iOS中 FMDB第三方SQLite数据库 UI_20

1.什么是FMDB?

FMDB是iOS平台下SQLite数据库,只不过它是OC方式封装了C语言的SQLite语句,使用起来更加面向对象

2.FMDB的优点:1.使用起来更加面向对象; 2.对比苹果自带的 Core Data 数据管理工具更加的轻量级,更加的灵活,而且FMDB支持跨平台; 3.提供多线程下的数据安全保护机制,有效地防止数据混乱

3.FMDM中重要的类:

FMDBDataBase: 它代表一个数据库对象,(我们需要创建数据库对象时就使用这个类)

FMDBDataBaseQueue: 它提供多线程下执行查找删除,或者更新的数据安全保护

FMResultSet: 用来存储sql语句执行结果的集(我们执行完sql语句后得到的结果都在这个类的对象中)

ViewController.m

#import "FMDB.h"
#import "Person.h"
#import "DetailViewController.h"
@interface ViewController ()
@property(nonatomic,retain)FMDatabase *db;
@property(nonatomic,retain)NSMutableArray *dataArray;//存储查询到的所有Person对象
@end

@implementation ViewController
- (void)dealloc
{
    self.db = nil;
    self.dataArray = nil;
    [super dealloc];
}
- (NSMutableArray *)dataArray{
    if (_dataArray == nil) {
        self.dataArray = [NSMutableArray arrayWithCapacity:0];
    }

    return [[_dataArray retain]autorelease];
}

调用:(介绍FMDB)

- (void)viewDidLoad {
    [super viewDidLoad];
    //获取Documents文件夹路径
    NSString *urlString = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject];
    //在Documents文件夹里创建数据库文件 db.sqlite
    NSString *dbPath = [urlString stringByAppendingPathComponent:@"db.sqlite"];
    //创建数据库对象
    //参数:数据库的路径
    //执行结束后并没有帮我们生成数据库文件,只是帮我们创建了数据库对象
    FMDatabase *db = [FMDatabase databaseWithPath:dbPath];
    NSLog(@"%@",NSHomeDirectory());
    //代开数据库
    //open操作才帮我们真正的创建数据库文件,且如果已经打开,直接返回YES,此时可以直接使用,如果打开失败会打印报错信息
   BOOL isOpen = [db open];
    if (isOpen) {
        NSLog(@"打开成功");
        //创建表格
        //executeUpdate 除了查询之外,其他数据创建表格,插入数据、删除数据都是用这个方法
        //blob 二进制流 相当于oc的NSData
     BOOL isCreat =   [db executeUpdate:@"create table if not exists Person(id integer primary key autoincrement,name text,gender text,age integer,photo blob)"];
        NSLog(@"%@",isCreat ? @"建表成功":@"建表失败");

    }else{
        NSLog(@"打开失败");
    }
    //给属性赋值
    self.db = db;
    NSLog(@"%@",NSHomeDirectory());
}

插入:

- (IBAction)insert:(UIButton *)sender {
    Person *p = [[Person alloc]initWithName:@"郭美美" gender:@"女" age:20 photo:[UIImage imageNamed:@"3.gif"]];

    //将图片转化成NSData对象
    NSData *data = UIImagePNGRepresentation(p.photo);

    //@(p.age)参数必须是对象类型的才能使用
    //插入操作
 BOOL isInsert =   [self.db executeUpdate:@"insert into Person(name,gender,age,photo)values(?,?,?,?)",p.name,p.gender,@(p.age),data];
    NSLog(@"%@",isInsert ? @"插入成功":@"插入失败");
}

删除:

- (IBAction)delete:(UIButton *)sender {
    //根据条件删除
BOOL result =    [self.db executeUpdate:@"delete from Person where id = ?",@3];
    NSLog(@"%@",result ? @"删除成功":@"删除失败");
    //删除全部表格内容
//    BOOL isResult1 = [self.db executeUpdate:@"delete from Person"];
    //删除表格
//    BOOL isResult2 = [self.db executeUpdate:@"drop table Person"];
}

更新:

- (IBAction)update:(UIButton *)sender {
    BOOL isUpdate = [self.db executeUpdate:@"update Person set gender = ? where id = ?",@"男",@4];
    NSLog(@"%@",isUpdate ? @"更新成功":@"更新失败");
}

查询:

- (IBAction)select:(UIButton *)sender {
    //查询全部
    FMResultSet *set = [self.db executeQuery:@"select * from Person"];

    //按条件查询
//    FMResultSet *set = [self.db executeQuery:@"select *from Person where name = ?",@"郭美美"];

    self.dataArray = [NSMutableArray arrayWithCapacity:0];
    //循环取出表中的数据
    //[set next] 判断写一行是否有数据
    while ([set next]) {
        //取出每一个字段对应的数据
        NSInteger ID = [set intForColumn:@"id"];//取出id字段下的数据
        NSString *name = [set stringForColumn:@"name"];//取出name字段下的数据
        NSString *gender = [set stringForColumn:@"gender"];//取出gender字段下的数据
        NSInteger age = [set intForColumn:@"age"];//取出age字段下的数据
        NSData *data = [set dataForColumn:@"photo"];//取出photo字段下的数据
        //创建model类
        //将二进制流转成图片
        UIImage *image = [UIImage imageWithData:data];

