//.h#define single_interface(class) + (class *)shared##class;//.m// \ 代表下一行也属于宏// ##是分隔符#define single_implementation(class) static class *_instance; + (class *)shared##class {     if (_instance == nil) {         _instance = [[self alloc] init];     }     return _instance; }  + (id)allocWithZone:(NSZone *)zone {     static dispatch_once_t onceToken;     dispatch_once(&onceToken, ^{         _instance = [super allocWithZone:zone];     });     return _instance; }

#import <Foundation/Foundation.h>#import "MSUser.h"#import <sqlite3.h>#import "Singleton.h"@interface MSUserManager : NSObject{     sqlite3 * m_pDb;}single_interface(MSUserManager)//增-(void) addUser:(MSUser *)user;//删-(void) deleteUser:(NSInteger)UserId;//改- (void)updateUser:(MSUser *)user;//查-(NSMutableArray *)allUser;@end

#import "MSUserManager.h"#import <sqlite3.h>@implementation MSUserManager   //单例single_implementation(MSUserManager)//在初始化方法中完成数据库链接工作- (id)init{    self = [super init];        if (self) {                //1. 创建数据库        [self openDB];        //2. 创建数据库表        [self createTable];                    }        return self;}//打开数据库，如不存在，则创建。- (void) openDB{    //生成存放在沙盒中的数据库完整路径    NSString * strDocDir = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];    NSString * strDbName = [strDocDir stringByAppendingPathComponent: @"mySqlite3DB.db"];            //sqlite3 数据库的链接，基于该链接可以进行数据库操作    if (SQLITE_OK == sqlite3_open(strDbName.UTF8String, &m_pDb))    {        NSLog(@"创建/打开数据库成功！");    }    else    {        NSLog(@"创建/打开数据库失败！");    }}//创建数据库表//使用DBMANAGE创建，把生成的代码赋值过来就OK了。//表名：tbl_User//IF NOT EXISTS//IOS 把id设为自增，在添加数据的时候，也要用null站位，不能不写。- (void) createTable{    NSString * strSql = @"CREATE TABLE IF NOT EXISTS tbl_User (Id integer NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,UserName text,UserPass text)";        char * pErrorMsg;    if (SQLITE_OK ==  sqlite3_exec(m_pDb, strSql.UTF8String, NULL, NULL, &pErrorMsg)) {        NSLog(@"创建数据表成功!");    }    else    {        NSLog(@"创建数据表失败!");    }    }- (void) execSql:(NSString *)sql msg:(NSString*)msg{    char * pErrorMsg;    if (SQLITE_OK ==  sqlite3_exec(m_pDb, sql.UTF8String, NULL, NULL, &pErrorMsg))    {        NSLog(@"%@成功!", msg);    }    else    {        NSLog(@"%@失败 - %s!", msg, pErrorMsg);    }}#pragma mark - 成员方法//增-(void) addUser:(MSUser *)user{    NSString * strSql = [NSString stringWithFormat: @"INSERT INTO tbl_User VALUES (null, ‘%@‘, ‘%@‘)",                         user.UserName   , user.UserPass];    [self execSql:strSql msg:@"添加"];    }//删-(void) deleteUser:(NSInteger)UserId{    //和增同理}//改- (void)updateUser:(MSUser *)user{    //和增同理}//查-(NSMutableArray *)allUser{    NSString * strSql = @"SELECT * FROM tbl_User";        NSMutableArray * arrReturn = nil;        //1. 评估准备SQL语法是否正确    sqlite3_stmt * pStmt = NULL;    if (SQLITE_OK == sqlite3_prepare_v2(m_pDb, strSql.UTF8String, -1, &pStmt, NULL))    {        arrReturn = [NSMutableArray array];                //2. 如果能正常查询，调用单步执行方法， 依次取得查询结果        //如果得到一行记录        while (SQLITE_ROW == sqlite3_step(pStmt))        {            //3.获取/显示查询结果            int nId = sqlite3_column_int(pStmt, 0);            const unsigned char * pUserName = sqlite3_column_text(pStmt, 1);            NSString * pUserNameUTF8 = [NSString stringWithUTF8String:(const char *)pUserName];            const unsigned char * pUserPass = sqlite3_column_text(pStmt, 2);            NSString * pUserPassUTF8 = [NSString stringWithUTF8String:(const char *)pUserPass];                        MSUser * pUser = [MSUser UserWithId:nId name:pUserNameUTF8 pass:pUserPassUTF8];            [arrReturn addObject:pUser];        }    }    else    {        NSLog(@"sql语法错误!");    }    //4. 释放句柄    sqlite3_finalize(pStmt);        return arrReturn;}@end

#import <Foundation/Foundation.h>@interface MSUser : NSObject//工厂方法//return User信息+(id) UserWithId:(NSInteger)nId name:(NSString *)strUserName pass:(NSString *)strUserPass;@property (assign , nonatomic) NSInteger Id;@property (strong , nonatomic) NSString * UserName;@property (strong , nonatomic) NSString * UserPass;@end

#import "MSUser.h"@implementation MSUser+(id) UserWithId:(NSInteger)nId name:(NSString *)strUserName pass:(NSString *)strUserPass{    MSUser * pUser = [[MSUser alloc] init];    pUser.Id = nId;    pUser.UserName = strUserName;    pUser.UserPass = strUserPass;    return pUser;}//- (NSString *)description{    return [NSString stringWithFormat:@"< MSUser:%p  Id:%i  UserName:(%@)  UserPass:(%@) >",           self, _Id, _UserName, _UserPass];}@end

#import "MSViewController.h"#import "MSUserManager.h"#import "MSUser.h"@interface MSViewController ()@end@implementation MSViewController- (void)viewDidLoad{    [super viewDidLoad];        m_arrUser = [[MSUserManager sharedMSUserManager] allUser];    NSLog(@"%@", m_arrUser);    }@end