FMDB的简单实用

浏览数：21 / 时间：2015年06月12日

一.FMDB 的框架引入点击此处去GitHub下载

二.FMDB 的优缺点

　　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。

三.FMDB 中三个基础类：

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；

四.用一个实际列子学习FMDB的简单使用，包括数据库的建立、表的建立、数据的插入、数据的查询，其中数据插入，删除、更改、建表操作方式相同。

　　1..h文件的内容

//
//  ViewController.h
//  FMDB
//
//  Created by linan on 15/3/30.
//  Copyright (c) 2015年 ln. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
@property (weak, nonatomic) IBOutlet UITextField *userName;
@property (weak, nonatomic) IBOutlet UITextField *passWord;

- (IBAction)sureButton:(id)sender;
- (IBAction)registButton:(id)sender;

@end

2..m文件

//
//  ViewController.m
//  FMDB
//
//  Created by linan on 15/3/30.
//  Copyright (c) 2015年 ln. All rights reserved.
//

#import "ViewController.h"
#import "FMDB.h"
@interface ViewController ()
@property(nonatomic,strong)FMDatabase *db;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    NSString *path = [NSHomeDirectory() stringByAppendingString:@"/Documents/"];
    NSString *fmdbPath = [path stringByAppendingString:@"student.sqlite"];
    NSLog(@"path = %@",path);
    self.db = [FMDatabase databaseWithPath:fmdbPath];
    if (![self.db open]) {
        NSLog(@"数据库没有打开");
    }else{
     NSLog(@"数据库已经打开");
        
        //creat table
      BOOL result =  [self.db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_student (id integer PRIMARY KEY AUTOINCREMENT ,name text NOT NULL ,age integer NOT NULL,password text NOT NULL);"];
        if (result) {
            NSLog(@"creat student is success!");
            
            //successfully create and insert date
//            [self insertDate];
        }else{
            NSLog(@"creat student is fail!");
            }
        
    }
   
}
-(void)insertDate{
    for (int i = 0; i < 20; i++) {
        NSString *student_name = [NSString stringWithFormat:@"fool-%d",arc4random()%40];
        NSString *student_passWord = [NSString stringWithFormat:@"123456"];
        int student_age = arc4random()%100;
        
        //未知类型用占位符表示
        [self.db executeUpdate:@"INSERT INTO t_student (name,password,age) VALUES(?,?,?);",student_name,student_passWord,@(student_age)];
    }

}
- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

    //search date from sqlite
- (IBAction)sureButton:(id)sender {
    //execute result
    FMResultSet *result = [self.db executeQuery:@"SELECT *FROM t_student"];
    
    while ([result next]) {
        NSString *name = [result stringForColumn:@"name"];
        NSString *password = [result stringForColumn:@"password"];
        if ([self.userName.text isEqualToString:name]&&[self.passWord.text isEqualToString:password]) {
            [self showAlert:@"登陆成功"];
            break;
        }else{
//
        }
       
    }
    
}

- (IBAction)registButton:(id)sender {
    NSString *student_name = @"zhuce";
    int age = 20;
    NSString *student_passWord = @"123456";
    if ([self.db open]) {
        [self.db executeUpdate:@"INSERT INTO t_student (name,password,age) VALUES (?,?,?);",student_name,student_passWord,@(age)];

    }
    }
-(void)showAlert:(NSString*)message{
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"提示:" message:message delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
    [alert show];
}
@end