IOS development-database-sqlite operation 2

1. Create a single view project, import the FMDatabase library, and import the libsqlite3 system library;

2. ViewController. xib File

3. ViewController. h

@interface ViewController : UIViewController
 
  {    IBOutlet UITextField *_name;    IBOutlet UIImageView *_image;    FMDatabase *_db;}- (IBAction)add:(id)sender;- (IBAction)del:(id)sender;- (IBAction)search:(id)sender;- (IBAction)update:(id)sender;
 

4. ViewController. m

-(Void) viewDidLoad {[super viewDidLoad]; // _ image. userInteractionEnabled = YES; // UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget: self action: @ selector (selectImage)]; // tap. numberOfTapsRequired = 2; // double-click the trigger. By default, click // tap. numberOfTouchesRequired = 2; // press Both fingers at the same time. The default value is [_ image addGestureRecognizer: tap]; [tap release]; // database path NSString * path = [NSString stringWit HFormat: @ "% @/Documents/data. db ", NSHomeDirectory ()]; _ db = [[FMDatabase alloc] initWithPath: path];}-(void) selectImage {UIImagePickerController * ipc = [[UIImagePickerController alloc] init]; ipc. sourceType = UIImagePickerControllerSourceTypePhotoLibrary; // set the image source to ipc. delegate = self; [self presentViewController: ipc animated: YES completion: nil]; // use the modal view to display the selection window [ipc release];} // select image call-(void) image PickerController :( UIImagePickerController *) picker didFinishPickingMediaWithInfo :( NSDictionary *) info {_ image. image = [info objectForKey: Custom]; [self dismissViewControllerAnimated: YES completion: nil];} // click Cancel call-(void) Cancel :( UIImagePickerController *) picker {[self dismissViewControllerAnimated: YES completion: nil];}-(IBAction) add :( id) sender {If (_ name. text = nil | _ image. image = nil) {NSLog (@ "null"); return;} // open the database BOOL res = [_ db open]; if (res = NO) {NSLog (@ "failed to open"); return;} // open successfully // create table res = [_ db executeUpdate: @ "create table if not exists studentss (id integer primary key autoincrement, name, image)"]; if (res = NO) {NSLog (@ "table creation failed "); [_ db close]; return;} // NSNumber NSString NSData // insert NSData * data = UIImagePNGReprese Ntation (_ image. image); res = [_ db executeUpdate: @ "insert into studentss (name, image) values (?,?) ", _ Name. text, data]; if (res = NO) {NSLog (@ "insertion failed");} [_ db close];}-(IBAction) del :( id) sender {BOOL res = [_ db open]; if (res = NO) {NSLog (@ "failed to open"); return;} res = [_ db executeUpdate: @ "delete from studentss where name =? ", _ Name. text]; if (res = NO) {NSLog (@ "delete failed");} [_ db close];}-(IBAction) search :( id) sender {BOOL res = [_ db open]; if (res = NO) {NSLog (@ "failed to open"); return;} FMResultSet * set = [_ db executeQuery: @ "select * from studentss"]; while ([set next]) {int uid = [set intForColumn: @ "id"]; // obtain the field name. // int uid = [set intForColumnIndex: 0]; NSString * name = [set stringForColumnIndex: 1] based on the field index. // NSData * data = [Set dataForColumn: @ "image"]; NSLog (@ "% d --- % @", uid, name) ;}[ _ db close] ;}- (IBAction) update :( id) sender {BOOL res = [_ db open]; if (res = NO) {NSLog (@ "failed to open"); return ;} res = [_ db executeUpdate: @ "update studentss set name = 'bala' where name =? ", _ Name. text]; if (res = NO) {NSLog (@" update failed ");} [_ db close];}