iPhone - база данных SQLite Прочитано

Question

Я пытаюсь сделать базовое приложение. Список
Мои файлы:

DatabaseClass.h and .m, 
IDRGameAppDelegate.h and .m, 
scoredb.sqlite, 
ScoreViewController.h and .m, 
MainWindow.xib // Main Window 
ScoreWindow.xib //Show Score Window 

1.) моя база данных;

CREATE TABLE "game" ("id" INTEGER PRIMARY KEY ,"name" VARCHAR(32),"score" VARCHAR(20)); 
INSERT INTO "game" VALUES(1,'interclock','1.234'); 
INSERT INTO "game" VALUES(2,'dui','345'); 
INSERT INTO "game" VALUES(3,'reflex','987'); 

2-) я создал DatabaseClass.h и DatabaseClass.m

DatabaseClass.h является:

#import <Foundation/Foundation.h> 
@interface DatabaseClass : NSObject { 

    NSString *name; 
    NSString *score; 
} 
@property (nonatomic, retain) NSString *name; 
@property (nonatomic, retain) NSString *score; 
-(id)initWithName:(NSString *)n score:(NSString *)s; 
@end 

DatabaseClass.m является;

#import "DatabaseClass.h" 
@implementation DatabaseClass 
@synthesize name, score; 
-(id)initWithName:(NSString *)n score:(NSString *)s{ 
    self.name = n; 
    self.score = s; 
    return self; 
} 
@end 

мой IDRGameAppDelegate.h есть;

#import <UIKit/UIKit.h> 
#import <sqlite3.h> // Import the SQLite database framework 

@class IDRGameViewController , ScoreViewController ; 


@interface IDRGameAppDelegate : NSObject <UIApplicationDelegate> { 

    IBOutlet UIWindow *window; 
    IBOutlet IDRGameViewController *viewController; 
    IBOutlet ScoreViewController *scoreViewController; 


    // Database variables 
    NSString *databaseName; 
    NSString *databasePath; 

    // Array to store the animal objects 
    NSMutableArray *scores; 
} 

- (void)flipToScore; 
- (void)scoreToMainBack; 

-(void) checkAndCreateDatabase; 
-(void) readScoreFromDatabase; 

@property (nonatomic, retain) UIWindow *window; 
@property (nonatomic, retain) IDRGameViewController *viewController; 
@property (nonatomic, retain) ScoreViewController *scoreViewController; 
@property (nonatomic, retain) NSMutableArray *scores; 

@end 

IDRGameAppDelegate.m is;

#import "IDRGameAppDelegate.h" 
#import "IDRGameViewController.h" 
#import "ScoreViewController.h" 
#import "DatabaseClass.h" 


@implementation IDRGameAppDelegate 

@synthesize window; 
@synthesize viewController; 
@synthesize scoreViewController; 

@synthesize scores; 



- (void)applicationDidFinishLaunching:(UIApplication *)application { 

    // Setup some globals 
    databaseName = @"scoredb.sqlite"; 

    // Get the path to the documents directory and append the databaseName 
    NSArray *documentPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
    NSString *documentsDir = [documentPaths objectAtIndex:0]; 
    databasePath = [documentsDir stringByAppendingPathComponent:databaseName]; 

    // Execute the "checkAndCreateDatabase" function 
    [self checkAndCreateDatabase]; 

    // Query the database for all animal records and construct the "animals" array 
    [self readScoreFromDatabase]; 

    // Override point for customization after app launch  
    [window addSubview:viewController.view]; 
    [window makeKeyAndVisible]; 
} 

- (void)dealloc { 
    [scores release]; 
    [viewController release]; 
    [window release]; 
    [super dealloc]; 
} 


-(void) checkAndCreateDatabase{ 
    // Check if the SQL database has already been saved to the users phone, if not then copy it over 
    BOOL success; 

    // Create a FileManager object, we will use this to check the status 
    // of the database and to copy it over if required 
    NSFileManager *fileManager = [NSFileManager defaultManager]; 

    // Check if the database has already been created in the users filesystem 
    success = [fileManager fileExistsAtPath:databasePath]; 

    // If the database already exists then return without doing anything 
    if(success) return; 

    // If not then proceed to copy the database from the application to the users filesystem 

    // Get the path to the database in the application package 
    NSString *databasePathFromApp = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:databaseName]; 

    // Copy the database from the package to the users filesystem 
    [fileManager copyItemAtPath:databasePathFromApp toPath:databasePath error:nil]; 

    [fileManager release]; 
} 


-(void) readScoreFromDatabase { 
    // Setup the database object 
    sqlite3 *database; 

    // Init the animals Array 
    scores = [[NSMutableArray alloc] init]; 

    // Open the database from the users filessytem 
    if(sqlite3_open([databasePath UTF8String], &database) == SQLITE_OK) { 
     // Setup the SQL Statement and compile it for faster access 
     const char *sqlStatement = "select * from game"; 
     sqlite3_stmt *compiledStatement; 
     if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { 



