Adding Multiple Configurations/ Persistent Store to core data swift

Question

Hi I followed http://commandshift.co.uk/blog/2013/06/06/multiple-persistent-stores-in-core-data/ tutorial and created multiple configurations for core data. Some of my entities are in Configuration "SQLStorage" and some are in "InMemory".

I want SQLStorage configuration to make use of NSSQLiteStoreType and InMemory configuration to make use of NSInMemoryStoreType. So here is how I modified my persistentStoreCoordinator getter.

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
        // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
        // Create the coordinator and store
        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
        let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
        var failureReason = "There was an error creating or loading the application's saved data."
        do {
            try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: "SQLStorage", URL: url, options: nil)
        } catch {
            // Report any error we got.
            var dict = [String: AnyObject]()
            dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
            dict[NSLocalizedFailureReasonErrorKey] = failureReason

            dict[NSUnderlyingErrorKey] = error as NSError
            let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
            // Replace this with code to handle the error appropriately.
            // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
            abort()
        }
        do {
            try coordinator.addPersistentStoreWithType(NSInMemoryStoreType, configuration: "InMemory", URL: url, options: nil)
        } catch {
            // Report any error we got.
            var dict = [String: AnyObject]()
            dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
            dict[NSLocalizedFailureReasonErrorKey] = failureReason

            dict[NSUnderlyingErrorKey] = error as NSError
            let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
            // Replace this with code to handle the error appropriately.
            // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
            abort()
        }

        return coordinator
    }()

Overtime I try to compile this code I get the error :

CoreData: error: -addPersistentStoreWithType:InMemory configuration:InMemory URL:file:///Users/developer/Library/Developer/CoreSimulator/Devices/1D943405-C5AD-4CD4-9413-070DFC5334AB/data/Containers/Data/Application/2BEAF446-6F32-405B-B2B6-6B298D45E103/Documents/SingleViewCoreData.sqlite options:(null) ... returned error Error Domain=NSCocoaErrorDomain Code=134080 "(null)" UserInfo={NSUnderlyingException=Can't add the same store twice} with userInfo dictionary { NSUnderlyingException = "Can't add the same store twice"; }

2016-08-16 02:25:05.181 EncryptedCoredata[9457:461607] Unresolved error Error Domain=YOUR_ERROR_DOMAIN Code=9999 "Failed to initialize the application's saved data" UserInfo={NSLocalizedDescription=Failed to initialize the application's saved data, NSLocalizedFailureReason=There was an error creating or loading the application's saved data., NSUnderlyingError=0x7ff25a840ba0 {Error Domain=NSCocoaErrorDomain Code=134080 "(null)" UserInfo={NSUnderlyingException=Can't add the same store twice}}}, [NSLocalizedDescription: Failed to initialize the application's saved data, NSLocalizedFailureReason: There was an error creating or loading the application's saved data., NSUnderlyingError: Error Domain=NSCocoaErrorDomain Code=134080 "(null)" UserInfo={NSUnderlyingException=Can't add the same store twice}]

What might be the issue ?? Any help would be appreciated. Thanks in advance.

Answer 1

The immediate error is because you aren't changing the URL in between the 2 do blocks, so you're trying to add 2 different stores at the same path which you can't do.