我是iPhone开发的新手。我使用mac os x中的终端创建了数据库。现在我尝试使用objective- C在iPhone应用程序中以编程方式创建数据库。有人可以告诉我一个很好的网站，我可以查看有效的示例应用程序，是否有任何学习本教程的网站？请有人帮助我。
答案 0 :(得分：14)
NSString *docsDir;
NSArray *dirPaths;
// 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: @"contacts.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 CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT, ADDRESS TEXT, PHONE TEXT)";
if (sqlite3_exec(contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK) {
status.text = @"Failed to create table";
}
sqlite3_close(contactDB);
}
else {
status.text = @"Failed to open/create database";
}
}
[filemgr release];
答案 1 :(得分：3)
#pragma mark - SQLite
-(void)createDatabase
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
databasePath = [[NSString alloc]initWithString:[documentsDirectory stringByAppendingPathComponent:@"timings.db"]];
if ([[NSFileManager defaultManager] fileExistsAtPath:databasePath] == FALSE)
{
if (sqlite3_open([databasePath UTF8String], &timingsDatabase) == SQLITE_OK)
{
const char *sqlStatement = "CREATE TABLE IF NOT EXISTS TIMINGS (ID INTEGER PRIMARY KEY AUTOINCREMENT, TIMESTAMP TEXT, TIMING TEXT)";
char *error;
sqlite3_exec(timingsDatabase, sqlStatement, NULL, NULL, &error);
sqlite3_close(timingsDatabase);
}
}
}
-(void)storeTiming
{
if (sqlite3_open([databasePath UTF8String], &timingsDatabase) == SQLITE_OK)
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"HH:mm:ss.SSS"];
NSString *insertStatement = [NSString stringWithFormat:@"INSERT INTO TIMINGS (TIMESTAMP, TIMING) VALUES (\"%@\", \"%@\")", [dateFormatter stringFromDate:startDate], stopWatchLabel.text];
char *error;
sqlite3_exec(timingsDatabase, [insertStatement UTF8String], NULL, NULL, &error);
sqlite3_close(timingsDatabase);
[dateFormatter release];
}
}
-(void)getTimings
{
if (sqlite3_open([databasePath UTF8String], &timingsDatabase) == SQLITE_OK)
{
NSString *queryStatement = [NSString stringWithFormat:@"SELECT TIMESTAMP, TIMING FROM TIMINGS"];
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(timingsDatabase, [queryStatement UTF8String], -1, &statement, NULL) == SQLITE_OK)
{
while (sqlite3_step(statement) == SQLITE_ROW) {
NSLog(@"Timestamp: %s Timing: %s", sqlite3_column_text(statement, 0), sqlite3_column_text(statement, 1));
}
sqlite3_finalize(statement);
sqlite3_close(timingsDatabase);
}
}
}
检查以下示例：
答案 2 :(得分：2)
在xcode中创建Sqlite数据库
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
[self createDb];
return YES;
}
-(void)createDb
{
NSArray *dir=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *dbPath=[NSString stringWithFormat:@"%@/userDb.sqlite",[dir lastObject]];
sqlite3 *db;
NSFileManager *fm=[NSFileManager new];
if([fm fileExistsAtPath:dbPath isDirectory:nil])
{
NSLog(@"Database already exists..");
return;
}
if (sqlite3_open([dbPath UTF8String],&db)==SQLITE_OK)
{
const char *query="create table user (userName VARCHAR(20),userAdd VARCHAR(20), userPass VARCHAR(20))";
if (sqlite3_exec(db, query, NULL, NULL, NULL)==SQLITE_OK)
{
NSLog(@"User table created successfully..");
}else
{
NSLog(@"User table creation failed..");
}
}else
{
NSLog(@"Open table failed..");
}
sqlite3_close(db);
}
答案 3 :(得分：1)
如果你想使用数据库数据持久性查看CoreData它是一个很好的资源，用于存储应用程序的大量数据，请记住，虽然CoreData不是数据库。
您可以在iOS平台上轻松使用SQLite，但是您没有像使用CoreData那样提供可视化工具来开发它
如果要存储少量数据，请将信息存储到plist中。
如果要存储一些字符串，整数或bool，则应使用NSUserDefaults
如果没有更多信息，我无法确定哪种方法最适合您
其他资源：
答案 4 :(得分：1)
要为您的iPhone应用程序创建数据库有点冗长，但它有很多步骤，但它很简单：
首先，你应该下载mozilla fire fox并下载它的附加组件，你可以通过单击Tools Option找到sqlite数据库选项。您可以创建包含列和行的新Databse文件。创建数据库文件的过程非常简单，之后您可以将该文件包含在X代码项目中。
例如： - 就像您通常包含在Xcode项目中的图像一样。 / p>
