/Users/apple/Library/Application Support/iPhone Simulator/6.0/Applications

 /Users/用戶名/資源庫/Application Support/iPhone Simulator/6.1/Applications

 NSString *home = NSHomeDirectory();

NSString *home = NSHomeDirectory();
NSString *documents = [home stringByAppendingPathComponent:@"Documents"];
// 不建議采用，因?yàn)樾掳姹镜牟僮飨到y(tǒng)可能會(huì)修改目錄名

// NSUserDomainMask 代表從用戶文件夾下找  
// YES 代表展開路徑中的波浪字符“~”
NSArray *array = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, NO);
// 在iOS中，只有一個(gè)目錄跟傳入的參數(shù)匹配，所以這個(gè)集合里面只有一個(gè)元素
NSString *documents = [array objectAtIndex:0];

 NSString *tmp= NSTemporaryDirectory();

// 將數(shù)據(jù)封裝成字典 
NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setObject:@"15013141314" forKey:@"phone"];
[dict setObject:@"27" forKey:@"age"];
// 將字典持久化到Documents/stu.plist文件中
[dict writeToFile:path atomically:YES];

// 讀取Documents/stu.plist的內(nèi)容，實(shí)例化NSDictionary
NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:path];
NSLog(@"phone:%@", [dict objectForKey:@"phone"]);
NSLog(@"age:%@", [dict objectForKey:@"age"]);

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:@"Cat" forKey:@"username"];
[defaults setFloat:14.0f forKey:@"text_size"];
[defaults setBool:YES forKey:@"auto_login"];

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSString *username = [defaults stringForKey:@"username"];
float textSize = [defaults floatForKey:@"text_size"];
BOOL autoLogin = [defaults boolForKey:@"auto_login"];

 [defaults synchornize];

NSString *path = [NSString stringWithFormat:@"Documents/array.archive"];
NSArray *array = [NSArray arrayWithObjects:@"a",@"b",nil];
[NSKeyedArchiver archiveRootObject:array toFile:path];

 NSArray *array = [NSKeyedUnarchiver unarchiveObjectWithFile:path];

@interface Person : NSObject <NSCoding>
@property(nonatomic,copy) NSString *name;
@property(nonatomic,assign) int age;
@property(nonatomic,assign) float height;@end

 @implementation Person
-(void)encodeWithCoder:(NSCoder*)encoder{  
 [encoder encodeObject:self.name forKey:@"name"];  
 [encoder encodeInt:self.age forKey:@"age"];  
 [encoder encodeFloat:self.height forKey:@"height"];
}
-(id)initWithCoder:(NSCoder*)decoder {  
 self.name= [decoder decodeObjectForKey:@"name"];  
 self.age= [decoder decodeIntForKey:@"age"];  
 self.height= [decoder decodeFloatForKey:@"height"];  
 return self;
}

 // 歸檔(編碼)
 Person *person = [[Person alloc] init];
 person.name = @"JN";
 person.age = 22;
 person.height = 1.63f;
 [NSKeyedArchiver archiveRootObject:person toFile:path];

 // 恢復(fù)(解碼)
 Person *person = [NSKeyedUnarchiver unarchiveObjectWithFile:path];
@end

// 新建一塊可變數(shù)據(jù)區(qū)
NSMutableData *data = [NSMutableData data];
// 將數(shù)據(jù)區(qū)連接到一個(gè)NSKeyedArchiver對(duì)象
NSKeyedArchiver *archiver = [[[NSKeyedArchiver alloc] initForWritingWithMutableData:data] autorelease];
// 開始存檔對(duì)象，存檔的數(shù)據(jù)都會(huì)存儲(chǔ)到NSMutableData中
[archiver encodeObject:person1 forKey:@"person1"];
[archiver encodeObject:person2 forKey:@"person2"];
// 存檔完畢(一定要調(diào)用這個(gè)方法)
[archiver finishEncoding];
// 將存檔的數(shù)據(jù)寫入文件
[data writeToFile:path atomically:YES];

