我正在iphone中开发一个应用程序，我是iphone的新手。 请告诉我使用sqlite在iphone中打开/关闭/更新/删除数据库记录的代码？
此致 VIJAYA
答案 0 :(得分：4)
在.h文件中
- (void)createEditableCopyOfDatabaseIfNeeded;
+ (sqlite3 *) getNewDBConnection;
在appdelegate.m方法的didFinishLaunching中添加以下代码：
[self createEditableCopyOfDatabaseIfNeeded];
- (void)createEditableCopyOfDatabaseIfNeeded {
NSLog(@"Creating editable copy of database");
// 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:@"Scores.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:@"Scores.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
if (!success) {
NSAssert1(0, @"Failed to create writable database file with message ‘%@’.", [error localizedDescription]);
}
}
+ (sqlite3 *) getNewDBConnection {
sqlite3 *newDBconnection;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"Scores.sqlite"];
// Open the database. The database was prepared outside the application.
if (sqlite3_open([path UTF8String], &newDBconnection) == SQLITE_OK) {
NSLog(@"Database Successfully Opened ");
} else {
NSLog(@"Error in opening database ");
}
return newDBconnection;
}
在你的视图控制器中调用插入方法等。这里我调用了一个方法，它从表
中获取数据sqlite3* db =[iMemory_SharpenerAppDelegate getNewDBConnection];
sqlite3_stmt *statement = nil;
const char *sql = "select * from HighScore";
if(sqlite3_prepare_v2(db, sql, -1, &statement, NULL)!=SQLITE_OK) {
NSAssert1(0,@"error prepearing statement",sqlite3_errmsg(db));
} else {
while (sqlite3_step(statement)==SQLITE_ROW) {
//dt= [[NSString alloc]initWithUTF8String:(char *)sqlite3_column_text(statement, 2)];
dt = [NSString stringWithFormat:@"%s",(char *)sqlite3_column_text(statement, 0)];
//dt = [NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, 2)];
NSLog(@"%@score==",dt);
[nmber addObject:dt];
}
}
sqlite3_finalize(statement);
sqlite3_close(db);
答案 1 :(得分：1)
阅读website上的sqlite文档。他们有API参考和教程。您需要在XCode中使用的只是将libsqlite3.dylib添加到引用的框架中。
答案 2 :(得分：1)
以下是从iOS连接SQLite的示例代码:(插入数据） 来源：http://sickprogrammersarea.blogspot.in/2014/03/sqlite-in-ios-using-objective-c.html
#import "sqlLiteDemoViewController.h"
@interface sqlLiteDemoViewController (){
UILabel *lblName;
UILabel *lblRoll;
UILabel *lblAge;
UITextField *txtName;
UITextField *txtroll;
UISlider *sldAge;
}
@end
@implementation sqlLiteDemoViewController
- (void)viewDidLoad
{
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"]];
NSLog(@"%@",_databasePath);
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt ="CREATE TABLE IF NOT EXISTS STUDENT (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ROLL TEXT, AGE TEXT)";
if (sqlite3_exec(_contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
NSLog(@"Failed to create table");
}
sqlite3_close(_contactDB);
NSLog(@"Connection Successful");
} else {
NSLog(@"Failed to open/create database");
}
}
UITapGestureRecognizer *tapScroll = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapped)];
[self.view addGestureRecognizer:tapScroll];
[super viewDidLoad];
lblName = [[UILabel alloc] initWithFrame:CGRectMake(10, 30, 100, 50)];
lblName.backgroundColor = [UIColor clearColor];
lblName.textColor=[UIColor blackColor];
lblName.text = @"Name";
[self.view addSubview:lblName];
lblRoll = [[UILabel alloc] initWithFrame:CGRectMake(10, 80, 100, 50)];
lblRoll.backgroundColor = [UIColor clearColor];
lblRoll.textColor=[UIColor blackColor];
lblRoll.text = @"Roll no";
[self.view addSubview:lblRoll];
lblAge = [[UILabel alloc] initWithFrame:CGRectMake(10, 130, 100, 50)];
lblAge.backgroundColor = [UIColor clearColor];
lblAge.textColor=[UIColor blackColor];
lblAge.text = @"Age";
[self.view addSubview:lblAge];
txtName = [[UITextField alloc] initWithFrame:CGRectMake(80, 40, 200, 40)];
txtName.borderStyle = UITextBorderStyleRoundedRect;
txtName.font = [UIFont systemFontOfSize:15];
txtName.placeholder = @"Specify Name";
txtName.autocorrectionType = UITextAutocorrectionTypeNo;
txtName.keyboardType = UIKeyboardTypeDefault;
txtName.returnKeyType = UIReturnKeyDone;
txtName.clearButtonMode = UITextFieldViewModeWhileEditing;
txtName.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
txtName.delegate = self;
[self.view addSubview:txtName];
txtroll = [[UITextField alloc] initWithFrame:CGRectMake(80, 90, 200, 40)];