之后写下面的代码对我来说很好用:)）
在你的。 m文件写下面的sqlite代码
#import "YourHeaderFile"
static sqlite3 *database = nil;
static sqlite3_stmt *addStmt = nil;
static sqlite3_stmt *updateStmt = nil;
@implementation 'YourImplementClass'
- (NSString *) getDBPath {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
return [documentsDir stringByAppendingPathComponent:@"YourDataBaseFileName.sqlite"];
}
- (void) insertValueToDatabase {
NSString *dbPath =[self getDBPath];
NSString *select_Meal = dummy_select_Meal;
NSString *dateTime = dummy_date_Time;
NSString *location = dummy_location;
NSString *mealItem = dummy_mealItem;
if (sqlite3_open([dbPath UTF8String], &database) == SQLITE_OK) {
const char *sqlDB = "Insert into iHad(Mealtype,DateAndTime,Location,Mealitem) VALUES (?,?,?,?)";
if(sqlite3_prepare_v2(database, sqlDB, -1, &addStmt, NULL) != SQLITE_OK)
NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database));
sqlite3_bind_text(addStmt, 1, [select_Meal UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(addStmt, 2, [dateTime UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(addStmt, 3, [location UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(addStmt, 4, [mealItem UTF8String], -1, SQLITE_TRANSIENT);
if(SQLITE_DONE != sqlite3_step(addStmt))
NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(database));
//else
//SQLite provides a method to get the last primary key inserted by using sqlite3_last_insert_rowid
//coffeeID = sqlite3_last_insert_rowid(database);
//Reset the add statement.
sqlite3_reset(addStmt);
}
else
sqlite3_close(database);
}
对于保存，你可以创建一个这样的方法
-(void)saveButtonClick
{
if (![dummy_select_Meal length] || ![dummy_mealItem length])
{
UIAlertView *alert = [[UIAlertView alloc] init];
[alert setTitle:@"Select Meal Type/Meal Item"];
[alert setDelegate:self];
[alert addButtonWithTitle:@"Ok"];
[alert show];
[alert release];
}
else
{
indicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(30,30,50,50)];
indicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;//UIActivityIndicatorViewStyleWhiteLarge;//
[self insertValueToDatabase];-----------------------> To insert data into data base
iHadAppDelegate *delegate = [[UIApplication sharedApplication]delegate];
[delegate readMealsFromDatabase];
[rootController reloadTable_SaveButton];
}
[rootController showTablePopupAction:nil];
}
如果您有任何问题，请回复我，我会帮助您：）
答案 5 :(得分：0)
在didFinishLaunchingWithOptions：
调用此函数 -(void)createdb
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *dbPath = [documentsDirectory stringByAppendingPathComponent:@"emp.sqlite"];
NSURL *dbURL = [NSURL fileURLWithPath:dbPath];
// copy a database from the bundle if not present
// on disk
NSFileManager *fm = [NSFileManager defaultManager];
if (![fm fileExistsAtPath:dbPath])
{
NSURL *bundlePath = [[NSBundle mainBundle] URLForResource:@"emp" withExtension:@"sqlite"];
NSError *error = nil;
if (!bundlePath || ![fm copyItemAtURL:bundlePath toURL:dbURL error:&error])
{
NSLog(@"error copying database from bundle: %@", error);
}
}
else
{
NSLog(@"Success in Copy file");
}
}
答案 6 :(得分：0)
在记忆警告后调用此功能。
- （IBAction）saveData：（UIButton *）sender {
sqlite3_stmt *statement;
const char *dbPath = [databasePath UTF8String];
if(sqlite3_open(dbPath, &contactDB)== SQLITE_OK){
NSString *insertSQL = [NSString stringWithFormat:@"INSERT INTO CONTACTS(NAME,ADDRESS,PHONE)VALUES(\"%@\",\"%@\",\"%@\")",_name.text,_address.text,_phoneNo.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 = @"";
_phoneNo.text = @"";
}else{
_status.text = @"Failed to add contact";
}
sqlite3_finalize(statement);
sqlite3_close(contactDB);
}
}