// 從文件中讀取數(shù)據(jù)
NSData *data = [NSData dataWithContentsOfFile:path];
// 根據(jù)數(shù)據(jù)，解析成一個(gè)NSKeyedUnarchiver對(duì)象
NSKeyedUnarchiver *unarchiver = [[NSKeyedUnarchiver alloc] initForReadingWithData:data];
Person *person1 = [unarchiver decodeObjectForKey:@"person1"];
Person *person2 = [unarchiver decodeObjectForKey:@"person2"];
// 恢復(fù)完畢[unarchiver finishDecoding];

// 臨時(shí)存儲(chǔ)person1的數(shù)據(jù)
NSData *data = [NSKeyedArchiver archivedDataWithRootObject:person1];
// 解析data，生成一個(gè)新的Person對(duì)象
Student *person2 = [NSKeyedUnarchiver unarchiveObjectWithData:data];
// 分別打印內(nèi)存地址
NSLog(@"person1:%@", person1); // person1:0x8d3ed10>
NSLog(@"person2:%@", person2); // person2:0x8d3e2f0>

create table if not exists t_student (id integer, name text, age inetger, score real) ;

drop table if exists t_student;

insert into t_student (name, age) values ('JN', 22) ;

pupdate t_student set name = 'jack', age = 20 ;

delete from t_student;

// 將t_student表中年齡大于10 并且 姓名不等于jack的記錄，年齡都改為 5 
update t_student set age = 5 where age > 10 and name != ‘jack' ; 
// 刪除t_student表中年齡小于等于10 或者 年齡大于30的記錄 
delete from t_student where age <= 10 or age > 30 ;

select * from t_student where age > 10 ; // 條件查詢條件語句:

// path為：~/Documents/person.db
sqlite3 *db;int result = sqlite3_open([path UTF8String], &db);

char *errorMsg; // 用來存儲(chǔ)錯(cuò)誤信息
char *sql = "create table if not exists t_person(id integer primary key autoincrement, name text, age integer);";
int result = sqlite3_exec(db, sql, NULL, NULL, &errorMsg);

1.打開數(shù)據(jù)庫
int sqlite3_open(  
const char *filename,  // 數(shù)據(jù)庫的文件路徑  
sqlite3 **ppDb     // 數(shù)據(jù)庫實(shí)例
);
2.執(zhí)行任何SQL語句
int sqlite3_exec(  
sqlite3*,        // 一個(gè)打開的數(shù)據(jù)庫實(shí)例  
const char *sql,              // 需要執(zhí)行的SQL語句  
int (*callback)(void*,int,char**,char**), // SQL語句執(zhí)行完畢后的回調(diào)  
void *,                  // 回調(diào)函數(shù)的第1個(gè)參數(shù)  
char **errmsg               // 錯(cuò)誤信息
);
3.檢查SQL語句的合法性（查詢前的準(zhǔn)備）
int sqlite3_prepare_v2(
  sqlite3 *db,      // 數(shù)據(jù)庫實(shí)例  
const char *zSql,    // 需要檢查的SQL語句  
int nByte,       // SQL語句的最大字節(jié)長度  
sqlite3_stmt **ppStmt, // sqlite3_stmt實(shí)例，用來獲得數(shù)據(jù)庫數(shù)據(jù)  
const char **pzTail
);
4.查詢一行數(shù)據(jù)
int sqlite3_step(
sqlite3_stmt*); // 如果查詢到一行數(shù)據(jù)，就會(huì)返回SQLITE_ROW
5.利用stmt獲得某一字段的值（字段的下標(biāo)從0開始）
double sqlite3_column_double(sqlite3_stmt*, int iCol); // 浮點(diǎn)數(shù)據(jù)
int sqlite3_column_int(sqlite3_stmt*, int iCol); // 整型數(shù)據(jù)
sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); // 長整型數(shù)據(jù)
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); // 二進(jìn)制文本數(shù)據(jù)
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); // 字符串?dāng)?shù)據(jù)

