Oc FMDB+SQL语句

FMDB使用介绍
iOS中原生的SQLite API在使用上相当不友好，在使用时，非常不便。于是，就出现了一系列将SQLite API进行封装的库FMDB (https://github.com/ccgus/fmdb) 是一款简洁、易用的封装库，这一篇文章简单介绍下FMDB的使用。
一、简单说明
1.什么是FMDB
FMDB是iOS平台的SQLite数据库框架
FMDB以OC的方式封装了SQLite的C语言API

2.FMDB的优点
使用起来更加面向对象，省去了很多麻烦、冗余的c语言代码
对比苹果自带的Core Data框架，更加轻量级和灵活
提供了多线程安全的数据库操作方法，有效地防止数据混乱

FMDB PK Sqlite
优点:
对多线程的并发操作进行处理，所以是线程安全的；
以OC的方式封装了SQLite的C语言API，使用起来更加的方便；
FMDB是轻量级的框架，使用灵活。

缺点:
因为它是OC的语言封装的，只能在ios开发的时候使用，所以在实现跨平台操作的时候存在局限性。

3.FMDB的github地址
https://github.com/ccgus/fmdb

二、核心类
FMDB有三个主要的类
（1）FMDatabase
一个FMDatabase对象就代表一个单独的SQLite数据库
用来执行SQL语句

（2）FMResultSet
使用FMDatabase执行查询后的结果集

（3）FMDatabaseQueue
用于在多线程中执行多个查询或更新，它是线程安全的

1.AppDelegate.m 中的代码

#import "AppDelegate.h"#import "ViewController.h"//主控制器@interface AppDelegate ()@end@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    //初始化    ViewController *vc = [[ViewController alloc]init];    //导航控制器    UINavigationController *nvc = [[UINavigationController alloc]initWithRootViewController:vc];    //添加图    self.window.rootViewController = nvc;    return YES;}

2.导入第三方数据库 FMDB 框架包
下载地址:https://github.com/ccgus/fmdb
* 注意:要导入 libsqlite3.tbd 包 (详情请看上面图3)*

3.在 Other 模块中添加业务处理层处理 SQLite 语句
注意:如果现在拷贝到项目会报错–>原因是其他 MVC 模块中的类没有实现

控制器1 .h:

#import <Foundation/Foundation.h>#import "Model.h"#import "FMDatabase.h"@interface LoadData : NSObject//单列类+(instancetype)sharlLoadData;//添加元素-(void)AddsharlLoadData:(Model *)model;//查询-(NSMutableArray *)Marr;//删除元素-(void)deleteharlLoadData:(Model *)model;//修改元素-(void)UPsharlLoadData:(Model *)model;@end

控制器1 .M:

#import "LoadData.h"static LoadData *ld =nil;static FMDatabase *fate;@implementation LoadData//单列类+(instancetype)sharlLoadData{    //静态    staticdispatch_once_t oneet;    //初始化    dispatch_once(&oneet, ^{        ld = [[LoadData alloc]init];        //定义初始化        [ld initA];    });    //返回值    return ld;}//初始化+(instancetype)allocWithZone:(struct_NSZone *)zone{    if (!ld) {        //初始化        ld = [super allocWithZone:zone];    }    return ld;}//浅复制-(id)copy{    return self;}//深复制-(id)mutableCopy{    return self;}//初始化数据库-(void)initA{    //创建沙盒    NSString *Ste = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES)objectAtIndex:0];    //定义文件名    NSString *path = [Ste stringByAppendingPathComponent:@"HousingInfo.sqlite"];    //初始化    fate = [[FMDatabase alloc]initWithPath:path];    //判断    if ([fate open]) {        //初始化        [fate executeUpdate:@"create table class (ID integer primary key, fieldMail text, fieldAddress text , fieldConsignee text , fieldPhone text , fieldNote text)"];        [fate close];        NSLog(@"成功");    }else{        NSLog(@"失败");    }}//添加元素-(void)AddsharlLoadData:(Model *)model{    //开始    [fate open];    //初始化    NSString *str = [NSString stringWithFormat:@"insert into class values (null , '%@','%@','%@','%@','%@')",model.fieldMail,model.fieldAddress,model.fieldConsignee,model.fieldPhone,model.fieldNote];    //BOOL值接受    BOOL ii = [fate executeUpdate:str];    //判断    if (ii) {        NSLog(@"成功");    }else{        NSLog(@"失败");    }    //关闭    [fate close];}//查询-(NSMutableArray *)Marr{    //初始化    NSMutableArray *marr = [NSMutableArray new];    //开始    [fateopen];    //初始化    FMResultSet *Set = [[FMResultSet alloc]init];    //使用set接受    Set = [fate executeQuery:@"select * from class"];    //判断   while ([Setnext]) {        //初始化        Model *mm = [Modelnew];        //链接        mm.fieldMail = [Set stringForColumn:@"fieldMail"];        mm.fieldAddress = [Set stringForColumn:@"fieldAddress"];        mm.fieldConsignee = [Set stringForColumn:@"fieldConsignee"];        mm.fieldPhone = [Set stringForColumn:@"fieldPhone"];        mm.fieldNote = [Set stringForColumn:@"fieldNote"];        mm.ID = [Set intForColumn:@"ID"];        //添加到数组        [marr addObject:mm];    }    //关闭    [fate close];    //返回值    return marr;}//删除元素-(void)deleteharlLoadData:(Model *)model{    //开始    [fate open];    //初始化    NSString *str = [NSString stringWithFormat:@"delete from class where ID = '%ld' ",model.ID];    //BOOL值接受    BOOL ii = [fate executeUpdate:str];    //判断    if (ii) {        NSLog(@"成功");    }else{        NSLog(@"失败");    }    //关闭    [fate close];}//修改元素-(void)UPsharlLoadData:(Model *)model{    //开始    [fate open];    //初始化    NSString *str = [NSString stringWithFormat:@"update class set fieldMail = '%@',fieldAddress = '%@',fieldConsignee = '%@',fieldPhone = '%@',fieldNote = '%@' where ID = '%ld'",model.fieldMail,model.fieldAddress,model.fieldConsignee,model.fieldPhone,model.fieldNote,model.ID]    //BOOL值接受    BOOL ii = [fate executeUpdate:str];    //判断    if (ii) {        NSLog(@"成功");    }else{        NSLog(@"失败");    }    //关闭    [fate close];}@end

