Should I use Core Data?

I'm starting a new document-based application. Is Core Data the way of the future, or just a convenience for specific types of apps? That is, in the "old days" you would override -[NSDocument dataOfType:] and readFromData: to archive your objects. It seems appealing to use Core Data and get automatic archiving in XML, SQL, and binary all for free, but the tutorials I've gone through all seem directed at a very different kind of app than mine. (Rather database-like, but I suppose the demo has to look like something.) The old "Sketch" example, which uses old-style archiving, hasn't been updated in years. Which direction to go?

Look up HyperCard in Wikipedia for a good explanation. In short, I'm developing a GUI-based mini-app environment, where users can create buttons & fields, and hook them up with an elementary scripting language. I've written the compiler & interpreter, am starting the surrounding framework.
"Have you looked at the Apple HIGs lately?" Dude, I was reading "Inside Macintosh" back in 1984.
Mobile platform? Since I'm using garbage collection, I'm shut out of iPhone/iPad, at least for the time being.

Similar Messages

Using core data with a database

Here is where I am at. I have a trivia app in development that will have over 1000 questions, so a database is inevitable. We recently created a test sqlite database and read in some entries and it worked.
We were looking into exploiting the features of Core Data in our app, but this would involve creating a set of managed objects, a context, and the essentials for a Core Data scheme to function, and then use these models to fetch data from a database.
The database is not created yet. We are starting fresh and simply wish to see if we can use core data to work with a database that could be created once the model is in place. Is it possible to create a 1000 or more entry database whose entries could relate to a Core Data entity or set of entities, and then use Core Data to fetch the data from these entries as we please?

We will not be reusing any code. I apologize for the confusion. This is the start of the app regarding database management, and we have not yet created the database that will hold the questions for this app.
Alright, so you two are both suggesting to set up a model and allow the creation of the sqlite store, which if my research is correct, involves a .sqlite file with a "Z_" following each attribute, and then adding entries here. This sounds fair enough. I had not known if this was going against the mainstream use of core data or not.
Thanks you two. I'm going to leave the question open for a little while longer to see if any other opinions come up.

Should I use a data retrieval service or software to recover data ?

Please pardon the length of this post.
Here's the setup for our office:
Computer 1:
10.4.8 OS X
1 GHZ PowerPC G4: silver grey tower, grey apple
1MB L3 Cache
256 MB DDR SDRAM
Computer 2:
10.4.8 OS X
Dual 450 MHZ PowerPC G4: blue grey tower, blue apple
256 MB SDRAM
Computer 3:
10.4.8 OS X
1 GHZ PowerPC G4 IMac Flat Screen:
256 MB DDR SDRAM
I have 2 LaCie Big Disk d2 Extremes daisy chained and connected to the IMac. We use the first to store all of our data to keep our local disks free. The second d2 is the backup to the first. The other 2 computers connect to the d2's via an ethernet hub. The d2's are each partitioned into 4 compartments.
A couple of days ago I started the system up when I got in in the morning, and the main d2 would not open. I ran disk utility, but it said that the drive was damaged beyond it's ability to repair. I ran DiskWarrior, and it gave me this message:
"The directory of disk 'G4' cannot be rebuilt. The disk was not modified. The original directory is too severely damaged. It appears another disk utility has erased critical directory information. (3004, 2176)."
I contacted Disk Warrior tech support and after a series of exchanges that had me send him dated extracted from the terminal function, he said this:
"It appears that the concatenated RAID inside your LaCie
drive has failed (your 500GB drive is actually 2 250GB
hard drives). That is why we only saw 2 partitions
on "disk3". A possible cause could be a failed bridge
in the case.
You may be looking at sending this drive to a data recovery service.
However, it is possible that we may be able to recover data
from the partitions that we CAN see. What we would be doing would cause no damage to your data
unless the hard drives were having a mechanical failure (ie, the
head crashed and was contacting the platters, similar to scratching
a record). But from what I've seen, I don't feel that is the case.
I believe the piece of hardware that 'bridges' the two drives to
make them act as one has failed. that's why we can only see data
about 1 of the 2 drives in the case.
We would only be attempting to gather data off the drive. Since
data recovery services sometimes charge for amount of data retrieved,
it's up to you how you want to proceed."
Most of the data from the past 5 years for our business stands at being lost. Only some of it had been properly backed up on the second drive, due to some back up software issues. I want to do whatever I can to retrieve all of, or at least some of the data. From what the Alsoft technician said, do you think that the data recovery software available to the consumer is going to be robust enough to retrieve at least the data from the one disk in the drive that is recognizable (there are 2 250gig disks in the d2X. Only one is responding at all). If so, do these Softwares further damage the disks? Or should I just send the drive to a data recovery service?
I'd like to try to extract some of it myself via over the counter retrieval software, but I don't know whether to trust these programs?
Any advice would be greatly appreciated.
Thanks in advance.
Peter McConnell
1 GHZ PowerPC G4 IMac Flat Screen Mac OS X (10.4.8) Posted

