I have created a database using Room database library with name ImageDatabase, when I opened my Device File explorer in Android studio inside the database folder there were three files with names ImageDatabase, ImageDatabase-shm and ImageDatabase-wal. I wanted to know what are these files meant for? Any help would be great
Thanx All
The data in your database is contained in all three. The one with no extension is the main database. The others are the Write Ahead Log file (-wal) and the Shared Memory file (-shm). They are used by the underlying SQLite system to improve performance, and contain the latest changes to the main database until a checkpoint is done. You can find more information in the SQLite docs.
Your original database is ImageDatabase i.e name of database you give at the time of creation.
you can copy database and check the contain from here
upload your database in above link and you can verify it.
Related
I'm trying to make an android application capable of storing Strings into a database.db. I'm not sure on how to be able to take the database from /data/data folder somewhere else (i need to do it because i want the user to be able to move the db file from /data/data even if he/she doesn't have root permission). I tried a lot of different ways, but nothing worked fine. Can you help me?
I meant to ask how could I copy a dB file contained into /data/data folder to some other folder, and I found the way myself. I simply defined another constructor into my dB class, that I used to create a new dB file into the external storage path.
I am working on an android application on android studio, and I am using a sqlite database. The thing is, I want to change the structure of it, so do I just have to change it from DB Browser for SQLite, or I need to change it somewhere else ?
Because the code I am working on isn't mine, and I am just starting to lear android developement
An option is to change the internal structure of the database file from either DB Browser or command line on your computer and then copy it to your phone's storage when the App is running.
If you don't know the steps:
Step 1: Create a new database file from either command line or SQLite DB Browser with your required structure.
Step 2: Place the file in Assest directory in your Project folder. (Assest directory will be in the same folder as the 'res' and 'java' directories are)
Step 3: On Activity Start event, copy this empty database from Asset directory to your database directory which is generally located at /data/data/your.package/databases
Also you can query ALTER TABLE to add columns (as suggested in comments).
This explains the syntax for ALTER TABLE. It also explains other methods for implementing Schema Changes.
I want to create (export) my application into a Jar file to be portable.
How can i put my database contents with jar file?
For e.g for pictures, i put pictures folder beside my jar file, and it shows pictures correctly.
UPDATE
A peace of code to connect to database:
connection = DriverManager.getConnection("jdbc:mysql://localhost/Library", "root", "1234");
If you want to distribute a copy of your database with each copy of your application, I think using MySQL will be a bit complicated. You may want to look into using a database system designed to be embedded, such as SQLite, instead. A complete SQLite database is a single text file - you'd simply distribute your one mydatabase.db file along with the jar. See the examples at the above link.
There are two approaches you could use:
Approach 1
Do you really need to use database? If not, store your data on files in file system, that way you can easily export it with data.
Approach 2
Bundle the mysql installation directory in your jar / installer. Write a scripts which starts up both MySQL server and you application.
I was wondering if it is possible to easily add data to existing database in Eclipse. I have a database with about 1000 records, and I don't want to put them in by hand. (In my 'update'-activity.).
I've already tried to go to DDMS - data - data - (project name) - databases, and replace the file for another file with the same name. When I do that, I get an logcat error saying:
12-15 08:47:33.495: E/SQLiteLog(4564): (26) file is encrypted or is not a database
12-15 08:47:33.495: E/DefaultDatabaseErrorHandler(4564): Corruption reported by sqlite on database: /data/data/com.jacob.eindproject/databases/Voedsel
12-15 08:47:33.495: E/DefaultDatabaseErrorHandler(4564): deleting the database file: /data/data/com.jacob.eindproject/databases/Voedsel
I can 'pull a file from the device'. Can I add data then? Somebody has an idea?
Thank you all in advance,
Jacob
Unless you will be the only user of your app, pushing data to the device or emulator manually is useless. You cannot do that for thousands of users, if for no other reason than they are unlikely to mail you their phones so you can connect the USB cable and push the file.
If your objective is to ship an app that contains starter data for the app, I recommend SQLiteAssetHelper. This is a subclass of SQLiteOpenHelper that can automatically unpack a database bundled into your app when the database is first needed.
i'm trying to deal with Android since few weeks. And i'm now trying to access media databases files like photo, music, videos,settings,installed applications stored in the phone. What's these files paths?
I've already find contacts, bookmarks, sms files under "/data/data/com.android.providers" structure.
Can someone tell me the whole database structure?
your databases are under /data/data/[your package name]/databases/[your database name] although you should usually not be trying to access these
edit
adamcodes is right, corrected