如何SQLite表的值进行比较，以在Android上的JSON标记值 [英] How to compare the value of sqlite table to the json tag value in android

问题描述

我要的id值 sqlite的比较值 TAG_ID 从JSON Web服务来。我只是坚持做这个的。

什么到目前为止，我已经尝试为

 类LOADALL扩展的AsyncTask＆LT;字符串，字符串，字符串＆GT;
    {            保护字符串doInBackground（字符串参数... args）
            {
                Log.i（URL，url_all_products）;                    清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
                    JSONObject的JSON = jParser.makeHtt prequest（url_all_products，GET，则params）;
                    Log.w（所有的书：json.toString（））;
                    Log.i（url_all_products，url_all_products）;
                    尝试
                    {
                        通信System.err.println（JSON数组+ json.getJSONArray（TAG_PRODUCTS））;
                        bookProduct = json.getJSONArray（TAG_PRODUCTS）;                    }
                    赶上（JSONException E）
                    {
                            e.printStackTrace（）;                    }
                    如果（data_exist！= bookProduct.length（））{
                        Log.i（在更新，M这里）;
                         光标光标= getRawEvents（从bcuk_book选择ID）;                             尝试{                             的for（int i = 0; I＆LT; bookProduct.length（）;我++）{
                                 JSONObject的C = bookProduct.getJSONObject（I）                                 字符串买入= c.getString（TAG_ID）;                                 ArrayList的＆LT;串GT;的azazaz =新的ArrayList＆LT;串GT;（）;                                    mapId.add（TAG_ID）;                                    Log.e（出价，出价）;                                    而（cursors.moveToNext（））
                                    {
                                     通信System.err.println（更新codeD STEON+ cursors.getString（0））;
                                     Log.e（投标，c.getString（TAG_ID））;                                    }
                             }                         }
                             赶上（JSONException E）{
                                 e.printStackTrace（）;
                             }
                    }
                    其他{
                        Log.i（完成好，M这里）;
                    }
                    返回null;
            }
 

背后

原因

 如果（data_exist！= bookProduct.length（））{
 

这句话是变量 data_exist = cursor.getCount（）;

和 bookProduct.length 是我要对它们进行比较，如果长度不一样jsonarray的长度，然后我想更新新的值到sqlite的。可以任何一个建议我的办法来做到这一点。

解决方案

  

如果长度不一样的话，我想更新的新值成
  sqlite的。

不更新数据库的好方法。结果
假设有在服务器数据库中的字段的一些变化。同样计数，但内容是不同的。结果，
这是我做的方式：

 字符串SQL =SELECT * FROM+ DB_TABLE +，其中+ TAG_ID +=+身份证+';
 光标C = database.rawQuery（SQL，NULL）;
 c.moveToFirst（）;
 如果（c.getCount（）大于0）{//已经在数据库中
      //与TAG_ID = ID更新条目
  }
  其他{//新条目
      //添加新条目
  }
 

I want to compare the value of the id in sqlite to the value of TAG_ID coming from the json webservice.I just stuck up to do this..

What I have tried so far is

class LoadAll extends AsyncTask<String, String, String> 
    {

            protected String doInBackground(String... args) 
            {
                Log.i("url ",url_all_products);

                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    JSONObject json = jParser.makeHttpRequest(url_all_products, "GET",params);
                    Log.w("All book: ", json.toString());
                    Log.i(url_all_products, url_all_products);                     
                    try 
                    {
                        System.err.println("json array "+json.getJSONArray(TAG_PRODUCTS));
                        bookProduct = json.getJSONArray(TAG_PRODUCTS);

                    } 
                    catch (JSONException e) 
                    {
                            e.printStackTrace();

                    } 
                    if(data_exist!=bookProduct.length()){
                        Log.i("in update","m here");
                         Cursor cursors = getRawEvents("select id from bcuk_book");

                             try{

                             for (int i = 0; i < bookProduct.length(); i++) {
                                 JSONObject c = bookProduct.getJSONObject(i);

                                 String Bid = c.getString(TAG_ID);

                                 ArrayList<String> mapId = new ArrayList<String>();

                                    mapId.add(TAG_ID);

                                    Log.e(Bid,Bid);

                                    while(cursors.moveToNext())
                                    {
                                     System.err.println("update coded STEON"+cursors.getString(0));
                                     Log.e(Bid,c.getString(TAG_ID));

                                    }
                             }

                         }
                             catch(JSONException e){
                                 e.printStackTrace();
                             }
                    }
                    else{
                        Log.i("Done good","m here");
                    }
                    return null;               
            }

The reason behind

    if(data_exist!=bookProduct.length()){

this statement is the variable data_exist=cursor.getCount();

and the bookProduct.length is the length of the jsonarray I want to compare them if the length is not same then I want to update the new values into the sqlite.could any one suggest me the approach to do this

解决方案

if the length is not same then I want to update the new values into the sqlite.

Not a good way to update databases.
Suppose that there is some changes in the server database fields. Same count but the contents is different.
This is the way I do:

 String sql = "select * from " + DB_TABLE + " where " + TAG_ID + "='" + id + "'";
 Cursor c = database.rawQuery(sql, null);
 c.moveToFirst();
 if( c.getCount() > 0){ // already in the database
      // update entry with TAG_ID = id
  }
  else{ // new entry
      // add new entry
  }

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