如何将数据从SQlite显示到iPhone应用程序的表视图
我正在使用SQlite3编写Xcode 4.3中的iPhone项目，SQlite和Xcode之间的连接已经完成，现在我想将我的数据显示到一个表视图（三个视图）和它的只读！ 所以我有主表视图，select原始 – >采取第二个视图，并从数据库中加载其他数据select原始 – >采取细节视图显示长文本和图像！
任何帮助赞赏。
AppDelegate.h
#import "AppDelegate.h" #import "MasterViewController.h" @implementation AppDelegate @synthesize window = _window; @synthesize navigationController = _navigationController; - (void)dealloc { [_window release]; [_navigationController release]; [super dealloc]; } - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { self.window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease]; // Override point for customization after application launch. NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; NSString *dbPath = [documentsDir stringByAppendingPathComponent:@"cities.sqlite"]; NSFileManager *fileManager = [NSFileManager defaultManager]; BOOL success = [fileManager fileExistsAtPath:dbPath]; if (success) { NSLog(@"we have the database"); } else { NSLog(@"we have no database"); NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"cities.sqlite"]; BOOL moved = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:nil]; if (moved) { NSLog(@"database copied"); } } MasterViewController *masterViewController = [[[MasterViewController alloc] initWithNibName:@"MasterViewController" bundle:nil] autorelease]; self.navigationController = [[[UINavigationController alloc] initWithRootViewController:masterViewController] autorelease]; self.window.rootViewController = self.navigationController; [self.window makeKeyAndVisible]; return YES; } MasterViewController.h
#import <UIKit/UIKit.h> #import <sqlite3.h> @class DetailViewController; @interface MasterViewController : UITableViewController { NSMutableArray *cities; } @property (strong, nonatomic) DetailViewController *detailViewController; @end
MasterViewController.m
- (void)viewDidLoad { [super viewDidLoad]; students = [[NSMutableArray alloc] init]; countries = [[NSMutableArray alloc] init]; // Do any additional setup after loading the view, typically from a nib. self.navigationItem.leftBarButtonItem = self.editButtonItem; UIBarButtonItem *addButton = [[[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(insertNewObject:)] autorelease]; self.navigationItem.rightBarButtonItem = addButton; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDir = [paths objectAtIndex:0]; NSString *dbPath = [documentsDir stringByAppendingPathComponent:@"cities.sqlite"]; sqlite3 *database; if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) { const char *sqlStatement = "select * from cities_info"; sqlite3_stmt *compileStatement; if (sqlite3_prepare_v2(database, sqlStatement, -1, &compileStatement, NULL) == SQLITE_OK) { while (sqlite3_step(compileStatement) == SQLITE_ROW) { NSLog(@"one record"); NSString *cityName = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compileStatement, 1)]; [cities addObject:cityName]; } NSLog(@"cities: %@",cities); } } else { NSLog(@"error in database"); } }
大段引用
我build议SQLite轻包装 – 请参阅https://github.com/JohnGoodstadt/EasySQLite
这将允许：
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return _personTable.rows.count; }
和
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { ... NSArray* row= _personTable.rows[indexPath.row]; cell.textLabel.text = row[[_personTable colIndex:@"lastname"]]; ...
通过使用代表SQL表的iVar进行设置：
self.personTable = [_db ExecuteQuery:@"SELECT firstname , lastname , age , salary FROM person"];
和一个DB连接iVar传递你的SQL文件名：
self.db = [DBController sharedDatabaseController:@"DataTable.sqlite"];
首先，我build议使用FMDB ，这是一个围绕sqlite3的Objective-C包装器。 其次，我会创build一个具有共享实例的自定义数据访问对象，如下所示：
@interface MyDatabaseDAO : NSObject @property (nonatomic, strong) FMDatabase *database; @end @implementation MyDatabaseDAO @synthesize database = _database; + (MyDatabaseDAO *)instance { static MyDatabaseDAO *_instance = nil; @synchronized (self) { if (_instance == nil) { _instance = [[self alloc] init]; } } return _instance; } - (id)init { self.database = [FMDatabase databaseWithPath:myDatabasePath]; [self.database open]; } - (void)dealloc { [self.database close]; } @end
这个DAO必须有3个访问方法：一个用于数据库中的每个数据对象。 因为你没有具体的东西，所以我没有任何特定的属性。
- (NSArray *)retrieveAllFirstViewItems { NSMutableArray *items = [NSMutableArray array]; FMResultSet *resultSet = [FMDBDatabase.database executeQuery:@"SELECT * FROM myFirstViewItemTable"]; while ([resultSet next]) { // extract whatever data you want from the resultset NSString *name = [resultSet stringForColumn:@"name"] [items addObject:name]; } [resultSet close]; return items; } - (MySecondViewItem *)retrieveSecondViewItemFromIndexPath:(NSIndexPath *)indexPath { FMResultSet *resultSet = [FMDBDatabase.database executeQuery:@"SELECT * FROM mySecondViewItemTable WHERE pid = ?", [indexPath indexAtPosition:0]]; if ([resultSet next]) { // extract whatever data you want from the resultset NSString *name = [resultSet stringForColumn:@"name"] MySecondViewItem *mySecondViewItem = [[MySecondViewItem alloc] initWithName:name withPID:[indexPath indexAtPosition:0]]; [resultSet close]; return mySecondViewItem; } else { return nil; } } - (MyThirdViewItem *)retrieveThirdViewItemFromIndexPath:(NSIndexPath *)indexPath { FMResultSet *resultSet = [FMDBDatabase.database executeQuery:@"SELECT * FROM mySecondViewItemTable WHERE pid = ?", [indexPath indexAtPosition:1]]; if ([resultSet next]) { // extract whatever data you want from the resultset NSString *name = [resultSet stringForColumn:@"name"] MyThirdViewItem *myThirdViewItem = [[MyThirdViewItem alloc] initWithName:name withPID:[indexPath indexAtPosition:1]]; [resultSet close]; return myThirdViewItem; } else { return nil; } }
由于它是只读的，所以这些都是必需的方法。 在你的第一个UITableView中，只需要实现方法：
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { MySecondViewItem *mySecondViewItem = [[MyDatabaseDAO instance] retrieveSecondViewItemFromIndexPath:indexPath]; //instantiate a view from this item and use [UINavigationController pushViewController:animated:] to navigate to it }
剩下的只是以某种方式在视图中显示数据对象。 我build议尽可能多地在数据访问对象中进行数据检索，以便视图控制器可以读取数据对象的属性，而不必担心后端。
这里的所有都是它的！ 我希望这有助于