How do I update the Room version in adnroid?

Question

My Room Database is as follows

@Database(entities = [UserEntity::class], version = 6)
abstract class RoomDB : RoomDatabase() {
    abstract fun getDao(): RoomDao

    companion object {
        private var INSTANCE: RoomDB? = null

        val MIGRATION_5_6 = object : Migration(5, 6) {
            override fun migrate(database: SupportSQLiteDatabase) {
                database.execSQL(
                    "CREATE TABLE my_table_new (" +
                            "id INTEGER NOT NULL, " +
                            "name TEXT, " +
                            "age INTEGER NOT NULL, " +
                            "PRIMARY KEY(id))"
                )

                database.execSQL("INSERT INTO my_table_new (id, name, age) SELECT id, name, 0 FROM my_table")

                database.execSQL("DROP TABLE my_table")

                database.execSQL("ALTER TABLE my_table_new RENAME TO my_table")
            }
        }

        fun getInstance(context: Context): RoomDB {
            if (INSTANCE == null) {
                synchronized(RoomDB::class) {
                    INSTANCE = Room.databaseBuilder(
                        context.applicationContext,
                        RoomDB::class.java,
                        "user.db"
                    )
                        .addMigrations(MIGRATION_5_6)
                        .build()
                }
            }

            return INSTANCE!!
        }

    }
}

The previous version was 5, this time the upgraded version is 6. There was no age column in version 5, but it was newly added in version 6. So if you look at the INSERT INTO statement, you can see that the number 0 is forcibly inserted. As you can see from the code, we have also written the MIGRATION code. Dao is:

@Dao
interface RoomDao {
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    fun insert(entity: UserEntity)

    @Delete
    fun delete(entity: UserEntity)

    @Query("SELECT * FROM my_table")
    fun getUser(): List

    @Query("DELETE FROM my_table")
    fun deleteAll()
}

Entity looks like this:

@Entity(tableName = "my_table")
data class UserEntity(
    @ColumnInfo(name = "id")
    @PrimaryKey var id: Int,
    @ColumnInfo(name = "name")
    var name: String,
    @ColumnInfo(name = "age")
    var age: Int
)

When I call getUser() here, I get the following Exception.

java.lang.IllegalStateException: Room cannot verify the data integrity. Looks like you've changed schema but forgot to update the version number. You can simply fix this by increasing the version number.

How on earth should I upgrade the Room version? Is there anything I am doing wrong?

How do I update the Room version in adnroid?

Answers (1)

Related Questions