4.MVC–>C模块
控制器1 -主控制器 .m:

#import "ViewController.h"#import "LoadData.h"//业务处理 SQLite#import "Model.h" //保存数据#import "MyTableViewCell.h"//主控制器 cell#import "UpViewController.h"//修改信息控制器#import "AddViewController.h"//添加信息控制器@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>{    UITableView *tabele;    NSMutableArray *marr;}@end@implementation ViewController//将要显示-(void)viewWillAppear:(BOOL)animated{    //查询    marr = [[LoadData sharlLoadData]Marr];    //刷新    [tabele reloadData ];}- (void)viewDidLoad {    [super viewDidLoad];    //定义标题    self.title =@"信息查询系统";    //初始化    tabele = [[UITableView alloc]initWithFrame:self.view.framestyle:UITableViewStylePlain];    //添加协议    tabele.delegate =self;    tabele.dataSource =self;    //添加到试图上    [self.view addSubview:tabele];    //定义按钮    UIBarButtonItem *right = [[UIBarButtonItem alloc]initWithTitle:@"添加"style:UIBarButtonItemStylePlain target:selfaction:@selector(click)];  //添加到导航调试    self.navigationItem.rightBarButtonItem = right;}-(void)click{    //初始化    AddViewController *add = [AddViewController new];    //跳转    [self.navigationController pushViewController:addanimated:YES];}//行数-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    returnmarr.count;}-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    static NSString *cellId = @"CELLID";    //初始化    MyTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellId];    //复用池    if (!cell) {        //初始化‘        cell = [[MyTableViewCell alloc]initWithStyle:UITableViewCellStyleSubtitlereuseIdentifier:cellId];    }    //初始化    Model *mm =marr[indexPath.row];    //添加到表格上    cell.fieldMail.text = mm.fieldMail;    cell.fieldAddress.text = mm.fieldAddress;    cell.fieldConsignee.text = mm.fieldConsignee;    cell.fieldPhone.text = mm.fieldPhone;    cell.fieldNote.text = mm.fieldNote;    //返回值    return cell;}//删除-(void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath{    //添加    Model *mm  =marr[ indexPath.row];    //删除    [[LoadData sharlLoadData]deleteharlLoadData:mm];    [marr removeObjectAtIndex:indexPath.row];    //刷新    [tabele reloadData];}//跳转-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{    //初始化    UpViewController *up = [UpViewController new];    //添加    up.mm = marr[indexPath.row];    //修改    [[LoadData sharlLoadData]UPsharlLoadData:up.mm];    //跳转    [self.navigationController pushViewController:up animated:YES];}@end

控制器2–添加信息控制器 .m:

#import "AddViewController.h"#import "Model.h"#import "LoadData.h"@interface AddViewController ()//邮件@property (strong,nonatomic)IBOutletUITextField *fieldMail;//收货地址@property (strong,nonatomic)IBOutletUITextField *fieldAddress;//收货人@property (strong,nonatomic)IBOutletUITextField *fieldConsignee;//电话@property (strong,nonatomic)IBOutletUITextField *fieldPhone;//备注@property (strong,nonatomic)IBOutletUITextField *fieldNote;//点击添加信息- (IBAction)sss:(id)sender;@end@implementation AddViewController- (void)viewDidLoad {    [superviewDidLoad];}- (IBAction)sss:(id)sender {    //初始化    Model *mm = [Model new];    //链接    mm.fieldMail =self.fieldMail.text;    mm.fieldAddress =self.fieldAddress.text;    mm.fieldConsignee =self.fieldConsignee.text;    mm.fieldPhone =self.fieldPhone.text;    mm.fieldNote =self.fieldNote.text;    //添加到数据库    [[LoadData sharlLoadData]AddsharlLoadData:mm];    //跳转    [self.navigationController popViewControllerAnimated:YES];}@end