// 從應(yīng)用程序包中加載模型文件 
NSManagedObjectModel *model = [NSManagedObjectModel mergedModelFromBundles:nil];
// 傳入模型，初始化
NSPersistentStoreCoordinator NSPersistentStoreCoordinator *psc = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:model];
// 構(gòu)建SQLite文件路徑 
NSString *docs = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];NSURL *url = [NSURL fileURLWithPath:[docs stringByAppendingPathComponent:@"person.data"]];
// 添加持久化存儲(chǔ)庫，這里使用SQLite作為存儲(chǔ)庫 
NSError *error = nil;
NSPersistentStore *store = [psc addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:url options:nil error:&error];
if (store == nil) { // 直接拋異常  
    [NSException raise:@"添加數(shù)據(jù)庫錯(cuò)誤" format:@"%@", [error localizedDescription]];
}
// 初始化上下文，設(shè)置persistentStoreCoordinator屬性 
NSManagedObjectContext *context = [[NSManagedObjectContext alloc] init];context.persistentStoreCoordinator = psc;
// 用完之后，還是要[context release];
/*持久化存儲(chǔ)庫的類型：NSSQLiteStoreType SQLite數(shù)據(jù)庫 
NSBinaryStoreType 二進(jìn)制平面文件 
NSInMemoryStoreType 內(nèi)存庫，無法永久保存數(shù)據(jù) 
雖然這3種類型的性能從速度上來說都差不多，但從數(shù)據(jù)模型中保留下來的信息卻不一樣
在幾乎所有的情景中，都應(yīng)該采用默認(rèn)設(shè)置，使用SQLite作為持久化存儲(chǔ)庫
*/

// 傳入上下文，創(chuàng)建一個(gè)Person實(shí)體對(duì)象 
NSManagedObject *person = [NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:context];
// 設(shè)置簡單屬性 
[person setValue:@"JN" forKey:@"name"];
[person setValue:[NSNumber numberWithInt:22] forKey:@"age"];
// 傳入上下文，創(chuàng)建一個(gè)Card實(shí)體對(duì)象 
NSManagedObject *card = [NSEntityDescription insertNewObjectForEntityForName:@"Card" inManagedObjectContext:context];
[card setValue:@"447640819" forKey:@"no"];
// 設(shè)置Person和Card之間的關(guān)聯(lián)關(guān)系 
[person setValue:card forKey:@"card"];
 // 利用上下文對(duì)象，將數(shù)據(jù)同步到持久化存儲(chǔ)庫 
NSError *error = nil;BOOL success = [context save:&error];
if (!success) { 
    [NSException raise:@"訪問數(shù)據(jù)庫錯(cuò)誤" format:@"%@", [error localizedDescription]];
}
// 如果是想做更新操作：只要在更改了實(shí)體對(duì)象的屬性后調(diào)用[context save:&error]，就能將更改的數(shù)據(jù)同步到數(shù)據(jù)庫

// 初始化一個(gè)查詢請(qǐng)求 
NSFetchRequest *request = [[NSFetchRequest alloc] init];
// 設(shè)置要查詢的實(shí)體 
NSEntityDescription *desc = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:context];
// 設(shè)置排序（按照age降序） 
NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:NO];
request.sortDescriptors = [NSArray arrayWithObject:sort];
// 設(shè)置條件過濾(name like '%JN-1%') 
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"name like %@", @"*JN-1*"];
request.predicate = predicate;
注意：設(shè)置條件過濾時(shí)，數(shù)據(jù)庫里面的%要用*來代替
// 執(zhí)行請(qǐng)求 
NSError *error = nil;
NSArray *objs = [context executeFetchRequest:request error:&error];
if (error) {
   [NSException raise:@"查詢錯(cuò)誤" format:@"%@", [error localizedDescription]];
}
// 遍歷數(shù)據(jù) 
for (NSManagedObject *obj in objs) {
   NSLog(@"name=%@", [obj valueForKey:@"name"]
}

// 傳入需要?jiǎng)h除的實(shí)體對(duì)象
 [context deleteObject:managedObject];
// 將結(jié)果同步到數(shù)據(jù)庫NSError *error = nil;
 [context save:&error];
if (error) { 
  [NSException raise:@"刪除錯(cuò)誤" format:@"%@",[error localizedDescription]];
}

// 那么生成一個(gè)Person實(shí)體對(duì)象就應(yīng)該這樣寫 
Person *person = [NSEntityDescription insertNewObjectForEntityForName:@"Person" inManagedObjectContext:context];
person.name = @"JN";person.age = [NSNumber numberWithInt:24];
Card *card = [NSEntityDescription insertNewObjectForEntityForName:@”Card" inManagedObjectContext:context];
card.no = @”447640819";
person.card = card;