Question

我有一个objectId列表，我试图在另一个类中检索另一个列表，其中指针值等于当前parseObject的objectId。

我意识到我正在将字符串“objectId”与指针“threadPointer”进行比较，所以如果objectId等于threadPointer _Pointer值，有人可以帮我查询从类中检索项目列表

public void retrieveThreadListStoreInDB()
{
    ParseQuery<ParseObject> query = ParseQuery.getQuery("Threads");
    query.include("postedBy");
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> list, ParseException e) {
            if (e == null) {
                // Query is successful now lets load data from parse
                ParseObject.pinAllInBackground((List<ParseObject>) list, new SaveCallback() {
                    @Override
                    public void done(ParseException e) {
                        if (e == null) {
                            if (!isFinishing()) {
                                // TODO : Notify to refresh data
                            }
                        } else {
                            Log.d("DEBUG", "ERROR PINNING DATA WITH EXCEPTION : " + e);
                        }
                    }
                });

            }
        }
    });

}

public void retrievePostsListStoreInDB()
{
    ParseQuery<ParseObject> query = ParseQuery.getQuery("Posts");
    query.include("postedBy");
    query.include("threadPointer");
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(final List<ParseObject> list, ParseException e) {
            if (e == null) {
                // Query is successful now lets load data from parse
                ParseObject.pinAllInBackground((List<ParseObject>) list, new SaveCallback() {
                    @Override
                    public void done(ParseException e) {
                        if (e == null) {
                            if (!isFinishing()) {
                                // TODO : Notify to refresh data
                                Log.d("DEBUG: ","Finished retrieval");
                                Log.d("DEBUG", list.toString());
                                ParseObject object = (ParseObject)list.get(1).get("threadPointer");
                                Log.d("DEBUG_THREAD_POINTER", object.getObjectId());
                            }
                        } else {
                            Log.d("DEBUG", "ERROR PINNING DATA WITH EXCEPTION : " + e);
                        }
                    }
                });

            }
        }
    });

}

这是我从本地db检索ThreadList的地方

            public void retrieveThreadList(){
            List<ParseObject> parseObjectList = new ArrayList<ParseObject>();
            ParseQuery<ParseObject> query = ParseQuery.getQuery("Threads");
            query.orderByDescending("updatedAt");
            query.fromLocalDatastore();

            // Data retrieval was successfull

            try {
               parseObjectList= query.find();
            } catch (ParseException e) {
                e.printStackTrace();
            }
            for (ParseObject parseObject : parseObjectList) {
                String title = (String) parseObject.get("threadTitle");
                ParseUser parseUser = (ParseUser) parseObject.get("postedBy");
                String profilePictureUrl="local";
                try {
                    profilePictureUrl = ((ParseFile) parseUser.get("profilePicture")).getUrl();
                }catch (Exception exception)
                {
                    Log.d("DEBUG_FB","profilePicture not retrieved");
                }

                String threadObjectId = parseObject.getObjectId();
                Log.d("DEBUG_FB_THREAD_ID",threadObjectId);
                ParseQuery parseQueryToRetrievePosts = ParseQuery.getQuery("Posts");
                parseQueryToRetrievePosts.fromLocalDatastore();

//----****** NEED HELP HERE ******----
parseQueryToRetrievePosts.whereEqualTo("threadPointer",parseObject.getObjectId());
                try {
                    List<ParseObject> postsList = parseQueryToRetrievePosts.find();
                    Log.d("DEBUG_FB_POSTS_LIST",postsList.toString());
                } catch (ParseException e) {
                    e.printStackTrace();
                }
    /* To retrieve data over the network --- THIS WORKS WELL BUT I DONT WANT A NETWORK CALL
                ParseRelation <ParseObject> posts = parseObject.getRelation("postMessage");
                ParseQuery postsQuery = posts.getQuery();
                List<ParseObject> postsList = new ArrayList();
                try {
                    postsList=postsQuery.find();

                    for (ParseObject parseObject1: postsList)
                    {
                        String postMessage = (String)parseObject1.get("postMessage");
                        Log.d("DEBUG_FB_MSG", postMessage);
                    }
                    Log.d("DEBUG_FB_POSTS", postsList.toString());
                }catch (Exception e)
                {

                }
    */


                threadModelStore threadObject = new threadModelStore(title,profilePictureUrl);
                Log.d("DEBUG_FB", profilePictureUrl);
                Log.d("DEBUG_FB", title);
                threadItemList.add(threadObject);
            }

先生，我的情况是我有这些课程

THREADS（Class），它有POSTS（与_POSTS的关系）类我想要检索特定线程的相关帖子。我无法确定   与本地数据存储的关系，如果有办法，请告诉我   这样做？ - （UNSOLVED）

所以我想做的是比较POSTS中的线程指针上课并检索相关的帖子。为此，我需要比较一个字符串对象id到指针字段_ThreadPointer在POSTS类中建议一个可能的解决方案 - 求助（VED）。

Answer 1

ParseObject threadPointer=ParseObject.createWithoutData("Pointer_class_Name", "pointer_object_id");

    ParseQuery<ParseObject> query=ParseQuery.getQuery("className");
    query.whereEqualTo("_Pointer", threadPointer);
    query.include("_Pointer");
    query.findInBackground(new  FindCallback<ParseObject>() {

        @Override
        public void done(List<ParseObject> listCommunity, ParseException e) {
            // TODO Auto-generated method stub
            Log.d(TAG, "done");
            if(e==null){
              // access your data
            }else{
             // Error in retrieving data 
            }

根据对象ID从解析中检索数据？

1 个答案: