I am trying to update precompiled database in my app using a new database file downloaded from the internet. However when I download the file and replace the old one used by Realm with it, Realm still uses the old one till the next app restart. Unfortunately I still need to open the first DB to copy some data from it before downloading a new database. Is there a possiblity to force unload/reload the whole database?
I made a mistake and I accidentally created a new instance of Realm. The problem is that Realm instances are cached. I needed to use autoreleasepool {} and ensure that Realm is created only in the block.
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I'm currently using dropbox to backup the Realm database file and when i need to restore, i just delete the old file and than put the new one from dropbox in its place, but to work i need to restart the application.
So, i'm looking a way to avoid the app restart.
You could delete the current files the way Realm suggests in the docs: https://realm.io/docs/swift/latest/#deleting-realm-files
Then nil your current Realm, write the new file to the right location in your file system and create a new Realm instance. Then reload your UI to show the new data.
You'll also have to be careful that your code is not holding references to objects in the previous Realm before it gets deleted.
I have an issue with a realm database. I have an app which continues inserts data in the realm database. Now there is a scheduler which creates the a copy of zip file of this realm database in some interval of time. Now the problem is the zip file doesn't get the updated values. I am suspecting the realm's lock file might be preventing it. But I am not sure. Is there any way to get this thing done ?
As I understand you're making a backup of Realm file in some interval of time, right? So if you want to include all recent changes to backup you should make sure that all write transactions are committed before you make a copy.
You can also use -writeCopyToURL:encryptionKey:error: method to copy Realm to a temporary destination and then compress it if you need.
I have an app that uses a database of about 5000 entries.
This database is bundled in the app as a realm file.
I want to be able to update/add entries to this database regulary using REST and I think I have done it correctly - I just want to make sure.
This is how I have done it:
When the app is installed I copy the bundled database from the mainBundle to the Documents directory for read/write access. I then delete the database from the mainBundle.
When I update/add new entries to the database, they are pushed to the user using REST and inserted into the database located in the Documents directory.
When an update is released of the app, I make a check to see if the database already exists in the Documents folder - if it does I automatically remove the database in the mainBundle as it is not needed.
Am I on the right track with this? Is there a better way of doing it?
Appreciate any input!
Regards,
Erik
When I update/add new entries to the database, they are pushed to the user using REST and inserted into the database located in the Documents directory.
Technically, you can't push via REST. So I guess, you're either sending a background push notification to all installations or you're checking at application launch, whether there is a new version of the database available. That's at least what I would propose, but your requirements for getting new data out may vary.
When an update is released of the app, I make a check to see if the database already exists in the Documents folder - if it does I automatically remove the database in the mainBundle as it is not needed.
This doesn't work. The main bundle is the signed app bundle. If you would tamper the contents, that would prevent your app from launching. For that reason the access to it is limited by the OS to read-only. So this operation will always fail with an error. Instead you might properly just want to skip seeding the database from the main bundle.
I want my app to ship out with a pre-initialized DB.
In SQL, I would create a DB, do the necessary inserts, pg_dump to a file, and load from that file. I'm sure Realm has an equivalent method, but I'm not sure what it is and I couldn't find it in the documentation.
(Disclaimer: I work for Realm)
There's no pg_dump-like functionality in Realm, but you can distribute a pre-built Realm file along with your app and that'll work just fine. :)
At the moment, the best way to create a pre-made Realm file is to simply make a small sample app to generate and then populate the file, but we're working on adding that functionality to Realm Browser as well.
I am updating an old iOS app which used sqlite database. I changed the database structure adding columns to existing tables. Now, I am testing it on my device. If I clear my old app from iPad and then run this new updated version on it, it is working fine. But if I have the old version installed on ipad already and test this updated version, it is somehow using the old database instead of the one updated. Can some one help me why it is doing this?
My guess and to try and make a simple answer for you is this. It's likely you updated the database in the project file - which means when you run it, your new db will exist in the bundle. files in the bundle cannot be updated, so its common practice to copy the database out of the bundle and store it somewhere in the ios sandbox. I usually use the documents directory to keep it simple.
Most likely what is happening is that when you run it over a pervious install, it see's that the file is already copied over to the device so it does not touch it, however on new installs, it probably sees the database is missing so it copies it there and that is why on new installs it works fine but existing ones it does not.
Look in the app delegate or your root view controller for code that checks for the existing database and copies the database over if needed on startup.
If you need to update the database on existing installs, you would need to force the copy.
Beware though if you have data in the existing database not to overwrite it if its important. If important data is stored there, you have to either do a little shell game of getting the data and importing into the new database, or maybe a simpler way, is to run the database schema modification commands on the existing database so it is the same.
again, beware and make a copy of the local database file before you run those commands, just in case.
best of luck
In iOS, a SQLLite database is really just a file. When you used the old app, it created the schema in the database file. When you load the new app, the data remains, untouched. If you want to use the new schema, you will have to detect the old schema and update the existing data. I believe that there are documented ways to deal with this. Bryanmac's question reference seems to be a good place to start.
When you install a new version of your app, iOS actually installs it in a new directory and then copies the contents of the documents folder from the older version to the one in the newer version. If you want to just use your new db, the best way is to have this db renamed or stored in a different directory inside your app's document store.
Here's a relevant article on updating An sqlite CoreData backing store on iOS:
http://www.musicalgeometry.com/?p=1736