Peter
My 2 cents:
I have used FileSalvage
http://www.subrosasoft.com/OSXSoftware/index.php?mainpage=product_info&productsid=1
to recover files from damaged disks. It works as advertised, within limits. Some files may be too damaged to recover. More importantly yo get to scan the disk before actually recovering, and it will give you a list of what it thinks it can recover.
My experience was that it recovered approx 85% of the data.
YMMV but they do have a trial.
Regards
TD

What cable hookup should I use for DAT to hard drive conversion

Hi,
I have a Fostex D5 Dat machine with xlr & optical digital outputs and analog I/O right/left channels. I want to get these DAT tapes into my iMac (I have Logic 7 and will simply be using it to copy these to an external drive and then later master them. My goal is to get the music off the DAT tapes and onto the drive).
I also have an M-Audio Firewire Solo with s/pdif O/I and balanced RCA line outputs and unbalanced RCA line inputs. I will use this to interface with the iMac using the firewire connection to get the audio onto the disc.
My question relates to what is the best hookup I can use with this equipment and these I/Os for the best sound/signal? I've transferred a few songs using this setup: XLR cable from DAT analog output to the unbalanced line inputs on the Firewire solo then Firewire Solo to iMac through the fire wire.
Is there an XLR to S/PDIF cable I can run from the digital XLR on the DAT into the S/PDF input on the Firewire Solo? If I go out from the digital XLR on the DAT to the Firewire Solo I will be putting the R & L channels into one track (Firewire Solo inputs are #1 & #2 which give you the stereo R & L tracks.
I want to be sure to get the best quality transfer I have but I'm not sure how to do it.
Thanks,
Bob

hi bob, the XLR out is AES/EBU standard and can be connected to the rca s/p dif socket with a special adapter lead. best way to go. least amount of jitter. don't do analog here unless there is really no other way.

Derived Values in Core Data

Using Core Data - I have created a named NSManagedObject that has both a start time and end time.
I'd like to display a list of these Session and I'd like the SECTION headers to break per day, based on a Session's start date. So, I'm storing a time - and I need to group by a date.
Would I simply add a readonly property 'startDate' to the literal Session code (.h,.m) that Core Data generated from my data model - in which I would derive the start date from the start time? or would this be a case for declaring a 'transient' property in my Core Data model? I don't exactly know when to use or not to use Transient properties.
It would be used as follows:
fetchedResultsController_ =
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
managedObjectContext:managedObjectContext_
sectionNameKeyPath:@"startDate"
cacheName:cacheName];
Will this manually defined property actually work in this method?
-Luther

Dear Abir,
Thanks a lot for your exact reply.
In tracking tab of UWL what you see is NOT the description given for workflow, it is the Work Item Text for that workflow.
This is absoltely correct. I inserted the container variables in workitem text from PFTC as you suggested. It worked like a Magic!!!
KR,
Bharath

Info.plist issues with Core Data

I created a new project, selecting to use Core Data. However, the info.plist does not include the standard iPhone project options like status bar style and icon gloss etc. I tried copying and pasting the status bar style key and value from another project's plist, but this has no effect.
Any help would be appreciated please.

Verduomo wrote:
I created a new project, selecting to use Core Data. However, the info.plist does not include the standard iPhone project options like status bar style and icon gloss etc.
Shine is added by Apple now. I get shine without a 'prerendered' key.
What SDK are you working with?
Did you add a 'prerendered' key?
<key>UIPrerenderedIcon</key>
<true/>

