So I want to view my db structure through some db browser application, but for that I need to get mydatabase.db file from application installed on emulator. I found this file through Device File explorer under data/data/package.com/mydatabase.db but when I open this file in some sqlite editor it shows that its empty no tables etc.. I'm using Room database so I'm thinking maybe room does something to this file that I can't open it because under database folder there is three files mydatabase.db, mydatabase.db-shm, mydatabase.db-wal which I never seen before when I was using just sqlite and maybe there is other ways to check structure of my db?
The -wal file is for write-ahead logging (WAL), which Room 1.1.0 enables. Try copying all three files, then opening the .db file.
WAL is a standard SQLite feature and has been around for years, so most up-to-date SQLite clients should be able to handle it.
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In my android studio in data/data/com.../databases there are 3 files .db, shm.db , wal.db and when i save that .db file it is not showing any table.
While in my another mobile phone files there are only two .db, journal.db and it is showing the table and data when we save it .
i don't know why it is happening ???
If you want to check the database contents, you need to downlaod all those 3 files, store them together in a folder and then you would be able to check the contents of your db.
Your problem:
You are only trying to download the .db extension file. Thats why the issue is coming!
On later versions of Android SQLite Write Ahead logging is enabled by default.
Write ahead logging creates the Wal file, see https://sqlite.org/wal.html for more details.
When the database is closed then the contents of the Wal file will be committed to the main DB file, there is also automatic checkpointing and you can trigger it manually.
It is possible to disable it on a per connection basis, but if data does not get moved to the main db file when you application has been closed then your code is not closing the database properly.
I'm debugging an issue with an Android application that seems to stem from missing data in its SQLite database. When I open the database using Android Debug Database, the data is shown. However, when I save the SQLite file to my computer using Android Studio's Device File Explorer and then open it up with a SQLite client, the data is missing.
Using Room to manage the SQLite db, and used both TablePlus and DB Browser for SQLite to view the db on my computer.
Room uses write-ahead logging (WAL). Much of the time, this means that the SQLite database consists of three files:
Whatever you named the base file
One with .wal
One with .shm
You need to copy all three if you wish to use the database elsewhere (e.g., desktop SQLite browser, backup/restore).
I have accessed my sqlite file under data/data//databases/. Then I tried to open it in Android Studio. I selected SQL File as the file type, but Android Studio showed me a sequence of characters. Not a browser of sqlite file.
Is there any way to fix this? Can I open that sqlite database file under an application like 'DB Browser for SQLite', without saving that file under a folder and opening it from there?
No, you can't open sqlite files in Android Studio yet. Every day I do it this way:
stetho (http://facebook.github.io/stetho/) - powerful tool which allows browse tables and execute queries
or downloading DB file into my local file system (through adb or Device File Explorer) and open with SQLite Browser (https://sqlitebrowser.org/)
Please take a look at SQLite Administrator. It is a free software, you can open a database file, create tables, launch queries, etc. I use it quite often when I need to take a closer look at a SQLite db file.
You can try also this:
https://www.quora.com/How-do-I-see-database-tables-in-Android-Studio
I know about copying the database file solutoin,
How do I backup a database file to the SD card on Android?
Android backup/restore: how to backup an internal database?
Android backup/restore: how to backup an internal database?
in fact I was backing up my databases using this method, and up until a little while ago it was working perfectly.
until some multi-thread stuff made me use of enableWriteAheadLogging
now I have two more files near the database file with .db-wal and .db-shm extensions.
copying just the datbase file .db is not working as most of the times the file does not contain the latest database commits (which are available throw app itself) however when I copy three files together it seems to work fine (not quit sure, albeit)
as Sqlite people recommend, the best practice for backing up a sqlite database is to use backup api but can someone guid me on how I can use this api from inside an application, or even use sqlite .dump (How do I dump the data of some SQLite3 tables?) method from inside an app ?
So Which one is the best practice to back up a sqlite database from an android app?
1- Copy all the database-related files from the sandbox
2- Use sqlite Backup Api
3- Use sqlite .dump
4- any other method
The SQLite backup API is the only mechanism that works correctly with concurrent write accesses from other threads/processes. Which of course means that the Android database framework does not give you access to it.
If you are sure that there are not any active connections, you can just copy all files. (Leaving out journal or WAL files would lead to data corruption.) In the case of WAL, the -shm file
does not contain any permanent data and could be omitted.
The VACUUM INTO command introduced in SQLite version 3.27.0 (2019-02-07) can serve as an alternative to the backup API.
For testing, I wanted to manipulate the sqlite database for my Android app. I copied the database file to my laptop, edited the file with the Sqlite manager plugin for Firefox, and copied the file back to its directory.
I thought that would work, but the app crashes, because it can't open the database. The ownership and permissions of the file is like before.
Can someone explain to me why it won't work, or suggest how I could do instead?
1.Use Sqlite browser..download here
2.Pull your database to your computer..
3.Edit the database using sqlite browser
4.Delete the database from eclipse then push the edited database to your aplication Run the app to see the result