控制器3–修改信息控制器 .h:

#import <UIKit/UIKit.h>@class Model;@interface UpViewController : UIViewController//定义属性@property (nonatomic ,strong)Model *mm;@end

控制器3–修改信息控制器 .m:

#import "UpViewController.h"#import "LoadData.h"#import "Model.h"@interface UpViewController ()//邮件@property (strong,nonatomic)IBOutletUITextField *fieldMail;//收货地址@property (strong,nonatomic)IBOutletUITextField *fieldAddress;//收货人@property (strong,nonatomic)IBOutletUITextField *fieldConsignee;//电话@property (strong,nonatomic)IBOutletUITextField *fieldPhone;//备注@property (strong,nonatomic)IBOutletUITextField *fieldNote;//点击修改信息- (IBAction)ssss:(id)sender;@end@implementation UpViewController- (void)viewDidLoad {    [superviewDidLoad];    //将数据添加到修改页面    self.fieldMail.text =self.mm.fieldMail;    self.fieldAddress.text =self.mm.fieldAddress;    self.fieldConsignee.text =self.mm.fieldConsignee;    self.fieldPhone.text =self.mm.fieldPhone;    self.fieldNote.text =self.mm.fieldNote;}- (IBAction)ssss:(id)sender {    //初始化    Model *mm = self.mm;    //链接    mm.fieldMail = self.fieldMail.text;    mm.fieldAddress = self.fieldAddress.text;    mm.fieldConsignee = self.fieldConsignee.text;    mm.fieldPhone = self.fieldPhone.text;    mm.fieldNote = self.fieldNote.text;    //添加    [[LoadData sharlLoadData]UPsharlLoadData:mm];    //跳转    [self.navigationController popViewControllerAnimated:YES];}@end

5.MVC–>V模块

控制器1– .h:

#import <UIKit/UIKit.h>@interface MyTableViewCell : UITableViewCell//邮件@property (nonatomic ,strong)UILabel *fieldMail;//收货地址@property (nonatomic ,strong)UILabel *fieldAddress;//收货人@property (nonatomic ,strong)UILabel *fieldConsignee;//电话@property (nonatomic ,strong)UILabel *fieldPhone;//备注@property (nonatomic ,strong)UILabel *fieldNote;@end

控制器1– .m:

#import "MyTableViewCell.h"@implementation MyTableViewCell//重写父类方法-(instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{    //判断    if ([superinitWithStyle:stylereuseIdentifier:reuseIdentifier]) {        //添加到        [self.contentView addSubview:self.fieldMail];        [self.contentView addSubview:self.fieldAddress];        [self.contentView addSubview:self.fieldConsignee];        [self.contentView addSubview:self.fieldPhone];        [self.contentView addSubview:self.fieldNote];    }    //返回值    returnself;}//懒加载-//邮件-(UILabel *)fieldMail{    //判断    if (!_fieldMail) {        //初始化        _fieldMail = [[UILabel alloc]initWithFrame:CGRectMake(5,5,80,44)];    }    //返回值    return_fieldMail;}//懒加载-//收货地址-(UILabel *)fieldAddress{    //判断    if (!_fieldAddress) {        //初始化        _fieldAddress = [[UILabel alloc]initWithFrame:CGRectMake(80,5,80,44)];    }    //返回值    return_fieldAddress;}//懒加载=//收货人-(UILabel *)fieldConsignee{    //判断    if (!_fieldConsignee) {        //初始化        _fieldConsignee = [[UILabel alloc]initWithFrame:CGRectMake(155,5,80,44)];    }    //返回值    return_fieldConsignee;}//懒加载--//电话-(UILabel *)fieldPhone{    //判断    if (!_fieldPhone) {        //初始化        _fieldPhone = [[UILabel alloc]initWithFrame:CGRectMake(220,5,80,44)];    }    //返回值    return _fieldPhone;}//懒加载-(UILabel *)fieldNote{    //判断    if (!_fieldNote) {        //初始化        _fieldNote = [[UILabel alloc]initWithFrame:CGRectMake(305,5,80,44)];    }    //返回值    return _fieldNote;}- (void)awakeFromNib {    [super awakeFromNib];}- (void)setSelected:(BOOL)selected animated:(BOOL)animated {    [super setSelected:selected animated:animated];}@end

6.MVC–>M模块

控制器1– .h:

#import <Foundation/Foundation.h>@interface Model : NSObject//定义属性//邮箱@property (nonatomic ,copy)NSString *fieldMail;//收货地址@property (nonatomic ,copy)NSString *fieldAddress;//收货人@property (nonatomic ,copy)NSString *fieldConsignee;//电话@property (nonatomic ,copy)NSString *fieldPhone;//备注@property (nonatomic ,copy)NSString *fieldNote;//@property (nonatomic ,assign)NSInteger ID;@end

控制器1– .m:

#import "Model.h"@implementation Model@end