https://github.com/mathroule/room-delete-entity-sample
https://github.com/mathroule/room-delete-entity-sample
Last synced: about 1 year ago
JSON representation
- Host: GitHub
- URL: https://github.com/mathroule/room-delete-entity-sample
- Owner: mathroule
- License: mit
- Created: 2020-06-28T10:08:42.000Z (almost 6 years ago)
- Default Branch: master
- Last Pushed: 2020-06-28T12:06:09.000Z (almost 6 years ago)
- Last Synced: 2025-02-10T14:13:13.435Z (over 1 year ago)
- Language: Kotlin
- Size: 849 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Room delete entity sample
Sample project to showcase Room not deleting table when an entity is deleted during destructive migration.
To test the project, run master branch on a device. Then checkout one of the following branch and run it on the same device.
## Delete an entity
Branch [delete-book-entity](../../tree/delete-book-entity): `Book` entity has been removed from code. The `User` entity columns has been removed.
Room will not drop the table during the database destructive migration, it will lead to invalid foreign key constraint, since referenced column has been removed.
### Database schema version 1
### Database schema version 2
## Convert an entity to a database view
Branch [convert-book-entity-to-view](../../tree/convert-book-entity-to-view): `Book` entity has been transformed to a database view.
Room will not drop the table during the database destructive migration, but will try to delete the view. This lead to crash:
```
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mathroule.sample.room/com.mathroule.sample.room.MainActivity}: android.database.sqlite.SQLiteException: use DROP TABLE to delete table book (code 1 SQLITE_ERROR): , while compiling: DROP VIEW IF EXISTS `book`
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: android.database.sqlite.SQLiteException: use DROP TABLE to delete table book (code 1 SQLITE_ERROR): , while compiling: DROP VIEW IF EXISTS `book`
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:903)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:514)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteStatement.(SQLiteStatement.java:31)
at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1769)
at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1698)
at androidx.sqlite.db.framework.FrameworkSQLiteDatabase.execSQL(FrameworkSQLiteDatabase.java:242)
at com.mathroule.sample.room.database.SampleDatabase_Impl$1.dropAllTables(SampleDatabase_Impl.java:44)
at androidx.room.RoomOpenHelper.onUpgrade(RoomOpenHelper.java:114)
at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.onUpgrade(FrameworkSQLiteOpenHelper.java:124)
at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:398)
at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:298)
at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getWritableSupportDatabase(FrameworkSQLiteOpenHelper.java:92)
at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper.getWritableDatabase(FrameworkSQLiteOpenHelper.java:53)
at androidx.room.RoomDatabase.inTransaction(RoomDatabase.java:476)
at androidx.room.RoomDatabase.assertNotSuspendingTransaction(RoomDatabase.java:281)
at com.mathroule.sample.room.database.SampleDao_Impl.insert(SampleDao_Impl.java:39)
at com.mathroule.sample.room.MainActivity.onCreate(MainActivity.kt:19)
at android.app.Activity.performCreate(Activity.java:7136)
at android.app.Activity.performCreate(Activity.java:7127)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
```
## Generated sample database implementation
| Version 1 | Removed Book entity | Converted Book entity to view |
|-----------|---------------------|-------------------------------|
|  |  |  |