        Person *p = [[Person alloc]initWithName:name gender:gender age:age photo: image];
        p.ID = ID;

        [self.dataArray addObject:p];
        [p release];

    }
}

为了展现效果,我们push到下个页面查看效果:

需要准备一个自定义cell、UIViewController界面和model类

传值使用:

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    //获取segue起始端的视图控制器对象
    ViewController *rootVC  = [segue sourceViewController];

    //通过segue完成跳转的时候会触发这个方法,在跳转之前触发,一般用来传值
    //获取push过去后的视图控制器对象
    DetailViewController *detailVC = [segue destinationViewController];
    //属性传值
    detailVC.dataSource = rootVC.dataArray;

}

准备一个UIViewController:

DetailViewController.h
@interface DetailViewController : UITableViewController
@property(nonatomic,retain)NSMutableArray *dataSource;//属性传值使用
@end

DetailViewController.m
#import "DetailViewController.h"
#import "Person.h"
#import "PersonCell.h"
#define kPersonCell @"personcell"
@interface DetailViewController ()
@end
@implementation DetailViewController
- (void)dealloc
{
    self.dataSource = nil;
    [super dealloc];
}
- (void)viewDidLoad {
    [super viewDidLoad];
}

#pragma mark - Table view data source

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    // Return the number of sections.
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    // Return the number of rows in the section.
    return self.dataSource.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
     PersonCell *cell = [tableView dequeueReusableCellWithIdentifier:kPersonCell forIndexPath:indexPath];
    //建立model类
    Person *person = self.dataSource[indexPath.row];
    //调用cell赋值的方法
    [cell assginValues:person];

    return cell;
}

准备一个自定义cell:通过storyBoard实现;

布局如下:

iOS中 FMDB第三方SQLite数据库 UI_20

PersonCell.h
#import <UIKit/UIKit.h>
@class Person;
@interface PersonCell : UITableViewCell
@property (retain, nonatomic) IBOutlet UILabel *nameLabel;
@property (retain, nonatomic) IBOutlet UILabel *genderLabel;
@property (retain, nonatomic) IBOutlet UILabel *ageLabel;
@property (retain, nonatomic) IBOutlet UIImageView *photoView;
@property (retain, nonatomic) IBOutlet UILabel *IDLabel;
//写一个赋值方式
- (void)assginValues : (Person *)person;
@end

//=================================================
PersonCell.m
#import "PersonCell.h"
#import "Person.h"
@implementation PersonCell

- (void)awakeFromNib {
    // Initialization code
}

//写一个赋值方式
- (void)assginValues : (Person *)person{
    self.nameLabel.text = person.name;
    self.genderLabel.text = person.gender;
    self.ageLabel.text = [NSString stringWithFormat:@"%ld",person.age];
    self.photoView.image = person.photo;
    self.IDLabel.text = [NSString stringWithFormat:@"%ld",person.ID];
}

- (void)dealloc {
    [_nameLabel release];
    [_genderLabel release];
    [_ageLabel release];
    [_photoView release];
    [_IDLabel release];
    [super dealloc];
}
@end

准备一个model类:

Person.h
#import <Foundation/Foundation.h>
@class UIImage;
@interface Person : NSObject
@property(nonatomic,copy)NSString *name,*gender;
@property(nonatomic)NSInteger age,ID;//基本数据类型可以省略内存修饰符assign,因为默认使用的就是assign
@property(nonatomic,retain)UIImage *photo;
//自定义初始化方法
- (id)initWithName : (NSString *)name  gender : (NSString *)gender age : (NSInteger)age photo : (UIImage *)photo;
@end
//=============================
Person.m
#import "Person.h"
#import <UIKit/UIKit.h>
@implementation Person
- (void)dealloc
{
    self.name = nil;
    self.gender = nil;
    self.photo = nil;
    [super dealloc];
}

//自定义初始化方法
- (id)initWithName : (NSString *)name  gender : (NSString *)gender age : (NSInteger)age photo : (UIImage *)photo{
    if (self = [super init]) {
        self.name = name;
        self.gender = gender;
        self.age = age;
        self.photo = photo;
    }
        return self;
 }
- (NSString *)description
{
    return [NSString stringWithFormat:@"%@ %@ %ld %@", self.name,self.gender,self.age,self.photo];
}
@end

大概效果不能展示全部(仅供参考):

iOS中 FMDB第三方SQLite数据库 UI_20

==============================

第三方FMDB下载:http://pan.baidu.com/s/1ntMo3ZN

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