I have an android app that I have been working on and I created a sqlite database using the android.database.sqlite package. I know that you can access that data by using Android Studio manually, but I am trying to save data into the database so that if one user of the app does something to add to the database, another user of the app will have the same access to the database. Will the android.database.sqlite package allow this or will the database for each user be unique to that user? If this is the case in which all users cannot access the same database after updating, what is the best way to go about creating a database that would let every user access it even when updates occur?
It is possible to add multiple users to a local application. Here is the simplest way to accomplish this:
1) Create a table for users in your database, with a user ID
2) Every user specific value in other tables should be marked to corresponding users with this ID
3) When you fetch the data from database, use the Select statement specifying user
Tip: Android has an Object-Relational-Mapping Library called Room for making database creation simpler. Reading about Room would help too! Take database classes for gaining knowledge about such common tasks.
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It's not a code problem but it's just by my curiosity.
I am making an application that can be logged in by social login, and also email login.
In my application, I plan to use some SQLiteDatabase to save simple datas.
However, when I just save it with A account and login with different account, won't there be conflict because its the same device and server is not intervened with it? How do you know it's different account when its the same device, one application?
Think its sort of a silly question maybe, but if there's a way that everyone uses to solve it, I would like to know.
There can be two cases -
You want to use same database for different users -
In this case, there is no problem as your SQLite database gets saved in your app's /data/data folder which will be always accessible from inside your app.
You want to use different database for different users -
In this case, you have to add user_id column in all the tables of your SQLite database, and based on your user_ids, you can do your database actions like query, deletion, etc
I have a phone application that uses a database of words and tests a user to see which words they know. I have a SQLite database with the words that I populate using a console application and this is then deployed as a resource to phones etc.
When the user runs the application then it stores pass fail data in the same database but in different tables.
When I update the application a fresh copy of the words database is installed on the phone and all the user data is lost.
How is this typically handled? Do phone applications that use SQLite have multiple databases with one being used to store user data and the other holding data which can be brought in when the application is first installed or updated?
If multiple databases are used then is it possible to create a look up from one database to the other?
Thanks in advance for any help, advice or links that point me in the right direction.
I would use a file (JSON, or plain text) to ship the words with the app. Then, when the app runs, it reads that file and adds the new words to the database. This won't affect the other tables.
Instead of having to deal with that, we hard code the values into a static method in code. Then at runtime, we see if there is any data in the table and, if not, we grab the hard coded data and do an insert.
In your case, I would also just add a version number of some kind so then, if the version was lower or the table was empty, you do a delete all and then insert your new static data.
I using SQLite as my database.
Using the app, the user can save some item on the database.
But I would like also to update the database from time to time.
The problem is how can I update the database without affecting the user inserted data and in a manner that it will download the new database online and not by updating the app itself.
Since my comment is large, I'll post it as an answer.
You won't find any tutorial showing exactly what you're trying to accomplish, because what you need is somewhat complex (but not difficult)
First approach:
You need your app to query some webservice to find out if there's a newer version of the database, and if there is, download it
The database must be saved in some temporary location, then you transfer all the users saved data to the new database, and finally replace the apps database with the new database (already updated with user's data)
Another approach would be:
Make your app query some webservice to find if the database needs to be updated.
If yes, download the SQL commands to modify the database structure.
Currently I have developed an android application that uses a local sqlite database per installation. The database comes pre-populated with static tables, and the entire point of the application is to allow the user to assign dates/comments with the pre-populated information in each table.
I am looking to bring this online, and move the database to a mysql format, allowing access via desktops and other mobile devices. Is the best way to handle this to assign each new user a new database?
I would strongly avoid creating multiple databases, and instead add relationships to the existing database structure you have with a users table. Each user has an association to each existing object. Keep in mind sharing with other users in the event that you may want to allow one user to see another user's info.
My suggestion is provide an update to the app where after the first launch after updating it pushes their information to your MySQL database and inform the users that they can access their data via other methods now.
how many user to you expect? I would use only one database with a user table instead of hundreds/thousands of databases.
One table for all users (only with user info like id, email, password, etc).
Another table with comments (with user id and his comment), so that you can add as many comments per user as needed. If dates are related to comments put them on this table, else another table for dates as well.
I hava an android application which consists sqlite database in the assets folder.
In the DB I have several tables, which one of them is user data (which is updated over time by using the application - when the user installs the application this table is empty).
The other tables store data that I update.
The question is: when a user gets an updated version of my application (with sqlite database in the assets folder) from the market, I need to keep the data the user updated by using the application, but i do want to update the other tables (which consist my data).
What is the correct way to do it?
Thank You :)
Keep a version number for each change and implement the onUpgrade method for the possible combinations. See more in the javadoc for SQLiteOpenHelper
Since you said your tables are empty when the Database is first created, it shouldn't be necessary to add the Database from the /assets-folder.
Instead, you can use a SQLiteOpenHelper, which offers an onCreate()-method that can do the initial table-creation (an add some example data if necessary).
If you then update your app, you simply increase the Database-version and the onUpgrade()-method is called, where you can then perform the Database update.
See this other question: Run some code when user update my app
If your app comes with a huge Database and inserting entry's in the SQLiteOpenHelper isn't the right way to go, you can still check if the Database already exists and then do the updating (through the onUpgrade()-method) and keep the users data.