Core Data Issue

I am creating a coredata sqlite database file in a mac app (using core data) and am attempting to use the same database and core data model in an ipad app.   I have copied all NSManagedObject files and the .xcdatamodeld directory from the mac app to the ios app. Even though all files are identical I get "
The model used to open the store is incompatible with the one used to create the store" when trying to read from the store in the app. My question is what is actually being compared when this error is thrown? It looks like it throws the error following SELECT Z_VERSION, Z_UUID, Z_PLIST FROM Z_METADATA.   What is a z_uuid? Any ideas on how to debug this?   my error dump is below.
2014-05-06 12:57:29.118 Genome[9055:60b] CoreData: sql: SELECT Z_VERSION, Z_UUID, Z_PLIST FROM Z_METADATA
2014-05-06 12:57:29.119 Genome[9055:60b] CoreData: annotation: Disconnecting from sqlite database.
2014-05-06 12:57:29.121 Genome[9055:60b] Unresolved error Error Domain=NSCocoaErrorDomain Code=134100 "The operation couldn’t be completed. (Cocoa error 134100.)" UserInfo=0x109527050 {metadata={
    NSPersistenceFrameworkVersion = 481;
    NSStoreModelVersionHashes =     {
        Annotation = <d4eb8bbc 528c6ac9 3cc1decb ca49790e 9933c09b faf47ec9 108fb9b4 b083e144>;
        Band = <14c5dda0 3db4c5c7 27952ce6 5421b597 6d97bed9 b6f225c7 0d956b54 2cfc8282>;
        Gene = <e70a2ed2 fa4c0c3e 1fb8eabc f0f1c26b 9dadb033 0c9198fe 9ba2393e c1a3f9c2>;
        Test = <051b8cd1 849daecf 7a94ac5a 87134d9b 1db8b51c 60bdca34 cb828268 01d6a73a>;
        User = <ebf4a8c8 7209296b 30bdf66c bd7a3dac afa9c8c5 d04f363f 14469686 ba458804>;
        Variant = <58231e33 52687ba7 053846d2 e8d27ed2 58ec690b 2fb09efc 303f299f 2592d6f5>;
    NSStoreModelVersionHashesVersion = 3;
    NSStoreModelVersionIdentifiers =     (
    NSStoreType = SQLite;
    NSStoreUUID = "9B3D312C-95C8-45E3-9F2F-2581E88403A8";
    "_NSAutoVacuumLevel" = 2;
}, reason=The model used to open the store is incompatible with the one used to create the store}, {
    metadata =     {
        NSPersistenceFrameworkVersion = 481;
        NSStoreModelVersionHashes =         {
            Annotation = <d4eb8bbc 528c6ac9 3cc1decb ca49790e 9933c09b faf47ec9 108fb9b4 b083e144>;
            Band = <14c5dda0 3db4c5c7 27952ce6 5421b597 6d97bed9 b6f225c7 0d956b54 2cfc8282>;
            Gene = <e70a2ed2 fa4c0c3e 1fb8eabc f0f1c26b 9dadb033 0c9198fe 9ba2393e c1a3f9c2>;
            Test = <051b8cd1 849daecf 7a94ac5a 87134d9b 1db8b51c 60bdca34 cb828268 01d6a73a>;
            User = <ebf4a8c8 7209296b 30bdf66c bd7a3dac afa9c8c5 d04f363f 14469686 ba458804>;
            Variant = <58231e33 52687ba7 053846d2 e8d27ed2 58ec690b 2fb09efc 303f299f 2592d6f5>;
        NSStoreModelVersionHashesVersion = 3;
        NSStoreModelVersionIdentifiers =         (
        NSStoreType = SQLite;
        NSStoreUUID = "9B3D312C-95C8-45E3-9F2F-2581E88403A8";
        "_NSAutoVacuumLevel" = 2;
    reason = "The model used to open the store is incompatible with the one used to create the store";

That is not it. I acually had it working with Mavaricks and ios7 and then something changed.   I am wondering what exactly is being compared when the The model used to open the store is incompatible with the one used to create the store error is thrown. It is obviously not the columns of the db and properties of the managed objects because they are identical.

Core Data and migration question.

Lets say software v1.0 uses the core data model version coreDataModelA.xcdatamodel ...
Software v2.0 uses core data model version coreDataModelB.xcdatamodel...
and Software v3.0 uses core data model version coreDataModelC.xcdatamodel.
Assuming migrations were done from coreDataModelA.xcdatamodel to coreDataModelB.xcdatamodel and then to coreDataModelC.xcdatamodel, if a user is upgrading from software version 1.0 to software version 3.0 (skipping 2.0).... will it successfully migrate for them?
I'm assuming an app has only one xcmappingmodel file.

Does this help?

Core data binding not working

in my project I used core data and binding to produce data on document based program.
I have used multiple entities and they worked fine and then they stopped working and I don't know why.
all the text fields now have "()" in them with space in between them, and will not add to the database. so the field shows a junk value and will not bind properly to the database.
how would I start to debug this I have been searching but I don't know where to start, mainly i dont know what the problem is.