txtroll.borderStyle = UITextBorderStyleRoundedRect;
txtroll.font = [UIFont systemFontOfSize:15];
txtroll.placeholder = @"Specify Roll";
txtroll.autocorrectionType = UITextAutocorrectionTypeNo;
txtroll.keyboardType = UIKeyboardTypeNumberPad;
txtroll.returnKeyType = UIReturnKeyDone;
txtroll.clearButtonMode = UITextFieldViewModeWhileEditing;
txtroll.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
txtroll.delegate = self;
[self.view addSubview:txtroll];
CGRect frame = CGRectMake(80.0, 140.0, 200.0, 40.0);
sldAge= [[UISlider alloc] initWithFrame:frame];
[sldAge setBackgroundColor:[UIColor clearColor]];
sldAge.minimumValue = 0;
sldAge.maximumValue = 30;
sldAge.continuous = YES;
sldAge.value = 15.0;
[self.view addSubview:sldAge];
UIButton *subButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
subButton.frame = CGRectMake(80.0, 200.0, 80.0, 30.0);
[subButton setTitle:@"Store" forState:UIControlStateNormal];
subButton.backgroundColor = [UIColor clearColor];
[subButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal ];
[subButton addTarget:self action:@selector(store:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:subButton];
UIButton *srchButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
srchButton.frame = CGRectMake(200.0, 200.0, 80.0, 30.0);
[srchButton setTitle:@"Search" forState:UIControlStateNormal];
srchButton.backgroundColor = [UIColor clearColor];
[srchButton setTitleColor:[UIColor blackColor] forState:UIControlStateNormal ];
[srchButton addTarget:self action:@selector(find:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:srchButton];
}
- (void)tapped {
[self.view endEditing:YES];
}
-(void)store:(id)sender{
@try{
NSLog(@"store called");
sqlite3_stmt *statement;
const char *dbpath = (const char *)[_databasePath UTF8String];
NSString *age=[NSString stringWithFormat:@"%g", sldAge.value];
NSLog(@"Age is %@",age);
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
NSString *insertSQL = [NSString stringWithFormat:
@"INSERT INTO STUDENT (name, roll , age) VALUES (\"%@\", \"%@\", \"%@\")",
txtName.text, txtroll.text, age];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(_contactDB, insert_stmt,
-1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
NSLog(@"Insertion Successful");
} else {
NSLog(@"Insertion Failure");
}
sqlite3_finalize(statement);
sqlite3_close(_contactDB);
}
}@catch (NSException *e) {
NSLog(@"Exception : %s",sqlite3_errmsg(_contactDB));
}
}
- (void) find:(id)sender
{
const char *dbpath = [_databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:@"SELECT roll, age FROM STUDENT WHERE name=\"%@\"",txtName.text];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(_contactDB,query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
if (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *roll = [[NSString alloc]initWithUTF8String:(const char *) sqlite3_column_text(statement, 0)];
txtroll.text = roll;
NSString *age = [[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 1)];
sldAge.value = [age floatValue];
NSLog(@"Match found");
} else {
NSLog(@"Match found");
txtroll.text = @"";
sldAge.value = 0.0;
}
sqlite3_finalize(statement);
}
sqlite3_close(_contactDB);
}
}
答案 3 :(得分：0)
ViewController.h
#import <UIKit/UIKit.h>
#import "sqlite3.h"
@interface ViewController
{
IBOutlet UITextField *no;
UITextField *name,*address;
IBOutlet UIButton *save,*update,*del,*clear,*Find,*showdata;
sqlite3 *contactDB;
IBOutlet UILabel *status;
}
@property (strong, nonatomic) IBOutlet UITextField *no;
@property (strong, nonatomic) IBOutlet UITextField *name;
@property (strong, nonatomic) IBOutlet UITextField *address;
@property (retain, nonatomic) IBOutlet UILabel *status;
- (IBAction)SaveData:(id)sender;
- (IBAction)FindData:(id)sender;
- (IBAction)UpdateData:(id)sender;
- (IBAction)DeleteData:(id)sender;
- (IBAction)ClearData:(id)sender;
- (IBAction)ShowData:(id)sender;
@end
ViewController.m
#import "ViewController.h"
#import "ShowRecord.h"
@interface ViewController ()
{
NSString *docsDir;
NSArray *dirPaths;
NSString *databasePath;
}
@end
@implementation ViewController
@synthesize name, address,status,no;
