Iphone 如何以编程方式创建sqlite数据库？

我是iPhone开发新手。我已经使用MacOSX中的终端创建了数据库。现在，我正在尝试使用

objective-C

在iPhone应用程序中以编程方式创建数据库。有人能告诉我一个好的网站，在那里我可以查看已经运行的示例应用程序，并且有学习教程的网站吗？请有人帮帮我。

发件人：

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如果您想使用数据库进行数据持久化，请查看它是为应用程序存储大量数据的良好资源，请记住，尽管CoreData不是数据库

您可以在iOS平台上非常轻松地使用SQLite，但并没有像使用CoreData那样提供可视化工具来开发它

如果您存储的数据量较小，请考虑将信息存储到plist中

如果要存储一些字符串、int或bool，则应使用NSUserDefaults

如果没有更多的信息，我无法确定什么是最适合你的方法

其他资源：

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为iPhone应用程序创建数据库有点长，但步骤很多，但非常简单：

首先，您应该下载mozilla fire fox并下载其附加组件，您可以通过单击工具选项找到sqlite数据库选项。您可以创建一个包含列和行的新数据库文件。创建一个数据库文件只是一个简单的过程，之后您可以将该文件包含到您的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

之后，编写以下代码，这对我来说很好：）

在你的房间里。m文件编写以下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); 

}

为了节省，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：）

检查以下示例：

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在didFinishLaunchingWithOptions处调用此函数：

  -(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");
       }
  }

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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);

}

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在memmory警告后调用此函数

-（iAction）保存数据：（UIButton*）发送方{

---

}

我建议你在谷歌上搜索。搜索引擎不应出现堆栈溢出。由于您是堆栈溢出新手，所以我没有标记向下投票。请先阅读

dbpath==databasePath

<代码>联系人数据库声明在哪里？

  -(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");
       }
  }

- (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);

}

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);

}