android-room

问题 I want to change the location of the Android Room Database. I know that the database is inside of the files system, and I need to get root permissions, but I do not want to root my phone. The idea is change the database location to SD card, and can access it without root my phone 回答1: Just put the location path in the name of the database. I.e.: AppDatabase db = Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "database-name").build(); Put the router in database name. I.e.:

问题 I want to change the location of the Android Room Database. I know that the database is inside of the files system, and I need to get root permissions, but I do not want to root my phone. The idea is change the database location to SD card, and can access it without root my phone 回答1: Just put the location path in the name of the database. I.e.: AppDatabase db = Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "database-name").build(); Put the router in database name. I.e.:

问题 Apparently, Room is not able to handle MutableLiveData and we have to stick to LiveData as it returns the following error: error: Not sure how to convert a Cursor to this method's return type I created a "custom" MutableLiveData in my DB helper this way: class ProfileRepository @Inject internal constructor(private val profileDao: ProfileDao): ProfileRepo{ override fun insertProfile(profile: Profile){ profileDao.insertProfile(profile) } val mutableLiveData by lazy { MutableProfileLiveData() }

问题 So simply, the DAO @Query("DELETE FROM Things WHERE someIdOfTheThing IN (:listOfId)") abstract fun deleteThings(listOfId: MutableList<String>): Maybe<Int> usage, mDisposables.add(mThingsDao .deleteThings(listOfId) .subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) .subscribe({ ... }, { ... }) ) and error, // Cannot access database on the main thread since it may potentially lock the UI for a long period of time. The simple idea i was thinking is to specify subscribeOn

问题 Java POJO Object public class Section { @ColumnInfo(name="section_id") public int mSectionId; @ColumnInfo(name="section_name") public String mSectionName; public int getSectionId() { return mSectionId; } public void setSectionId(int mSectionId) { this.mSectionId = mSectionId; } public String getSectionName() { return mSectionName; } public void setSectionName(String mSectionName) { this.mSectionName = mSectionName; } } My Query method @Query("SELECT * FROM section") LiveData<List<Section>>

问题 Java POJO Object public class Section { @ColumnInfo(name="section_id") public int mSectionId; @ColumnInfo(name="section_name") public String mSectionName; public int getSectionId() { return mSectionId; } public void setSectionId(int mSectionId) { this.mSectionId = mSectionId; } public String getSectionName() { return mSectionName; } public void setSectionName(String mSectionName) { this.mSectionName = mSectionName; } } My Query method @Query("SELECT * FROM section") LiveData<List<Section>>

问题 I have a RecyclerView list of CardView items that is working properly. Upon creation of a new CardView that is inserted into the database, I would like to fire a Toast that informs the user that the CardView was successfully added and show the CardView number. The CardView number is the Id of the CardView item inserted into the database. The data is saved to the database when the user clicks on a Save button that fires onClickSave(). I set up an @Query in the Dao to get the MAX(cardId): Dao .

问题 I am trying to use Room in my application but I have a very complex query that makes a recursive and inner join between multiple tables here is my query, fun test(categoryId: Int): String { return "WITH CTE AS (SELECT id, parent_id, id AS CategoryID FROM categories WHERE parent_id= 0 UNION ALL SELECT t.id, t.parent_id, t.id|| ', ' || CategoryID AS CategoryID FROM categories t INNER JOIN CTE c ON t.parent_id = c.id) SELECT CTE.CategoryID FROM CTE where CTE.id= " + categoryId + " ORDER BY CTE

问题 I am trying to use Room in my application but I have a very complex query that makes a recursive and inner join between multiple tables here is my query, fun test(categoryId: Int): String { return "WITH CTE AS (SELECT id, parent_id, id AS CategoryID FROM categories WHERE parent_id= 0 UNION ALL SELECT t.id, t.parent_id, t.id|| ', ' || CategoryID AS CategoryID FROM categories t INNER JOIN CTE c ON t.parent_id = c.id) SELECT CTE.CategoryID FROM CTE where CTE.id= " + categoryId + " ORDER BY CTE

问题 The size of these libraries really increase the APK size. It’s almost 50% my App size, taking it to 16.3 MBs and when I analyze the APK, sqlcipher-lib alone is 48.9% of my apk size i.e 7.3MBs!!! Is there any workaround? Edit: Since this is a DB related issue and I believe it's good if the specified tags remain referenced for specificity during search by other developers. I think the answer below addresses it better in order to keep the conversation along specific topics 回答1: This section of