="
                + avgMed
                + "&maxMed="
                + maxMed
                + "&avgAttn="
                + avgAttn
                + "&maxAttn="
                + maxAttn
                + "&score="
                + score
                + "&date="
                + date
                + "";

        LongOperation longOperation = new LongOperation();
        longOperation.sessionId = sessionId;
        longOperation.execute(ServerUrl);

    }

私人班级长期操作：

private class LongOperation extends AsyncTask<String, String, Void> {

        // Required initialization
        private final HttpClient Client = new DefaultHttpClient();
        private String Content;
        private String Error = null;
        private ProgressDialog Dialog = new ProgressDialog(LoginHome.this);
        String data = "";
        int sizeData = 0;
        public String sessionId = "";

        protected void onPreExecute() {
            // NOTE: You can call UI Element here.

            // Start Progress Dialog (Message)

            Dialog.setMessage("Please wait.. Data is uploading .");
            Dialog.show();

        }

        // Call after onPreExecute method
        protected Void doInBackground(String... urls) {

            /************ Make Post Call To Web Server ***********/
            BufferedReader reader = null;

            // Send data
            try {

                // Defined URL where to send data
                URL url = new URL(urls[0]);

                // Send POST data request

                URLConnection conn = url.openConnection();
                conn.setDoOutput(true);
                OutputStreamWriter wr = new OutputStreamWriter(
                        conn.getOutputStream());
                wr.write(data);
                wr.flush();

                // Get the server response

                reader = new BufferedReader(new InputStreamReader(
                        conn.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line = null;

                // Read Server Response
                while ((line = reader.readLine()) != null) {
                    // Append server response in string
                    sb.append(line + "");
                }

                // Append Server Response To Content String
                Content = sb.toString();
            } catch (Exception ex) {
                Error = ex.getMessage();
            } finally {
                try {

                    reader.close();
                }

                catch (Exception ex) {
                }
            }

            /*****************************************************/
            return null;
        }

        protected void onPostExecute(Void unused) {
            // NOTE: You can call UI Element here.

            // Close progress dialog
            Dialog.dismiss();

            if (Error != null) {

                // uiUpdate.setText("Output : "+Error);

            } else {

                // Show Response Json On Screen (activity)
                // uiUpdate.setText( Content );

                /****************** Start Parse Response JSON Data *************/

                String OutputData = "";
                JSONObject jsonResponse;

                try {

                    /******
                     * Creates a new JSONObject with name/value mappings from
                     * the JSON string.
                     ********/
                    jsonResponse = new JSONObject(Content);

                    String result = jsonResponse.get("result").toString();

                    if (result.equals("true")) {

                        //loginDataBaseAdapter.deleteUploadedRecord(sessionId);

                        Toast.makeText(LoginHome.this,
                                "Data is successfully uploaded.",
                                Toast.LENGTH_LONG).show();

                    } else {
                        Toast.makeText(
                                LoginHome.this,
                                "Error while uploading. Please try again later.",
                                Toast.LENGTH_LONG).show();
                    }

                }
                /****************** End Parse Response JSON Data *************/

                catch (JSONException e) {

                    e.printStackTrace();
                }

            }
        }

    }

Answer 1

尝试将UNIQUE索引应用于您的列，以避免重复输入，here就是这样。希望它有所帮助！

Answer 2

我有这种情况，我认为这也可能对你有所帮助：

1）在数据库中添加一个名为uploaded的字段，默认值为0

2）选择要上传uploaded = 0

的记录

3）使用您的JSON请求发送记录唯一ID

4）更改您的Web服务以在响应

中发回ID

5）当jsonResponse从响应中获取ID并更新时，在results = true中记录。将字段uploaded设置为1

这将确保所有记录都成功添加到您的数据库，并且只上传新记录。在maht0rz建议的服务器表中应用UNIQUE索引也是一个好主意。希望有所帮助

验证以确保上传的SQLite数据不重复？

2 个答案: