I am using realm in our iOS and Android app. For some reason i want to rename one of my realm object.
Initially we name the object Demo and now I want to change it to RealmDemo
In android we achieved it by using #RealmClass annotation
#RealmClass(name = "Demo")
open class RealmDemo : RealmObject() {
}
On iOS side i am not sure how exactly i can do similar as i did in android.
class RealmDemo: Object {
override static func className() -> String {
"Demo"
}
}
I tried above ^ but getting following error "Terminating app due to uncaught exception 'RLMException', reason: 'Object type 'Demo' not managed by the Realm'"
Two things.
First, You can name an object anything you want and change its name at any time.
HOWEVER, that's a destructive change, and Realm doesn't have any way to know the the newly named object 'is the same object' as the prior object.
How that's handled depends on what the use case is:
If this is a development situation, delete your local Realm files and run the app and the object with the new name will be created automatically.
If this is production then a migration block is needed (as on any platform) to migrate the data from the old object to the new one.
Secondly, The other important thing is the name of the object is now RealmDemo, whereas the prior object is Demo
class RealmDemo: Object {
so technically those are two separate objects. To Realm, you've abandoned the Demo object totally and that's a destructive change. Demo is still hanging around but is not referenced in your code so an error is thrown
On a possibly unrelated note, the className function references Demo
override static func className() -> String {
"Demo"
}
But the object name is RealmDemo.
It's not clear why the className function exists but it's not required or really needed. See the documentation for objects to get a feel for their structure - they may need a Primary Key
Seems like realm does not support className overriding for cocoa/ios.
https://github.com/realm/realm-cocoa/issues/2194
https://github.com/realm/realm-cocoa/issues/6624
Recently I have observed a large number of crashes for an app that I maintain when the Android P developer preview is used.
Diving (deep) into the project's code, I have found the problem method to be the following:
public static <T> T get(MatrixCursor cursor, int column) {
try {
cursor.moveToFirst();
Method get = MatrixCursor.class.getDeclaredMethod("get", int.class);
get.setAccessible(true);
return (T) get.invoke(cursor, column);
} catch (Exception e) {
throw new IllegalArgumentException("Android has changed the implementation of MatrixCursor?!");
}
}
From what I understand, this code is used to retrieve a custom object from the MatrixCursor directly, rather than a primitive type, byte array or String. There has previously been a private method within MatrixCursor that performs this internally, and it is this method that we access through reflection.
Needless to say, there's a number of issues with this approach. As far as I am aware, reflection to access private APIs is a feature that Android advises heavily against. Nevertheless, until the Android P preview, this seems to have been working as expected.
This leads me to raise the following questions:
Has MatrixCursor's implementation changed or is reflection totally deprecated as of Android P?
Sadly, I am not 100% clued up on what alternatives I have to avoid this issue. Any suggestions for that are greatly appreciated, is there a Cursor that can be used to store custom objects?
Yes, something has changed.
No, the underlying implementation of MatrixCursor has likely not changed.
What has changed is that Android P is introducing restrictions on non-public members of SDK classes. Attempting to use private fields or methods on SDK classes (whether by direct invocation, reflection, or JNI) will result in a crash.
If you run the code in question on a device running P and look at the logcat output, you should see a message similar to this:
Accessing hidden field Landroid/os/Message;->flags:I (light greylist, JNI)
I highly encourage you to fully read the linked documentation on these restrictions for the full context and for more information on how you can handle it.
One option (which you should do ASAP if needed!) is to file a bug so the Android team knows that this is a method you use and does not have a public alternative. If you do this before the release of Android P, there is a much better likelihood that the team will either create a public alternative for this method or allow you to continue to access that method in P.
I'm currently running Realm Version 0.82.0 in one of my Android projects. I didn't touch Realm for quite some time, until I recently noticed that they went up until version 2.0.2 in the meantime. I would like to upgrade my version of Realm, unfortunately, I don't know if the upgrade from my old version to the current release will be working or breaking my code.
I'm especially concerned of migrations, since the API for migrations seemed to have changed a bit since my code, and I'm unsure if my migrations will break if I just update my version. Unfortunately, there is no documentation about upgrading Realm version available on their webpage.
Does anyone have any experience with upgrading Realm, especiall a version increase over two major versions?
The list of breaking changes is available in the CHANGELOG.MD on their Github.
However, it's worth noting that there were quite a few breaking changes on the road, especially noting 0.89.0.
From 0.82.0 to 5.1.0 is the following (which is the most stable version at the moment):
0.82.0:
BREAKING CHANGE: Fields with annotation #PrimaryKey are indexed automatically now. Older schemas require a migration.
(0.82.2 was most stable here, but it didn't work on Blackberry devices. The first stable version to use on Blackberry was 0.87.2.)
In 0.86.0+, you can add an index to the annotated field using
#Override
public void migrate(final DynamicRealm realm, long oldVersion, long newVersion) {
RealmSchema schema = realm.getSchema();
// version check and stuff
RealmObjectSchema personSchema = schema.get("Person");
personSchema.addIndex("fieldName");
0.83:
BREAKING CHANGE: Database file format update. The Realm file created by this version cannot be used by previous versions of Realm.
BREAKING CHANGE: Removed deprecated methods and constructors from the Realm class.
BREAKING CHANGE: Introduced boxed types Boolean, Byte, Short, Integer, Long, Float and Double. Added null support. Introduced annotation #Required to indicate a field is not nullable. String, Date and byte[] became nullable by default which means a RealmMigrationNeededException will be thrown if an previous version of a Realm file is opened.
Oh boy, this is a nice one. NULL support.
Boxed types for primitives became available. Boxed types are nullable by default. All String, Date, and byte[] must be annotated with #Required, or schema.setNullable("fieldName", nullability) and make them all nullable.
0.84.0:
Async queries were added. Nothing new here in terms of schema.
0.85.0:
BREAKING CHANGE: Removed RealmEncryptionNotSupportedException since the encryption implementation changed in Realm's underlying storage engine. Encryption is now supported on all devices.
BREAKING CHANGE: Realm.executeTransaction() now directly throws any RuntimeException instead of wrapping it in a RealmException (#1682).
BREAKING CHANGE: RealmQuery.isNull() and RealmQuery.isNotNull() now throw IllegalArgumentException instead of RealmError if the fieldname is a linked field and the last element is a link (#1693).
Nothing important here yet, although:
Setters in managed object for RealmObject and RealmList now throw IllegalArgumentException if the value contains an invalid (unmanaged, removed, closed, from different Realm) object (#1749).
This one is an interesting one. Previously it just failed, so this is for the best. But it is Realm's largest limitation, too.
0.86.0:
BREAKING CHANGE: The Migration API has been replaced with a new API.
BREAKING CHANGE: RealmResults.SORT_ORDER_ASCENDING and RealmResults.SORT_ORDER_DESCENDING constants have been replaced by Sort.ASCENDING and Sort.DESCENDING enums.
BREAKING CHANGE: RealmQuery.CASE_SENSITIVE and RealmQuery.CASE_INSENSITIVE constants have been replaced by Case.SENSITIVE and Case.INSENSITIVE enums.
BREAKING CHANGE: Realm.addChangeListener, RealmObject.addChangeListener and RealmResults.addChangeListener hold a strong reference to the listener, you should unregister the listener to avoid memory leaks.
BREAKING CHANGE: Removed deprecated methods RealmQuery.minimum{Int,Float,Double}, RealmQuery.maximum{Int,Float,Double}, RealmQuery.sum{Int,Float,Double} and RealmQuery.average{Int,Float,Double}. Use RealmQuery.min(), RealmQuery.max(), RealmQuery.sum() and RealmQuery.average() instead.
BREAKING CHANGE: Removed RealmConfiguration.getSchemaMediator() which is public by mistake. And RealmConfiguration.getRealmObjectClasses() is added as an alternative in order to obtain the set of model classes (#1797).
BREAKING CHANGE: Realm.addChangeListener, RealmObject.addChangeListener and RealmResults.addChangeListener will throw an IllegalStateException when invoked on a non-Looper thread. This is to prevent registering listeners that will not be invoked.
Added new Dynamic API using DynamicRealm and DynamicRealmObject.
Added Realm.getSchema() and DynamicRealm.getSchema().
The new Migration API, using DynamicRealm instead of Realm.getTable().
Some stuff were renamed, and you ought to unregister your change listeners if your result set is still valid. But it's worth noting that you should still retain a field variable to your RealmResults, because Realm's Context only has a weak reference to it.
0.87.0:
RX support. Nothing important.
0.87.2:
Removed explicit GC call when committing a transaction (#1925).
Finally, Realm got stable again! :)
0.88.0:
Breaking changes
Realm has now to be installed as a Gradle plugin.
DynamicRealm.executeTransaction() now directly throws any RuntimeException instead of wrapping it in a RealmException (#1682).
DynamicRealm.executeTransaction() now throws IllegalArgumentException instead of silently accepting a null Transaction object.
String setters now throw IllegalArgumentException instead of RealmError for invalid surrogates.
DynamicRealm.distinct()/distinctAsync() and Realm.distinct()/distinctAsync() now throw IllegalArgumentException instead of UnsupportedOperationException for invalid type or unindexed field.
All thread local change listeners are now delayed until the next Looper event instead of being triggered when committing.
Removed RealmConfiguration.getSchemaMediator() from public API which was deprecated in 0.86.0. Please use RealmConfiguration.getRealmObjectClasses() to obtain the set of model classes (#1797).
Realm.migrateRealm() throws a FileNotFoundException if the Realm file doesn't exist.
It is now required to unsubscribe from all Realm RxJava observables in order to fully close the Realm (#2357).
Welp. It's an AAR now. You have to add to classpath and run it with apply plugin: 'realm-android' instead of compile ... dependency.
Change listeners are only called on the next event loop, instead of immediately after commit. I'm.. honestly not entirely sure of the ramifications of this, but it means change listeners don't work on background threads. Only on looper threads (primarily the UI thread).
Enhancements
Support for custom methods, custom logic in accessors, custom accessor names, interface implementation and public fields in Realm objects (#909).
Improved .so loading by using ReLinker.
This is quite necessary though, so I wouldn't want to get stuck on 0.87.5 for sure.
0.89.0:
Breaking changes
#PrimaryKey field value can now be null for String, Byte, Short, Integer, and Long types. Older Realms should be migrated, using RealmObjectSchema.setNullable(), or by adding the #Required annotation. (#2515).
RealmResults.clear() now throws UnsupportedOperationException. Use RealmResults.deleteAllFromRealm() instead.
RealmResults.remove(int) now throws UnsupportedOperationException. Use RealmResults.deleteFromRealm(int) instead.
RealmResults.sort() and RealmList.sort() now return the sorted result instead of sorting in-place.
RealmList.first() and RealmList.last() now throw ArrayIndexOutOfBoundsException if RealmList is empty.
Removed deprecated method Realm.getTable() from public API.
Realm.refresh() and DynamicRealm.refresh() on a Looper no longer have any effect. RealmObject and RealmResults are always updated on the next event loop.
Okay, this one is the most messy one.
1.) you must add #Required annotation for #PrimaryKey annotated fields, because null is a valid primary key value.
2.) realm.refresh() no longer works. It will be removed anyways. Here's a workaround for 1.1.1 though, should be used only on background threads. It is available in Realm 3.2 again, though.
3.) getTable() is removed. Don't use it. Use the new migration API.
4.) realmResults.sort() returns a new RealmResults, which needs to have the change listener appended to it as well. I think it's unreliable, so I'd just use findAllSorted() instead.
5.) You might not think much of it, but
RealmObject and RealmResults are always updated on the next event loop. (NOTE: THIS IS NO LONGER TRUE SINCE REALM 3.1+ WHERE CHANGE LISTENERS ARE CALLED AGAIN ON commitTransaction())
This literally meant that RealmResults were only updated when the event loop occured, it was NOT immediately updated when you call realm.commitTransaction(). This also means that on background threads, the RealmResults did NOT update when you commitTransaction(), you had to requery them.
The RealmResults are only known to be updated after the appended RealmChangeListener is called. In 1.1.1, when the RealmChangeListener is called, all Results had been updated.
This change however also changed iteration behavior in transactions. In transactions, you always saw the newest version. This meant that a query was re-evaluated as you were iterating on it, and modifying elements. (THIS IS ALSO THE CASE SINCE REALM 3.0)
Example, previously this was valid code:
RealmResults<Stuff> stuffs = realm.where(Stuff.class).equalTo("something", false).findAll();
while(!stuffs.isEmpty()) {
stuffs.get(0).setSomething(true);
}
// you end up here because stuffs will be empty
// because of live auto-updates in transactions
However, this will no longer work. For me, this caused issues because I iterated sometimes like this
RealmResults<Stuff> stuffs = realm.where(Stuff.class).equalTo("something", false).findAll();
for(int i = 0; i < stuffs.size(); i++) {
stuffs.get(i--).setSomething(true);
}
// I end up here because of live auto-updates
This is a problem, because the stuffs will no longer change. I had to do a search for -- in my code and fix all iteration like this.
The official workaround used to be this:
RealmResults<Stuff> stuffs = realm.where(Stuff.class).equalTo("something", false).findAll();
for(int i = stuffs.size()-1; i >= 0; i--) {
stuffs.get(i).setSomething(true);
}
// I end up here because of normal iteration
This would still work fine in 0.89.0.
Since 0.89.0, this is valid code too (and in 3.0.0+, this automatically creates a snapshot collection):
RealmResults<Stuff> stuffs = realm.where(Stuff.class).equalTo("something", false).findAll();
for(Stuff stuff : stuffs) {
stuff.setSomething(true);
}
The elements in the results still get invalidated though, but the results themselves don't change. (This is the same for snapshot collections as well in Realm 3.0.0+).
0.90.0:
Breaking changes
RealmChangeListener provides the changed object/Realm/collection as well (#1594).
All JSON methods on Realm now only wraps JSONException in RealmException. All other Exceptions are thrown as they are.
Marked all methods on RealmObject and all public classes final (#1594).
Removed BaseRealm from the public API.
Removed HandlerController from the public API.
Removed constructor of RealmAsyncTask from the public API (#1594).
RealmBaseAdapter has been moved to its own GitHub repository: https://github.com/realm/realm-android-adapters
File format of Realm files is changed. Files will be automatically upgraded but opening a Realm file with older versions of Realm is not possible.
So RealmBaseAdapter is now in realm-android-adapters, for 1.1.1 of Realm, use 1.3.0. Also adds RealmRecyclerViewAdapter. For 3.5.0, use 2.0.0 or newer.
RealmChangeListeners got an element parameter. Yay.
Also, Date now has milisecond precision.
0.91.0:
Breaking changes
Removed all #Deprecated methods.
Calling Realm.setAutoRefresh() or DynamicRealm.setAutoRefresh() from non-Looper thread throws IllegalStateException even if the autoRefresh is false (#2820).
Deprecated a lot of methods in 0.90.0, so
Breaking Changes:
Realm.allObjects*(). Use Realm.where(clazz).findAll*() instead.
Realm.distinct*(). Use Realm.where(clazz).distinct*() instead.
DynamicRealm.allObjects*(). Use DynamicRealm.where(className).findAll*() instead.
DynamicRealm.distinct*(). Use DynamicRealm.where(className).distinct*() instead.
Realm.allObjectsSorted(field, sort, field, sort, field, sort). Use RealmQuery.findAllSorted(field[], sort[])` instead.
