roomdb | style database that enables programmers | Database library

I have prices of items stored in RoomDb.I want to fetch those prices and sum up in my app but I am unable to do it. This is what I have done so far. I am not able to retrieve the prices and sum them up.

Below is an error:

I'm frustated. I'm looking for a solution over few hours....

I've got a simple room database:

I'm trying to create a table in MySQL using python-flask. The table name is the 'id' parameter, which I pull from my server. I want this id to be the name of the table that I'm creating, but when I try to do so, I get the following error:

'mysql.connector.errors.ProgrammingError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '46490210 (user varchar(50), message varchar(150))' at line 1'

Here's the python-sql code for reference.

I am fairly new to Android Room and SQLite in general, so sorry if this is a simple question.

I am getting data from a API that I'd like to insert into a database so it's accessible when the device is offline.

Depending on the endpoint of the API, some fields of my Data objects may be null (Think a summary with just the basic fields versus a fully detailed object with all fields)

To keep the database clean, I'd like to update the entries, but only the columns that are not null (eg. that I have new values for) and keep the rest of the columns untouched.

Here are some example classes to clarify:

Person

Prehisrory

I have a list of stocks (some objects) from RoomDB. Each one of them have "symbol", "name", "price" and what's most important, "isFavourite" fields. I made a ViewPager2 with two Fragments containing RecyclerView (actually there are just two instances of one class StocksFragment - one for all stocks, one for only favourite stocks). Each stock in RecyclerView is connected to the repository through Obsrver (data changes => stock's ViewHolder changes). Also each ViewHolder has own checkBox that changes "isFavourite" Stock field through StockListViewModel that calls StockRepository, that works directly with roomDB (with kotlin coroutines - sth like fun getStocks(): LiveData> = runBlocking{ stockDao.getStocks() })

Problem

When i click the same checkBox several times in a relatively small amount of time, all RecyclerView's ViewHolders become unclickable (neither the delete button nor the checkbox works). But i still can scroll RecyclerView How can i fix that? I think i am doing something very inefficient but i dont know what.

Here is my StocksFragment code:

I trying to create a custom photo gallery which the user can store Images from MediaStore photo gallery, And my target is that the user can only the store different Image in database, if it is a duplicate Image it will not store .So , Im thinking hey, I can use the filepath as sort of A Id to check for duplicate Images. But evertime I restart the app and repick the same picture the Uri/filepath is not the same espicially the lastpart of the filePath/Uri

My Weird Implementation to Check duplicate:

I'm trying to implement paging on Android using a DataSource implementation, plus PagedAdapter.

Initially, the requirements were to have a full list in memory (not using RoomDB) and I wanted to take a moving "view" over that data as the user scrolls - i.e. feeding it to the adapter in pages. I've accomplished that with the use of PositionalDataSource.

However, now I have a new requirement. Some of the items in the original full list are actually "loading" items (i.e. spinners) and I need to fetch the data that these cells represent in chunks. These chunks have undetermined sizes. When a chunk loads in, the "loading" item should move down the list, and the loaded chunk be inserted where the "loading" item used to be. This should continue until all chunks that the "loading" item represents have been loaded in, at which point the "loading" item at the end of the list should be removed.

This means, my underlying data source actually grows dynamically as the user scrolls through the list. Which I think means PositionalDataSource is not the right type of data source to use as the source docs state:

1. Entity (table) CurrentyEntity.java

I have roomdb dao take SupportSQLiteQuery , with single table it works great and fine , the dark come with relations