How to download certain amount of JSON using volley - android

Is there any way to download a certain amount of rows from JSON?
I have a MySQL database converted to JSON.
The JSON data is large and more than 1000 rows. obviously, i cannot download and parse all of them into my SQLite database in android at once.
I need to download a few rows and load more on Recyclerview scrolling. How can i tell volley to load a few of JSON rows not all of them?

Use LIMIT while detching the Data using SQL Query for fetching Data from MYSql Server.
SELECT * FROM your_table WHERE your_condition LIMIT number_of_rows;
This will Return only Return number_of_rows rows while fetching Data.
SELECT * FROM your_table WHERE your_condition LIMIT starting_row,ending_row;
This will Return only Return n number of rows starting from starting_row to ending_rowwhile fetching Data.

With pagination you can achieve this. Basically at server side you create API which will return some set of data like 50 set or 100 or may be more than that, So whenever you will load that set in your ListView or RecyclerView and on click of Load More or scroll end you call same API again to fetch other set of data and load in app.
If you are using Volley then use same logic to achieve it

Related

How can i correctly access the data in my database using room library

List<Game> gamesList = db.gameDao().getAll();
I am trying to iterate through the list and make use of the data in the database, the command successfully receives the rows but how can I use the content of each row
You got the List already. now you can loop through and get the data like this
for(Game singleGameItem: gameList)
singleGameItem.memberObj

How should i use data that i fetch from webserver, in android

I try to show data which i fetch from rest webservice (spring), in list(RecyclerView). Data can consist of thousands of rows. How should i use these data ?
should i fetch all data(or 100 rows ) and store them in local and read them from local to view in list. if i use these , how should i refresh local data ?
should i fetch 20 rows and view them , when user scroll down and arrive last item , i fetch another 20 rows ?
or should i use another way ?
If i store all data as array , it can throw outofmemoryexception . are there any tutorial or key words to search ?
How twitter or instagram use these data ? There can be a lot of items in twitter list ,but it doesn't crash and twitter can show items which downloaded before, offline(it means store data in local ,isnt' it ?)
To make app work smoother with RecyclerView, use Endless Scrolling.
Load 20 items at a time, apply pagination on your server API call.
Cache every response from server to local storage using OKHttp Response Caching.
Create a local database, store all data you already loaded inside the DB and add a "freshness" like a timestamp if your data is subject to change. If your data items are huge, consider loading an "index" of your data first, then load the individual details later.
Definitely you should not fetch all the data at once. Read about Pagination for dynamic data in android. Recycler View also uses inbuilt pagination for static data but in case of dynamic data i.e. when you are retrieving data from your api, you should send requests to your api when the user scrolls down the list to fetch the next set of data. In order to do that you'll have to extend RecyclerView's OnScrollListener and override the OnScrolled method.

Custom List view adapter only showing 100 entries

I didn't use parse query adapter, instead I made a custom adapter and passed all the text and images in that but Parse only loads 100 items. Can anyone tell me how to get to the next page of the database without using the parse query adapter?
This is a well known problem, the default limit is 100, you should use (saying that you have a query which is a ParseQuery object), you need to call the query.setLimit(int N) where N represents the number of results that you want returned .

Android inserting 5000 records in listview

Hi i would like to know the best way to update listview with 5000 record from the database,do i need to query all the records first and update the listview (what adapter should i use), without any pagenation or using infinitescroll library.and also is there any limit for sqllite, what is the max limit of sqllite

pagination in listview

Thanks in advance.
I am developing a Car Review Application, where user can log in and displayed all the review from the Database. All the the data is being stored in MYSQLdatabase first. I am using json to connect to the MYSQLdatabase and SQLiteDatabase. But the problem is that, after log in the application screen huge no. of data is coming from the server and it is being inserted in our SQLite Database.
After that it is being retrieved from database and displayed in the Application Screen in a list view, it is taking a longer time to displayed all the data in list view. In that case, I am using a SimpleCursorAdapter to retrieve all the data from database.
So is there any way like pagination or something like that to make the data retrieval faster.
Please help me by giving some source code.
You can use something like:
Page 1:
SELECT * FROM YOUR_TABLE LIMIT 20 OFFSET 0
Page 2:
SELECT * FROM YOUR_TABLE LIMIT 20 OFFSET 20
Reference: http://sqlite.org/lang_select.html
You can use the concept of Asynchronous tasks along with SimpleCursorAdapters.
"AsyncTask enables proper and easy use of the UI thread. This class allows to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers."
Here's what you can do:
1) Retrieve only 1st 10/15 items in the 1st query.
2) Fire another query as a background task, while user is checking out first 10/15 items.
This will certainly make the User experience faster
Using the LIMIT keyword from MYSQL you can achieve pagination.
LIMIT allows you to control the number of rows returned by query:
Example:
to show first 10 records
SELECT * FROM Student LIMIT 10 //for first time
to show rows between 10 and 20
SELECT *FROM Student LIMIT 9, 10 //after showing the records first time
LIMIT works for SQLiteDatabase also

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