Binding works one way. This means that textInput.text changes
to match the value of account.identifier, not the other way around.
While I think it's theoretically possible to create a binding the
other way (I haven't played with binding in ActionScript), it makes
more sense to listen to the TextInput's change event to get changes
to the text field.
Or, you can create a model in the MXML and bind one its
properties to the textinput's value. Look in the docs about the
mx:Model tag for details.

Core data details

I have to use core data in my new application,and i hav to send my data to server through http post ,m a new comer to i Phone devlopment world.I M having no idea. is any who can help me out,code would b appreciated
Thanx in advance

Hi There, This forum isn't really for programming questions, it's more for end-user support.
There are also developer forums and help in Apple Dev Connection
Hope this helps

Using JODA Date in Entity Bean

We are planning to use JODA open source in our project which is actually a replacement for Java Calendar and Date. Like to know how can we map the JODA Datetime to date columns in the table. Refer the link http://edocs.bea.com/wls/docs60/ejb/cmp.html for the supported data types. Is there any server specific extension available to support new data types.
If not, we should still use util.Date in the entity bean but expose as DateTime outside. We'll do the conversion between util.Date and DateTime in the entity bean since we don't want to expose java.util.Date outside teh entity bean.
But this restriction will fail for finder queries implemented through EJB QL unless the servic emethid calling the finder do the conversion to util.Date before calling. Is there a clean way to use JODA DateTime in Entity Bean

EJB doesn't support identity field. EJB expects you set primary key values explicitly. There is a well known pattern that makes use of a session bean to generate entity bean primary key. Your best option is to use BMP or give up auto increment identity fields.

Have family plan with 250 data which I almost use each month. Going on vacation and will be on the road for two weeks. Should I up my data for a month then change back. Is it worth it or should I just run over and pay the extra 15 per gig?

have family plan with 250 data which I almost use each month. Going on vacation and will be on the road for two weeks. Should I up my data for a month then change back. Is it worth it or should I just run over and pay the extra 15 per gig?

Hello mlazaretti. Vacation time is awesome. (Especially a road trip!) Since you will be going out for two weeks, you never know if having extra data may come in handy. I highly recommend switching to the next tier up so this way you have more data. This way it is only $10.00 more versus $15.00, and you dont have to worry about overages. Then change back at the start of the next billing cycle.
If you need help making this change let us know! Have a safe trip!
NicandroN_VZW
Follow us on twitter @VZWSupport

How should i use the two results sets in one single report data region?

Hi frnz,
I have to create a report using the below condition...
Here my given data set query gives you the two result sets ,so how should i use that two result sets information in single report....when i accessing that data set query it will take the values off the first result set not for the second result set.
without using sub report and look up functionality..... if possible
is there any way to achieve this.....Please let me know..
Thanks!

You cant get both resultsets in SSRS. SSRS dataset will only take the first resultset
you need to either create them as separate queries or merge them into a single resultset and return with ad additional hardcoded field which indicates resultset (ie resultset1,resultset2 etc)
Then inside SSRS report you can filter on the field to fetch individual resultsets at required places. While merging you need to make sure metadata of two resultsets are made consistent ie number of columns and correcponding column data types should be same.
In absence of required number of columns just put some placeholders using NULL
Please Mark This As Answer if it helps to solve the issue Visakh ---------------------------- http://visakhm.blogspot.com/ https://www.facebook.com/VmBlogs

What cable should I use to transfer data from an early 2008 MacBook to a new MacBook Pro?

Just purchased a new MacBook Pro. Need to transfer data from my Early 2008 MacBook. What cable should I use?

Firewire with a Thunderbolt.Firewire adapter.
http://store.apple.com/us/product/MD464ZM/A/apple-thunderbolt-to-firewire-adapte r
Ciao.

What should I use BCS or directly connect to sql server to get data.

Hi All,
I have a requierment where the data is in the sql server.
We are using sharepoint webpart to show the data from the sql.
Should i get the data from the sql server using connection string.
Is there any better way to get data from Sql server table and show that in the custom asp.net form.
Regards
Vinod

As I see the questions is in SharePoint 2013 forum.
Assuming you have SharePoint 2013/2010, you can create Create/Read/Update/Delete operations on directly sql table using BCS service of SharePoint. That will save you default development of web part and handle all information properly.
If you don't want to use BCS and sql (not sharepoint sql) information required, you can create custom web part/app part.
Thanks, Ashish | Please mark a post helpful/answer if it is helpful or answer your query.

Should I use Core Data?

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