Pangkalan data IOS SQLite
Pangkalan Data SQLite IOS
Pengenalan
Gunakan Sqlite dalam IOS untuk memproses data. Jika anda sudah mengetahui SQL, anda boleh menguasai operasi pangkalan data SQLite dengan mudah.
Instance Steps
1. -> Fail... -> "Pilih kelas Objektif C untuk mencipta fail baharu, klik Seterusnya
4. "sub kelas" ialah NSObject", dan kelas itu dinamakan DBManager
5 6. Kemas kini DBManager. seperti ditunjukkan di bawah
#import <Foundation/Foundation.h>#import <sqlite3.h>@interface DBManager : NSObject{ NSString *databasePath;}+(DBManager*)getSharedInstance;-(BOOL)createDB;-(BOOL) saveData:(NSString*)registerNumber name:(NSString*)name
department:(NSString*)department year:(NSString*)year;-(NSArray*) findByRegisterNumber:(NSString*)registerNumber;@end7. Kemas kini DBManager.m seperti yang ditunjukkan di bawah
#import "DBManager.h"static DBManager *sharedInstance = nil;static sqlite3 *database = nil;static sqlite3_stmt *statement = nil;@implementation DBManager+(DBManager*)getSharedInstance{ if (!sharedInstance) {
sharedInstance = [[super allocWithZone:NULL]init]; [sharedInstance createDB]; } return sharedInstance;}-(BOOL)createDB{ NSString *docsDir; NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0]; // Build the path to the database file
databasePath = [[NSString alloc] initWithString:
[docsDir stringByAppendingPathComponent: @"student.db"]];
BOOL isSuccess = YES; NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: databasePath ] == NO) { const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK) { char *errMsg; const char *sql_stmt = "create table if not exists studentsDetail (regno integer
primary key, name text, department text, year text)";
if (sqlite3_exec(database, sql_stmt, NULL, NULL, &errMsg)
!= SQLITE_OK) {
isSuccess = NO; NSLog(@"Failed to create table"); }
sqlite3_close(database); return isSuccess; } else {
isSuccess = NO; NSLog(@"Failed to open/create database"); } }
return isSuccess;}- (BOOL) saveData:(NSString*)registerNumber name:(NSString*)name
department:(NSString*)department year:(NSString*)year;{ const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK) {
NSString *insertSQL = [NSString stringWithFormat:@"insert into
studentsDetail (regno,name, department, year) values
(\"%d\",\"%@\", \"%@\", \"%@\")",[registerNumber integerValue],
name, department, year];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(database, insert_stmt,-1, &statement, NULL); if (sqlite3_step(statement) == SQLITE_DONE) { return YES; }
else { return NO; }
sqlite3_reset(statement); } return NO;}- (NSArray*) findByRegisterNumber:(NSString*)registerNumber{ const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &database) == SQLITE_OK) { NSString *querySQL = [NSString stringWithFormat: @"select name, department, year from studentsDetail where
regno=\"%@\"",registerNumber];
const char *query_stmt = [querySQL UTF8String]; NSMutableArray *resultArray = [[NSMutableArray alloc]init]; if (sqlite3_prepare_v2(database,
query_stmt, -1, &statement, NULL) == SQLITE_OK) { if (sqlite3_step(statement) == SQLITE_ROW) {
NSString *name = [[NSString alloc] initWithUTF8String: (const char *) sqlite3_column_text(statement, 0)]; [resultArray addObject:name]; NSString *department = [[NSString alloc] initWithUTF8String: (const char *) sqlite3_column_text(statement, 1)]; [resultArray addObject:department]; NSString *year = [[NSString alloc]initWithUTF8String: (const char *) sqlite3_column_text(statement, 2)]; [resultArray addObject:year]; return resultArray; } else{ NSLog(@"Not found"); return nil; }
sqlite3_reset(statement); } } return nil;}8 medan teks
10. Cipta IBAction untuk butang di atas
11 Kemas kini ViewController.h seperti yang ditunjukkan di bawah
#import <UIKit/UIKit.h>#import "DBManager.h"@interface ViewController : UIViewController<UITextFieldDelegate>{ IBOutlet UITextField *regNoTextField; IBOutlet UITextField *nameTextField; IBOutlet UITextField *departmentTextField; IBOutlet UITextField *yearTextField; IBOutlet UITextField *findByRegisterNumberTextField; IBOutlet UIScrollView *myScrollView;}-(IBAction)saveData:(id)sender;-(IBAction)findData:(id)sender;@end12 Kemas kini ViewController.m seperti yang ditunjukkan di bawah
#import "ViewController.h"@interface ViewController ()@end@implementation ViewController- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)
nibBundleOrNil{ self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization } return self;}- (void)viewDidLoad{ [super viewDidLoad]; // Do any additional setup after loading the view from its nib.}- (void)didReceiveMemoryWarning{ [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated.}-(IBAction)saveData:(id)sender{
BOOL success = NO; NSString *alertString = @"Data Insertion failed"; if (regNoTextField.text.length>0 &&nameTextField.text.length>0 &&
departmentTextField.text.length>0 &&yearTextField.text.length>0 ) {
success = [[DBManager getSharedInstance]saveData:
regNoTextField.text name:nameTextField.text department:
departmentTextField.text year:yearTextField.text]; } else{
alertString = @"Enter all fields"; }
if (success == NO) { UIAlertView *alert = [[UIAlertView alloc]initWithTitle:
alertString message:nil delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil]; [alert show]; }}-(IBAction)findData:(id)sender{ NSArray *data = [[DBManager getSharedInstance]findByRegisterNumber:
findByRegisterNumberTextField.text]; if (data == nil) { UIAlertView *alert = [[UIAlertView alloc]initWithTitle: @"Data not found" message:nil delegate:nil cancelButtonTitle: @"OK" otherButtonTitles:nil]; [alert show];
regNoTextField.text = @"";
nameTextField.text =@"";
departmentTextField.text = @"";
yearTextField.text =@""; } else{
regNoTextField.text = findByRegisterNumberTextField.text;
nameTextField.text =[data objectAtIndex:0];
departmentTextField.text = [data objectAtIndex:1];
yearTextField.text =[data objectAtIndex:2]; }}#pragma mark - Text field delegate-(void)textFieldDidBeginEditing:(UITextField *)textField{ [myScrollView setFrame:CGRectMake(10, 50, 300, 200)]; [myScrollView setContentSize:CGSizeMake(300, 350)];}-(void)textFieldDidEndEditing:(UITextField *)textField{ [myScrollView setFrame:CGRectMake(10, 50, 300, 350)];}-(BOOL) textFieldShouldReturn:(UITextField *)textField{
[textField resignFirstResponder]; return YES;}@endOutput