RealmQuery.findAllSorted(field, sort, field, sort, field, sort). Use RealmQuery.findAllSorted(field[], sort[])` instead.
RealmQuery.findAllSortedAsync(field, sort, field, sort, field, sort). Use RealmQuery.findAllSortedAsync(field[], sort[])` instead.
RealmConfiguration.setModules(). Use RealmConfiguration.modules() instead.
Realm.refresh() and DynamicRealm.refresh(). Use Realm.waitForChange()/stopWaitForChange() or DynamicRealm.waitForChange()/stopWaitForChange() instead.
waitForChange() doesn't really work as people would intend to use it, so here's a workaround for 1.1.1 to 3.1.4 though, should be used only on background threads. refresh() will be re-added in 3.2.0.
Also, at some point Realm.getInstance(Context) was removed, use Realm.getInstance(new RealmConfiguration.Builder(Context).build()) instead.
After that, 1.0.0 came, so it's pretty much just that.
By the way, in 1.1.0, insertOrUpdate() was added which is faster than copyToRealmOrUpdate(), and doesn't return a proxy.
2.0.2:
Primary keys are immutable on managed objects, once it's set, it cannot be changed, and it throws an exception if you try. Also, use realm.createObject(clazz, primaryKeyValue) if you use createObject() to create objects.
You must call Realm.init(Context) at some point.
Configuration Builder no longer receives Context.
armeabi is no longer supported. (only v7a and the others)
No breaking changes until 3.0.0, but a ton of bugfixes.
3.0.0:
RealmResults.distinct() returns a new RealmResults object instead of filtering on the original object (#2947).
RealmResults is auto-updated continuously. Any transaction on the current thread which may have an impact on the order or elements of the RealmResults will change the RealmResults immediately instead of change it in the next event loop. The standard RealmResults.iterator() will continue to work as normal, which means that you can still delete or modify elements without impacting the iterator. The same is not true for simple for-loops. In some cases a simple for-loop will not work (https://realm.io/docs/java/3.0.0/api/io/realm/OrderedRealmCollection.html#loops), and you must use the new createSnapshot() method.
RealmChangeListener on RealmObject will now also be triggered when the object is deleted. Use RealmObject.isValid() to check this state(#3138).
RealmObject.asObservable() will now emit the object when it is deleted. Use RealmObject.isValid() to check this state (#3138).
Removed deprecated classes Logger and AndroidLogger (#4050).
Due to the Realm ObjectStore Results integration, RealmResults is live again in transactions, just like back in 0.88.3 and before.
So simple for loops (indexing with for(int i = 0; ...) is prone to break -
meaning you either need to reverse iterate them, or create a snapshot collection first.
OrderedRealmCollection<Thing> snapshot = results.createSnapshot();
for(int i = 0; i < snapshot.size(); i++) { ...
Also, RealmObject change listener will now also emit on deletion, you need to check for isValid() in the change listener. This is so that you can update the UI if the object has been deleted in the background.
3.1.0:
Updated file format of Realm files. Existing Realm files will automatically be migrated to the new format when they are opened, but older versions of Realm cannot open these files.
Nothing to do here, but it's worth a mention.
3.2.0-3.2.1:
Nothing to do here, except update proguard, because there was a bug introduced here. Added proguard section.
3.3.0: (and 3.3.1)
Nothing to do here, the bug was fixed which caused the Proguard problem in 3.2.0.
3.4.0:
Nothing to do here, although it's worth looking at the new #LinkingObjects API for inverse relationships.
In fact, it is recommended to replace bi-directional links with uni-directional link + inverse relationship.
3.5.0:
Breaking Changes
An IllegalStateException will be thrown if the given RealmModule doesn't include all required model classes (#3398).
If you haven't specified all RealmObjects in the modules() (in case you use multiple modules instead of just the default, for example RealmObjects from a library project), then you need to make sure you actually provide all RealmObjects that are part of the schema in your modules.
Previously it silently added them even if they were not in the modules, now that is not the case.
4.0.0:
Breaking Changes
The internal file format has been upgraded. Opening an older Realm
will upgrade the file automatically, but older versions of Realm will
no longer be able to read the file.
[ObjectServer] Updated protocol version to 22 which is only compatible
with Realm Object Server >= 2.0.0.
[ObjectServer] Removed deprecated
APIs SyncUser.retrieveUser() and SyncUser.retrieveUserAsync(). Use
SyncUser.retrieveInfoForUser() and retrieveInfoForUserAsync() instead.
[ObjectServer] SyncUser.Callback now accepts a generic parameter
indicating type of object returned when onSuccess is called.
[ObjectServer] Renamed SyncUser.getAccessToken to
SyncUser.getRefreshToken.
[ObjectServer] Removed deprecated API
SyncUser.getManagementRealm().
Calling distinct() on a sorted
RealmResults no longer clears any sorting defined (#3503).
Relaxed
upper bound of type parameter of RealmList, RealmQuery, RealmResults,
RealmCollection, OrderedRealmCollection and
OrderedRealmCollectionSnapshot.
Realm has upgraded its RxJava1 support
to RxJava2 (#3497) Realm.asObservable() has been renamed to
Realm.asFlowable(). RealmList.asObservable() has been renamed to
RealmList.asFlowable(). RealmResults.asObservable() has been renamed
to RealmResults.asFlowable(). RealmObject.asObservable() has been
renamed to RealmObject.asFlowable(). RxObservableFactory now return
RxJava2 types instead of RxJava1 types.
Removed deprecated APIs
RealmSchema.close() and RealmObjectSchema.close(). Those don't have to
be called anymore.
Removed deprecated API
RealmResults.removeChangeListeners(). Use
RealmResults.removeAllChangeListeners() instead.
Removed deprecated
API RealmObject.removeChangeListeners(). Use
RealmObject.removeAllChangeListeners() instead.
Removed
UNSUPPORTED_TABLE, UNSUPPORTED_MIXED and UNSUPPORTED_DATE from
RealmFieldType.
Removed deprecated API
RealmResults.distinct()/RealmResults.distinctAsync(). Use
RealmQuery.distinct()/RealmQuery.distinctAsync() instead.
RealmQuery.createQuery(Realm, Class),
RealmQuery.createDynamicQuery(DynamicRealm, String),
RealmQuery.createQueryFromResult(RealmResults) and
RealmQuery.createQueryFromList(RealmList) have been removed. Use
Realm.where(Class), DynamicRealm.where(String), RealmResults.where()
and RealmList.where() instead.
So Rx1 support was replaced with Rx2 support, and removeChangeListeners() was renamed to removeAllChangeListeners().
Most other things only affect sync Realms, and from this point it is possible to use RealmList<String>, RealmList<Date>, and RealmList<Integer> as part of the Realm schema. Querying them is not yet supported, and they are not filled out by create*FromJson methods.
4.3.1:
Deprecated
RealmQuery.findAllSorted() and RealmQuery.findAllSortedAsync()
variants in favor of predicate RealmQuery.sort().findAll().
RealmQuery.distinct() and RealmQuery.distinctAsync() variants in favor
of predicate RealmQuery.distinctValues().findAll()
Instead of using realm.where(Blah.class).distinct("something") or realm.where(Blah.class).findAllSorted("something"), you can now do
realm.where(Blah.class)
.distinctValues("something") // subject to change to `distinct()`
.sort("something") // hopefully will change to `sorted()`? // nope, it's `sort`
.findAll();
5.0.0:
Renamed RealmQuery.distinctValues() to RealmQuery.distinct()
Removed previously deprecated RealmQuery.findAllSorted(), RealmQuery.findAllSortedAsync() RealmQuery.distinct() andRealmQuery.distinctAsync()`.
The OrderedCollectionChangeSet parameter in OrderedRealmCollectionChangeListener.onChange() is no longer nullable. Use changeSet.getState() instead (#5619).