- (void)viewDidLoad
{
[self LoadDB];
[status setHidden:TRUE];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
- (void)viewDidUnload {
self.name = nil;
self.address = nil;
self.status = nil;
}
-(void)LoadDB
{
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES);
docsDir = [dirPaths objectAtIndex:0];
// Build the path to the database file
databasePath = [[NSString alloc]initWithString: [docsDir stringByAppendingPathComponent:@"student.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if ([filemgr fileExistsAtPath: databasePath ] == NO)
{
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt = "CREATE TABLE IF NOT EXISTS stud (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT)";
if (sqlite3_exec(contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
status.text = @"Failed to create table";
}
else
{
status.text = @"success Created table";
}
sqlite3_close(contactDB);
}
else
{
status.text = @"Failed to open/create database";
}
}
}
- (IBAction)SaveData:(id)sender
{
[status setHidden:false];
sqlite3_stmt *statement;
const char *dbpath = [databasePath UTF8String];
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSString *insertSQL = [NSString stringWithFormat: @"INSERT INTO stud (name, address) VALUES (\"%@\", \"%@\")", name.text, address.text];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(contactDB, insert_stmt, -1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
status.text = @"Contact added";
name.text = @"";
address.text = @"";
}
else
{
status.text = @"Failed to add contact";
}
sqlite3_finalize(statement);
sqlite3_close(contactDB);
}
}
- (IBAction)UpdateData:(id)sender
{
[status setHidden:false];
sqlite3_stmt *statement;
const char *dbpath=[databasePath UTF8String];
if(sqlite3_open(dbpath, &contactDB)==SQLITE_OK)
{
NSString *updateSQl=[NSString stringWithFormat:@"update stud set name=\"%@\",address=\"%@\" where id=\"%@\" ",name.text,address.text,no.text];
const char *update_stmt=[updateSQl UTF8String];
sqlite3_prepare_v2(contactDB, update_stmt, -1, &statement, NULL);
if (sqlite3_step(statement)==SQLITE_DONE)
{
status.text=@"Record Updated";
name.text=@"";
address.text=@"";
no.text=@"";
}
else
{
status.text=@"Record Not Updated";
}
}
}
- (IBAction)DeleteData:(id)sender
{
[status setHidden:false];
sqlite3_stmt *statement;
const char *dbpath=[databasePath UTF8String];
if (sqlite3_open(dbpath, &contactDB)==SQLITE_OK) {
NSString *deleteSql=[NSString stringWithFormat:@"delete from stud where id=\"%@\"",no.text];
const char *delete_stmt=[deleteSql UTF8String];
sqlite3_prepare_v2(contactDB, delete_stmt, -1, &statement, NULL);
if(sqlite3_step(statement)==SQLITE_DONE)
{
status.text=@"Record Deleted";
name.text=@"";
address.text=@"";
no.text=@"";
}
else
{
status.text=@"Record Not Deleted ";
}
}
}
- (IBAction)ClearData:(id)sender
{
name.text=@"";
no.text=@"";
address.text=@"";
}
- (IBAction)ShowData:(id)sender
{
ShowRecord *showrecord=[[ShowRecord alloc]initWithNibName:@"ShowRecord" bundle:nil];
[self. pushViewController:showrecord animated:YES];
// ShowRecord *vc1 = [[ShowRecord alloc] initWithNibName:@"ViewControllerNext" bundle:nil];
//[self.navigationController pushViewController:vc1 animated:YES];
}
- (IBAction)FindData:(id)sender
{
[status setHidden:false];
const char *dbpath = [databasePath UTF8String];
sqlite3_stmt *statement;
if (sqlite3_open(dbpath, &contactDB) == SQLITE_OK)
{
NSString *querySQL = [NSString stringWithFormat:
@"SELECT name,address FROM stud WHERE id=\"%@\"",
no.text];
const char *query_stmt = [querySQL UTF8String];
if (sqlite3_prepare_v2(contactDB,
query_stmt, -1, &statement, NULL) == SQLITE_OK)
{
if (sqlite3_step(statement) == SQLITE_ROW)
{
NSString *namefield=[[NSString alloc]initWithUTF8String:(const char *)sqlite3_column_text(statement, 0)];
NSString *addressField = [[NSString alloc]
initWithUTF8String:
(const char *) sqlite3_column_text(statement, 1)];
name.text=namefield;
address.text = addressField;
status.text = @"Record Found";
}
else
{
status.text = @"Record Not Found";
address.text = @"";
name.text=@"";
}
sqlite3_finalize(statement);
}
sqlite3_close(contactDB);
}
}
@end