我的SQL数据库在数据库forms不工作的实际设备，但在模拟器中工作正常

在我的应用程序中，我正在读取，写入和删除sqlite数据库（以dbforms），它在模拟器中工作正常，但在实际设备中不工作（给出错误： No such table found ）。我努力寻找解决scheme，但找不到一个或可能是我误解了一些东西。

我的数据库是在

/ users / My Name / library / developer / Core simulator / devices / devicen-id / data / application / app-id / documents / My database。

 - (NSString *) getWritableDBPath { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; return [documentsDir stringByAppendingPathComponent:mydaatabase]; } 

我很疑惑我在哪里需要复制我的数据库，而在实际的iOS设备上运行，什么是核心问题。任何帮助，这将是非常有帮助的

 -(void)createEditableCopyOfDatabaseIfNeeded { BOOL success; NSFileManager *fileManager1 = [NSFileManager defaultManager]; NSError *error; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:mydaatabase]; NSLog(@"=======%@", writableDBPath); success = [fileManager1 fileExistsAtPath:writableDBPath]; if (success) return; NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:mydaatabase]; NSLog(@"=======%@", [NSBundle mainBundle]); success = [fileManager1 copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error]; if(!success) { NSAssert1(0,@"Failed to create writable database file with Message : '%@'.", [error localizedDescription]); } } 

Answer 1

检查您的.sqlite文件是否添加到您的项目的Build Phases的Copy Bundle Resources 。 如果不存在，请将其添加到您的项目中。

而且，我找不到打开数据库的代码。 所以，在你的ViewController.h文件中，声明Sqlite *database;

在您的ViewController.m文件中，

 -(void)databaseOpen { NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory=[paths objectAtIndex:0]; NSString *myDBnew=[documentsDirectory stringByAppendingPathComponent:@"yourSqliteFile.sqlite"]; database =[[Sqlite alloc]init]; [database open:myDBnew]; NSLog(@"path: %@", myDBnew); NSLog(@"Database opened"); } 

并把它称为任何你想要的[self databaseOpen]; 然后编写你的查询。

另外，你的-(void)createEditableCopyOfDatabaseIfNeeded在你的AppDelegate.m应该看起来像这样：

 - (void)createEditableCopyOfDatabaseIfNeeded { // First, test for existence. BOOL success; NSFileManager *fileManager = [NSFileManager defaultManager]; NSError *error; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:@"yourSqliteFile.sqlite"]; success = [fileManager fileExistsAtPath:writableDBPath]; if (success) return; // The writable database does not exist, so copy the default to the appropriate location. NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"yourSqliteFile.sqlite"]; success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error]; if (!success) { NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]); } } 

在didFinishLaunchingWithOptions:调用-(void)createEditableCopyOfDatabaseIfNeeded didFinishLaunchingWithOptions:

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Override point for customization after application launch. [self createEditableCopyOfDatabaseIfNeeded]; return YES; } 

这应该让你去。

Answer 2

以下是使用SQLite数据库的步骤。

1. 在SQLite中创build你的数据库，添加所需的表结构。 并将其添加到您的应用程序。

2. 现在，进入您的应用程序，从左侧面板中select项目，在中间面板 – >常规 – >链接框架和库（最后一个）添加libsqlite3.0.tbd （这取决于您的Xcode版本）。

3. 现在，在your-object.h定义下面的方法

    #import <sqlite3.h> + (NSString *)getDBPath; + (void)copyDatabaseIfNeeded; + (void)openDatase; 

4. 在your-object.m实现这些

    static sqlite3 *database; #pragma mark - Copy and open databse + (NSString *)getDBPath { NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; return [documentsDir stirngByAppendingPathComponent:@"dbName.sqlite"]; } + (void)copyDatabaseIfNeeded { NSFileManager *fileManager = [NSFileManager defaultManager]; NSError *error; NSString *dbPath = [self getDBPath]; BOOL success = [fileManager fileExistsAtPath:dbPath]; if(!success) { NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"dbName.sqlite"]; success = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error]; if (!success) NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]); } } + (void)openDatase { NSString *dbPath = [self getDBPath]; if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) { NSLog(@"Database Successfully Opened."); } else { NSLog(@"Error in opening database."); } } 

5. 然后在application: didFinishLaunchingWithOptions:中的AppDelegate.m中调用方法application: didFinishLaunchingWithOptions:

    [DataManager copyDatabaseIfNeeded]; 

6. 每当你想用数据库执行任务时，打开它并检查。

用于插入数据库

  + (void)insertData { const char *dbpath = [[self getDBPath] UTF8String]; if (sqlite3_open(dbpath, &database) == SQLITE_OK) { NSString *strSQL = [NSString stringWithFormat:@"INSERT INTO table name………………."]; const char *insertQuery = [strSQL UTF8String]; sqlite3_stmt *insert_stmt; if (sqlite3_prepare_v2(database, insertQuery, -1, &insert_stmt, NULL) == SQLITE_OK) { if (sqlite3_step(insert_stmt) == SQLITE_DONE) { // Code } else { NSLog(@"error"); } } sqlite3_finalize(insert_stmt); sqlite3_close(database); } } 

7.完成….享受与数据库。