      // Loop through the results and add them to the feeds array 
      while(sqlite3_step(compiledStatement) == SQLITE_ROW) { 
       // Read the data from the result row 

       NSString *aName =[NSString stringWithCString:(char *)sqlite3_column_text(compiledStatement, 2)]; 
       NSString *aScore =[NSString stringWithCString:(char *)sqlite3_column_text(compiledStatement, 3)]; 

       //NSString *aName = [NSString stringWithString:(NSString *)sqlite3_column_text(compiledStatement, 2)]; 
       //NSString *aScore = [NSString stringWithString:(NSString *)sqlite3_column_text(compiledStatement, 3)]; 



       // Create a new animal object with the data from the database 
       DatabaseClass *dbOBJ = [[DatabaseClass alloc] initWithName:aName score:aScore]; 

       // Add the animal object to the animals Array 
       [scores addObject:dbOBJ]; 

       [dbOBJ release]; 
      } 
     } 
     // Release the compiled statement from memory 
     sqlite3_finalize(compiledStatement); 

    } 
    sqlite3_close(database); 

} 


- (void)flipToScore { 


    ScoreViewController *aSecondView = [[ScoreViewController alloc] initWithNibName:@"ScoreWindow" bundle:nil]; 
    [self setScoreViewController:aSecondView]; 
    [aSecondView release]; 

    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationDuration:2.0]; 
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:window cache:YES]; 
    [viewController.view removeFromSuperview]; 
    [self.window addSubview:[scoreViewController view]]; 
    [UIView commitAnimations]; 

} 

- (void)scoreToMainBack { 



    [UIView beginAnimations:nil context:NULL]; 
    [UIView setAnimationDuration:2.0]; 
    [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:window cache:NO]; 


    [scoreViewController.view removeFromSuperview]; 
    [self.window addSubview:[viewController view]]; 

    [UIView commitAnimations]; 


    [scoreViewController release]; 
    scoreViewController = nil; 

} 
@end 

ScoreViewController.h is;

#import <UIKit/UIKit.h> 

@interface ScoreViewController : UIViewController { 

    IBOutlet UILabel *gameNameLabel; 
    IBOutlet UILabel *gameScoreLabel; 


} 
@property (nonatomic, retain) IBOutlet UILabel *gameNameLabel; 
@property (nonatomic, retain) IBOutlet UILabel *gameScoreLabel; 

-(IBAction)refreshClick:(id)sender; 

@end 

и, наконец, ScoreViewController.m is;

#import "ScoreViewController.h" 
#import "DatabaseClass.h" 
#import "IDRGameAppDelegate.h" 

@implementation ScoreViewController 

@synthesize gameNameLabel,gameScoreLabel; 


/* 
// The designated initializer. Override to perform setup that is required before the view is loaded. 
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { 
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) { 
     // Custom initialization 
    } 
    return self; 
} 
*/ 

/* 
// Implement loadView to create a view hierarchy programmatically, without using a nib. 
- (void)loadView { 
} 
*/ 

/* 
// Implement viewDidLoad to do additional setup after loading the view, typically from a nib. 
- (void)viewDidLoad { 
    [super viewDidLoad]; 
} 
*/ 

/* 
// Override to allow orientations other than the default portrait orientation. 
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { 
    // Return YES for supported orientations 
    return (interfaceOrientation == UIInterfaceOrientationPortrait); 
} 
*/ 

-(IBAction)refreshClick:(id)sender { 

    // Navigation logic -- create and push a new view controller 
    IDRGameAppDelegate *appDelegate = (IDRGameAppDelegate *)[[UIApplication sharedApplication] delegate]; 
    DatabaseClass *dbOBJ = (DatabaseClass *)[appDelegate.scores objectAtIndex:0]; 



    gameNameLabel.text = [dbOBJ name]; 
    gameScoreLabel.text = [dbOBJ score]; 


} 




- (void)didReceiveMemoryWarning { 
    [super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview 
    // Release anything that's not essential, such as cached data 
} 


- (void)dealloc { 
    [super dealloc]; 
} 


@end 

Проблема: когда я нажимаю кнопку refreshButton, программа блокируется и ломается, но я не вижу ошибки.

Программа не работает Я не читал и не показывал записи базы данных. В чем проблема?

Answer 1

Почему вы решили придерживаться непосредственно SQLite на iPhone? После того, как iPhone OS 3.0 доступен для всех пользователей iPhone, я бы рекомендовал использовать эту абстракцию базы данных. Он довольно прост в использовании и не позволяет вам кодировать кучу кода доступа к базе данных.

В блоге Mike Swans это полезное введение в основные данные, которые могут послужить отправной точкой для вашей разработки.

В качестве части справочной документации по iPhone Apple опубликовала Core Data Tutorial for the iPhone OS, которая охватывает специфические особенности iPhone.

Я использовал его в приложении самостоятельно и нашел, что он действительно экономит время по сравнению с кодом базы данных SQLite, который у меня был раньше.