I tried update(Object), update(PreparedUpdate), executeRaw(String), updateRaw(String), and even tried directly using the helper class then using getData(String query). But my table's foreign field is still not updated. Any thoughts why this is happening?
I found out that I am using the method update(Object) on other methods while passing an outdated instance of the object I am trying to update. So once I use the actual update(PreparedUpdate) method, I am reverting the object back to its original state as some other method is using update(outdated Object)
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I need to return a value in my method that is to be downloaded from Firestore. Global variables are not working as I am aware of its asynchronous behavior. I found an Interface however that is not working and neither restructuring data flow is helping . I need to find a method to somehow return the value from this method as there are a lot of method calls dependent on this method so even passing the values through methods is not working out in my case.
A method named "Get Name" needs to return a string from Firestore
I am trying to use RoomDatabase in my Android App. And I am using LiveData to be able to refresh my changes automatically inside my fragment.
The first time I am running my app I am getting the data from the API, creating my RoomDatabase and storing my data.
The second time I run my app I want to check if my DataBase is not empty. But while using LiveData: the following code is returning null.
AppDatabase.getInstance(getContext()).getRecipeDao().getAllRecipes().getValue();
I have read that "if the response is an observable data type, such as Flowable or LiveData, Room watches all tables referenced in the query for invalidation".
How to check if my RoomDatabase has data or is empty?
So after implementing myself I found that you need to do a few things:
Make sure you have an Observer for changes to the LiveData
You need to call observeForever(Observer<T> observer) unless you are using a LiveCyclerOwner then use that instead with: observe (LifecycleOwner owner, Observer<T> observer)
Finally, there is an interesting note on getValue():
Returns the current value. Note that calling this method on a
background thread does not guarantee that the latest value set will be
received
So to reiterate, I think your approach does not work.
You will need to create some type of separate check rather than use a method that returns a LiveData class as noted since it does not guarantee the latest value set is received by calling getValue().
I would recommend something super simple in the end such as adding a new method to your Dao
#Query("SELECT * FROM recipes LIMIT 1")
Recipe getAnyRecipe();
and do this check looking for null to see if anything exists in the recipes table.
With realm 4.0, createQuery method from RealmQuery class is deprecated. Now, how can I encapsulate a query and pass it to another method?
realm.where(MyObject.class) returns a query.
But if you check the breaking changes, this is also mentioned there.
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.
I have the case that I operate on some object I got from greenDao and in some cases I have to revert the changes. I only got this to work with IdentityScope.None - with some IdentityScope I found no way to do that - even refresh() which sounded promising was not bringing back the data from the database. Is there any way to do this with a IdentityScope?
The refresh(entity) method of a DAO does reload all entity values from the database. However, it operates on a single entity, not on a tree of entities.
I'm targeting Android 2.2 and newer. This error was generated on a device running 4.x. I am using ORMLite 4.38 libraries.
I need to guarantee every record instance is unique for any number of devices. I was happy to see that ORMLite supports UUIDs as IDs. I've created a UUID - id abstract base class for my database record definitions. allowGeneratedIdInsert is the perfect solution. But this feature seems to cause an 'IllegalStateException: could not create data element in dao'. I tested by removing this annotation, and no issue. Put it back in...same issue. Put the base class stuff in one record definition...same issue.
LogCat also reports:
Caused by: java.sql.SQLException: Unable to run insert stmt on object - objectid: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxx
public abstract class UUIDDaoEnabled<T> extends BaseDaoEnabled<T, UUID> {
//allowGeneratedIdInsert allows us to set UUID when this device db didn't create it
#DatabaseField(generatedId = true, allowGeneratedIdInsert=true)
private UUID id;
...
public void setUUIDFromSerializedSource(SerializedModelBinaryInputStream stream, Dao<T, UUID> dao) throws SQLException { //only place we can set UUIDs
if(id == null)
dao.refresh((T)this);
if(id != null)
throw new SQLException("Trying to set UUID on existing object");
id = stream.getCurrentUUID();
}
}
I'll specialize like so:
#DatabaseTable()
public class Type extends UUIDDaoEnabled<Type> { ... }
I can't explain this from the documentation for allowGeneratedIdInsert and generatedId. In fact the documentation for alloeGeneratedIdInsert says it overrides the default behavior of generatedId. It also says
This only works if the database supports this behavior
Yet, I have read in other posts that ORMLite 4.25 (?) and newer supports this behavior on Android devices. So, either that's not entirely true. Or I'm doing something stupid...anyone???
UPDATE: after thinking about it for a minute, I realized that neither allowGeneratedIdInsert support, nor inheritance can be the root cause, because I instantiate other objects based on the same abstract class. What I can't figure out is why one particular class is causing the issue. The only unique thing about the offending record type (compared to other types that create) is it is a many in a one to many, and it contains several to manies. Could these properties, combined with allowGenereatedIdInsert, be the root issue? Rather, I should ask, has anyone seen this issue in this circumstance?
UPDATE: nevermind the question. I can use updateId(...) instead of allowGeneratedIdInsert.
So I'm not sure about this but it looks to me that you are trying to insert an element twice into a table with the same UUID id. The exception is saying there is a constraints failure:
IllegalStateException: Could not create data element in dao
at BaseForeignCollection.add(BaseForeignCollection.java:57)
...
Caused by: SQLiteConstraintException: error code 19: constraint failed
If you call foreignCollection.add(...); it does the same thing as dao.create(...); -- and you can't do both of these with the same object. If you have an existing object that has already been created by the DAO and you want to associate it with another object, you should do something like:
// associate this object with another
existingObject.setForeignField(...);
// now update it in the db
existingObjectDao.update(existingObject);
You can't add it to the foreignField's foreign collection.
I had a similar problem. But it was caused by using create instead createOrUpdate to save the object.
It is also important to uninstall the application before changing this to ensure that the database has been removed and will not keep the old behavior.
Edit: createOrUpdate is very time expensive. It's better use just create with great amounts of data.
Edit 2:It is also bether to use a TransactionManager.callInTransaction.