So this means that realm.where(...).findAllSorted("field") should be realm.where(...).sort("field").findAll().
Also comes that OrderedRealmCollectionChangeListener used to send null as the initial change set, now that is no longer the case, and == null should be replaced with .getState() == OrderedCollectionChangeSet.State.INITIAL. This also means that you need to use realm-android-adapters 3.0.0 or newer with Realm 5.0+.
Also, if you relied on the names of __RealmProxy classes: they are named by their fully qualified name, including packages, like my_package_SomeObjectRealmProxy.
PROGUARD RULES
#realm older than 0.84.1
-keepnames public class * extends io.realm.RealmObject
-keep #io.realm.annotations.RealmModule class *
-keep class io.realm.** { *; }
-dontwarn javax.**
-dontwarn io.realm.**
#realm 0.84.1+ and older than 1.0.0
-keep class io.realm.annotations.RealmModule
-keep #io.realm.annotations.RealmModule class *
-keep class io.realm.internal.Keep
-keep #io.realm.internal.Keep class *
-dontwarn javax.**
-dontwarn io.realm.**
#realm 0.89.0+ and older than 1.0.0
-keep class io.realm.RealmCollection
-keep class io.realm.OrderedRealmCollection
#realm 3.2.0 and 3.2.1
-keepnames public class * extends io.realm.RealmObject
The main upgrade to Realm from 4+ to 5+ needs to change from:
realm.where(example.class)
.findAllSorted("field")
To:
realm.where(example.class)
.sort("field")
.findAll();
I am trying to implement DBFlow for the first time and I think I might just not get it. I am not an advanced Android developer, but I have created a few apps. In the past, I would just create a "database" object that extends SQLiteOpenHelper, then override the callback methods.
In onCreate, once all of the tables have been created, I would populate any lookup data with a hard-coded SQL string: db.execSQL(Interface.INSERT_SQL_STRING);. Because I'm lazy, in onUpgrade() and onDowngrade(), I would just DROP the tables and call onCreate(db);.
I have read through the migrations documentation, which not only seems to be outdated syntactically because "database =" has been changed to "databaseName =" in the annotation, but also makes no mention of migrating from no database to version "initial". I found an issue that claims that migration 0 can be used for this purpose, but I cannot get any migrations to work at this point.
Any help would be greatly appreciated. The project is # Github.
The answer below is correct, but I believe that this Answer and Question will soon be "deprecated" along with most third-part ORMs. Google's new Room Persistence Library (Yigit's Talk) will be preferred in most cases. Although DBFlow will certainly carry on (Thank You Andrew) in many projects, here is a good place to re-direct people to the newest "best practice" because this particular question was/is geared for those new to DBFlow.
The correct way to initialize the database (akin to the SQLiteOpenHelper's onCreate(db) callback is to create a Migration object that extends BaseMigration with the version=0, then add the following to the onCreate() in the Application class (or wherever you are doing the DBFlow initialization):
FlowManager.init(new FlowConfig.Builder(this).build());
FlowManager.getDatabase(BracketsDatabase.NAME).getWritableDatabase();
In the Migration Class, you override the migrate() and then you can use the Transaction manager to initialize lookup data or other initial database content.
Migration Class:
#Migration(version = 0, database = BracketsDatabase.class)
public class DatabaseInit extends BaseMigration {
private static final String TAG = "classTag";
#Override
public void migrate(DatabaseWrapper database) {
Log.d(TAG, "Init Data...");
populateMethodOne();
populateMethodTwo();
populateMethodThree();
Log.d(TAG, "Data Initialized");
}
To populate the data, use your models to create the records and the Transaction Manager to save the models via FlowManager.getDatabase(AppDatabase.class).getTransactionManager()
.getSaveQueue().addAll(models);
To initialize data in DBFlow all you have to do is create a class for your object models that extends BaseModel and use the #Table annotation for the class.
Then create some objects of that class and call .save() on them.
You can check the examples in the library's documentation.
