Lala's Program Note 實作記錄: 31. 匯入預設的 Core Data 資料到專案裡

since: 2011/09/25
update: 2011/09/26


A. 準備好已儲存資料的 Core Data sqlite 檔案.
   方法 1:
   直接在模擬器的 UI 操作介面中先建好資料, 然後到 iPhone Simulator Directory 裡,
   將 app Documents 目錄下的 xxx.sqlite 檔 copy 出來.
   說明: 可先建立 iPhone Simulator Directory 的 symbolic link, 方便使用.

   方法 2:
   在實機測試時, 輸入想要預設儲存的資料, 然後配合:
   利用 iTunes 備份與回復 Core Data 資料, 將 xxx.sqlite 檔 copy 出來.

   方法 3: (未試過)
   藉由 方法 1 或 方法 2, copy 出不含資料的空白資料庫, 然後利用:
   SQLite database browser 工具, 匯入 CSV 格式的資料到 xxx.sqlite 檔.

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B. 將準備好的 xxx.sql 檔案加到專案裡:

   先新增一個 Resources 的 Group, 然後再將 xxx.sqlite 檔加進來.

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C. 開啟 Lala_s_Program_NoteAppDelegate.m 檔, 修改如下:

/**
 Returns the persistent store coordinator for the application.
 If the coordinator doesn't already exist, it is created and the application's store added to it.
 */
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
    if (__persistentStoreCoordinator != nil)
    {
        return __persistentStoreCoordinator;
    }
   
    /*
    //@add: import prepopulated sqlite data to a coredata db
     */
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentsDirectory = [paths objectAtIndex:0];
   
    // a. 要存放預設資料的位置, 即 app 在執行時會讀取 .sql 的地方
    NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"Lala_s_Program_Note.sqlite"];
    //NSLog(@"writableDBPath %@", writableDBPath);
    /*
     writableDBPath
    
     Simulator: /Users/lanli/Library/Application Support/iPhone Simulator/4.3.2/Applications/8F85FBE9-9C82-4DCD-84D5-C68173657E4C/Documents/Lala_s_Program_Note.sqlite
    
     iDevice: /var/mobile/Applications/C3F2AB7F-A296-4E9D-96C9-554E9499E1D4/Documents/Lala_s_Program_Note.sqlite
     */
   
    // b. 一開始加到專案裡的 .sql 位置, 直接就在 app 的目錄下
    NSString *defaultStorePath = [[NSBundle mainBundle] pathForResource:@"Lala_s_Program_Note" ofType:@"sqlite"];
    //NSLog(@"defalultStorePath %@", defaultStorePath);
    /*
     defalultStorePath
    
     Simulator: /Users/lanli/Library/Application Support/iPhone Simulator/4.3.2/Applications/8F85FBE9-9C82-4DCD-84D5-C68173657E4C/Lala's Program Note.app/Lala_s_Program_Note.sqlite
    
     iDevice: /var/mobile/Applications/C3F2AB7F-A296-4E9D-96C9-554E9499E1D4/Lala's Program Note.app/Lala_s_Program_Note.sqlite
     */   
   
    // c. app 在執行時讀取 .sql 的 URL地方
    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Lala_s_Program_Note.sqlite"];
    //NSLog(@"store URL %@", storeURL);
    /*
     store URL
    
     Simulator: file://localhost/Users/lanli/Library/Application%20Support/iPhone%20Simulator/4.3.2/Applications/8F85FBE9-9C82-4DCD-84D5-C68173657E4C/Documents/Lala_s_Program_Note.sqlite
    
     iDevice: file://localhost/var/mobile/Applications/C3F2AB7F-A296-4E9D-96C9-554E9499E1D4/Documents/Lala_s_Program_Note.sqlite
     */
   
    // Put down default db if it doesn't already exist
    NSFileManager *fileManager = [NSFileManager defaultManager];
    if (![fileManager fileExistsAtPath:writableDBPath]) {
        if (defaultStorePath) {
            [fileManager copyItemAtPath:defaultStorePath toPath:writableDBPath error:NULL];
        }
    }
   
    //@original:
    //NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"Lala_s_Program_Note.sqlite"];
    NSError *error = nil;
    __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error])
    {
        . . . .
        //NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
        //abort();
        //@update
        [Common showCoreDataError];
    }   
   
    return __persistentStoreCoordinator;
}

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D. 結果圖: