I am creating my very first app in Objective-C, which needs to contain static database in app itself. Idea is that even without internet connection user can use the database and search for the required info.
As I understood from what I read using Core Data and SQLite will not be very good in my case or I need to create a database separately and use it with Core Data or something like this.
Data in database will be only strings.
Can You please advise what will be the best way in my case?
Thanks
There is no problem in using Core Data, or you can simply use a plist file to store your 700 e-additives.
Related
I am going to display list of cities and countries. I have to get it from server using web service. but city and country are not changed every time. so we don't need to call that web service every time. so we can store all the information locally. what is the best way to handle this situation?
Yes you are right we don't need to call web service every time. You can use coredata in this situation. Using coredata you can manage all data locally and retrive back from coredata.
Core Data is the best one to use for non-trivial data storage. It can reduce the memory overhead of your app, increase responsiveness, and save you from writing a lot of boilerplate code.
Refer this link : http://www.raywenderlich.com/934/core-data-tutorial-for-ios-getting-started
You can do this in several ways
you can use nsurl session caching
store data in local db (coredata or sqlite) http://www.raywenderlich.com/934/core-data-tutorial-for-ios-getting-started
For simple data you should use NSUserDefaults
use plist file http://www.theappcodeblog.com/?tag=ios-saving-data-to-plist-tutorial
http://code.tutsplus.com/tutorials/ios-sdk-working-with-nsuserdefaults--mobile-6039
please check the following also
storing data locally on the iphone
Store data locally IOS
There is some more option to locally
1. Using LocalDB - its little bit pain but not bad that much
2. Using XML file - you should have the method to retrieve the data.Its pretty easy
3. Using Plist - This is also very easy can done through few lines.
4. NSUserDefaults - This can be use only as few cases like User information, store tokens.
Got it!
I am currently working on the app that is going to use database to store items. The first thing that everybody say, when it comes to store data in iOS is Core Data.
But, after few days of looking through tutorials and docs, I have a big question.
Let me explain architecture a little bit more. So we have a backend, where you can add items, also, we have iOS and Android application. I am creating a Core Data model for our database.
What we want,is to check if there is update for database and download it. The problem is that we don't use JSON or XML, we are using the new sqlite file.
Since Core data creates three files for database, which are:
db.sqlite
db.sqlite-wal
db.sqlite-shm
Is core data able to replace "db.sqlite" with the new one, that is downloaded from server?
Thought the idea of replacing the database file instead of importing objects to it is very tempting it's highly discouraged to mess up with sqlite database created by CoreData. You should never touch it manually, when you do, you'll very likely end up with broken DB or messed up data.
So no, CoreDate is not able to replace underlaying sqlite file. You should instead import your data using CoreData stack, that's how it's designed. Creating JSON/XML service is the best way you can go.
BUT IN THEORY and in case you would be able to keep CD internal information stored in the db untouched, it should be possible to replace the sqlite file. If your database is read-only for users, it might work, but if users are able to create or modify records, forget about it right now.
First, you'd have to tear down all CoreData stacks (Managed Object Context, Persistent Store Coordinator, Managed Object Model) that might be using it before you replace it, replace the file and re-create CoreData stack(s).
db.sqlite is the main database file, the other two are temporary files, Write ahead log (wal) and Shared memory (smh), so you don't need these two.
Remember you never MUST NOT change the structure of the database, just data in it!!!
However, as stated in the beginning, I do not recommend this approach at all.
I'm trying to build my first Swift app and I think Realm may be a good option for my database. This might be a totally stupid question, but will my users be able to access the data on my database without an internet connection? I'm fairly certain that the answer is yes, but I just want to make sure.
As a side note, I want the data to be stored on the users phone (not a server or anything like that)
Thanks for the help
Yep! Realm is a completely offline, local database solution. There's no online component, but if you do decide to, you can sync data from Realm online using third party cloud services like Parse (Or just literally copying the database file to Dropbox).
By default, all data saved with Realm is stored in a file called 'default.realm' in the Documents directory of your app, but you can easily explicitly set where you want the data to be saved.
I've checked a lot of sites and answers and I can't find any solutions specific to my problem.
I don't need to change the schema for my Core data model, all I need is to modify (add some) content to the current backing SQL Database.
Any direction on this will be welcome. Thanks.
PS: I tried Apple docs and they were about as useful to me as sunshine on Mecury.
Also go easy please, I'm a beginner.
Thanks.
UPDATE;
To shed more light on my issue, my app works as thus. I have preloaded static information on the app that can't be changed by the user, each day has new content. Every month, I push an update with entirely new content specific to that month. However, when my app entered production, upon the update I pushed for this month, my users were complaining that they couldn't access the month's data. This led to me spamming them with Push notifications to have them delete the app and do a fresh install to access the new data.
How can I fix this issue? my schema stays the same, only the data changes.
If I understand correctly you want to pre-fill a Core Data database ?
If you don't care about pre-existing data on existing app, you can make an iPhone or Mac app with the same model, and let it generate the database, like explain here (Any way to pre populate core data?) it's also the way recommended in a really great book if you want to learn more about Core Data (http://pragprog.com/book/mzcd2/core-data).
Do not ever make SQL request directly, Core Data work in his own magic way.
Don't work on the SQLite-Database directly. Change all your Data through NSManagedObjectContext! To find a good strategy look up examples from Batch-Importing.
Update: You could actually have two PersistentStores (one with just static data (readonly) and the other one with user-generated data). You could interchange the readonly which you prefilled with a commandline util and downloaded from a server. You cannot have direct relationships between those two store though.
I would say that it depends on the amount of data in this prefilled store wether you should go this way or just use a plist and reference some string constants in your user data store. Try to do it with a plist as this is the simpler approach.
I am currently building an iPhone app that is using Core Data and sqlite databases where the user will be reading static information from the database throughout the app. I have the issue where we may update the information in the database but not want to do a full update of the app, just the database. Can someone please help me out with either a easy function or a tutorial of how to go to a website or server and download the file which will replace the database that we have already put into the app? I'm new in xcode and I`m doing my first app.... thanks for your help
I think what would be a good idea is for your website to publish the data that must be stored in sqllite over REST, possibly in JSON or XML format.
This blog post describes how you could do just that. I must say that its approach to retrieving the content from the webservice is kind of low-level but it'll get the job done. Maybe RestKit can help you take care of all the low-level networking/http stuff.
I assume you want the static data locally so you don't require a constant internet connection for your app to work. Another option is to request the static data from the web and persist it in a file (NSUserDefaults etc...). But, that depends on how complicated the static data is and whether you have to query into that data. If you need to issue queries on that static data, a DB is definitely better.
You can also do a combination where you download updated DB if available async while your app works. You could have a setting in user defaults which is the current static data DB. If updated, you switch the current setting and re-establish the DB connection under a lock.
Here's how to make an http request using iOS.
rest web services in iphone
If you're downloading db data, don't convert the NSData to a string like in that sample ...
Also, ASI-HTTP-Request is popular. Here's samples on how to download a file:
http://allseeing-i.com/ASIHTTPRequest/How-to-use
http://www.cocoadev.com/index.pl?NSUserDefaults