I have an experience with NSFetchedResultsController like this below is sample project that can manage 2 CoreData containers of 2 SQLite files with the same CoreData model. https://www.dropbox.com/s/joj2n5jqmkkbson/test0002-2ContainerWork.zip?dl=0 However, I try to implement the same concept with SwiftUI like this below sample project. https://www.dropbox.com/s/wn1lxwmafg3fp63/testCoreData3.zip?dl=0 The important point, when I run only 1 view. This project can run correctly for each CoreData container. But when I run both views, the Xcode shows error !!! Here is code of TabView that call to run each view. import SwiftUI struct TabBarView: View { var body: some View { TabView { ContentView() .tabItem { Text("1") //Image("TabIcon"+"Account") Image(systemName: "list.bullet.rectangle.portrait") } .environment(\.managedObjectContext, PersistenceController.shared.container.viewContext) ContentView2() .tabItem { Text("2") //Image("TabIcon"+"Account") Image(systemName: "list.bullet.rectangle.portrait") } .environment(\.managedObjectContext, PersistenceController2.shared.container.viewContext) } } } It seems that SwiftUI can not support multiple containers and error show like below. 2022-12-07 21:06:41.411772+0700 testCoreData[38345:1010632] [error] warning: Multiple NSEntityDescriptions claim the NSManagedObject subclass 'Item' so +entity is unable to disambiguate. CoreData: warning: Multiple NSEntityDescriptions claim the NSManagedObject subclass 'Item' so +entity is unable to disambiguate. 2022-12-07 21:06:41.412037+0700 testCoreData[38345:1010632] [error] warning: 'Item' (0x60000083c630) from NSManagedObjectModel (0x600001c169e0) claims 'Item'. CoreData: warning: 'Item' (0x60000083c630) from NSManagedObjectModel (0x600001c169e0) claims 'Item'. 2022-12-07 21:06:41.412175+0700 testCoreData[38345:1010632] [error] warning: 'Item' (0x6000008306e0) from NSManagedObjectModel (0x600001c105a0) claims 'Item'. CoreData: warning: 'Item' (0x6000008306e0) from NSManagedObjectModel (0x600001c105a0) claims 'Item'. 2022-12-07 21:06:41.412302+0700 testCoreData[38345:1010632] [error] error: +[Item entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass CoreData: error: +[Item entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass 2022-12-07 21:06:41.557326+0700 testCoreData[38345:1010632] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'executeFetchRequest:error: A fetch request must have an entity.' May you please give me suggestion, how to work with 2 CoreData containers ? Note: In the real project, I may have many entities, such as 10 entities. So the suggestion from this below link is not practical for me. https://developer.apple.com/documentation/coredata/linking_data_between_two_core_data_stores

Here is my code ... var accountType = "Account" @FetchRequest( sortDescriptors: [NSSortDescriptor(keyPath: \JMAccount.displayOrder, ascending: true)] , predicate: NSPredicate(format: "(hidden < %@) AND (type == %@)", argumentArray: [Int(1), accountType]) , animation: .default ) private var items: FetchedResults<JMAccount> Then Xcode report error below ... "Cannot use instance member 'accountType' within property initializer; property initializers run before 'self' is available" How can I solve this error ? More info, I want to make multiple view with parameter to @FetchRequest. So I try to make variable for this parameter. If you have better idea, please suggest me.

I work with CoreData and need to backup/sync entire database to cloud server. The main CoreData is work well to show data in each view. But when I backup sqlite file to cloud server, then download sqlite file to another local location in iPhone, then I load NSPersistentContainer for this sqlite database file. Xcode shows "error: A fetch request must have an entity." Note: I'm sure that one NSPersistentContainer is load one sqlite file, two NSPersistentContainer is not point to the same file. Note2: This concept is work well in previous version of swift, but now I try to implement this concept with SwiftUI. Please suggest me for some ideas and/or solutions.

I want to create multiple view with difference query data by "accountType". By call: MyView(accountType: "Income") or MyView(accountType: "Expense") This below is code of "MyView". struct MyView: View {   @Environment(\.managedObjectContext) private var viewContext     var accountType = "Income"   @FetchRequest(     sortDescriptors: [NSSortDescriptor(keyPath: \JMAccount.displayOrder, ascending: true)]     , predicate: NSPredicate(format: "(type == %@)" , argumentArray: [accountType]  // With error       //, argumentArray: [Int(2), "Expense"]  // No error     )   , animation: .default )   private var items: FetchedResults<JMAccount>   var body: some View {     NavigationView {       List {         ForEach(items) { item in           Text(item.name!)         }   } }   } } Xcode shows error message at "argumentArray: [accountType]" Anyone has a solution for this issue? Please give me an advise.