So I have a custom subclass of OrmLiteSqliteOpenHelper. I want to use the ObjectCache interface to make sure I have identity-mapping from DB rows to in-memory objects, so I override getDao(...) as:
#Override
public <D extends Dao<T, ?>, T> D getDao(Class<T> arg0) throws SQLException {
D dao = super.getDao(arg0);
if (dao.getObjectCache() == null && !UNCACHED_CLASSES.contains(arg0))
dao.setObjectCache(InsightOpenHelperManager.sharedCache());
return dao;
}
My understanding is that super.getDao(Class<T> clazz) is basically doing a call to DaoManager.createDao(this.getConnectionSource(),clazz) behind the scenes, which should find a cached DAO if one exists. However...
final DatabaseHelper helpy = CustomOpenHelperManager.getHelper(StoreDatabaseHelper.class);
final CoreDao<Store, Integer> storeDao = helpy.getDao(Store.class);
DaoManager.registerDao(helpy.getConnectionSource(), storeDao);
final Dao<Store,Integer> testDao = DaoManager.createDao(helpy.getConnectionSource(), Store.class);
I would expect that (even w/o the registerDao(...) call) storeDao and testDao should be references to the same object. I see this in the Eclipse debugger, however:
Also, testDao's object cache is null.
Am I doing something wrong here? Is this a bug?
I do have a custom helper manager, but only because I needed to manage several databases. It's just a hashmap of Class<? extends DatabaseHelper> keys to instances.
The reason I need my DAO cached is that I have several foreign collections that are eager and are being loaded by internally-generated DAOs that are not using my global cache and thus are being re-created independently for each collection.
As I was writing this up, I thought I could just have my overridden helpy.getDao(...) call through to DaoManager.createDao(...), but that results in the same thing: I still get a different DAO on the second call to createDao(...). This seems to me to be totally against the docs for DaoManager.
First, I thought it looked like registerDao(...) may be the culprit:
public static synchronized void registerDao(ConnectionSource connectionSource, Dao<?, ?> dao) {
if (connectionSource == null) {
throw new IllegalArgumentException("connectionSource argument cannot be null");
}
if (dao instanceof BaseDaoImpl) {
DatabaseTableConfig<?> tableConfig = ((BaseDaoImpl<?, ?>) dao).getTableConfig();
if (tableConfig != null) {
tableMap.put(new TableConfigConnectionSource(connectionSource, tableConfig), dao);
return;
}
}
classMap.put(new ClassConnectionSource(connectionSource, dao.getDataClass()), dao);
}
That return on line 230 of the source for DaoManager prevents the classMap from being updated (since I'm using the pregenerated config files?). When my code hits the second create call, it looks at the classMap first, and somehow (against my better understanding) finds a different copy of the DAO living there. Which is super weird, because stepping through the first create, I watched the classMap be initialized.
But where would a second DAO possibly come from?
Looking forward to Gray's insight! :-)
As #Ben mentioned, there is some internal DAO creation which is screwing things up but I think he may have uncovered a bug.
Under Android, ORMLite tries to use some magic reflection to build the DAOs given the horrible reflection performance under all but the most recent Android OS versions. Whenever the user asks for the DAO for class Store (for example), the magic reflection fu is creating one DAO but internally it is using another one. I've created the follow bug:
https://sourceforge.net/tracker/?func=detail&aid=3487674&group_id=297653&atid=1255989
I changed the way the DAOs get created to do a better job of using the reflection output. The changes were pushed out in the 4.34. This release revamps (and simplifies) the internal DAO creation and caching. It should fix the issue.
http://ormlite.com/releases/
Just kidding. Looks like what may be happening is that my Store object DAO initialization is creating DAO's for foreign connections (that I set to foreignAutoRefresh) and then recursively creating another DAO for itself (since the DAO creation that started this has not completed, and thus has yet to be registered w/ the DaoManager).
Looks like this has to do w/ the recursion noted in BaseDaoImpl.initialize().
I'm getting Inception flashbacks just looking at this.