iOS --SQL的增加、删除、查找、修改

iOS对于数据库的操作：增加、删除、查找、修改

首先需要创建一个数据库：本程序的数据库是在火狐浏览器里的插件里写的微量型数据库

火狐找查找SQLite Manager的步骤：

第一步：在工具栏找到附加组件，点击进入

第二步：搜索 SQP，找到并下载，安装完成之后需要重启浏览器

第三步：在工具只乐观找到SQLite Manager，点击打开

SQLite Manager界面如图所示

注：SQLite Manager是微量型的数据库编程软件，所以一次只能执行一句代码！！！

• 创建数据库

--数据库的建立
create table team
(
　-- 创建名字为team的table
　　stu_id integer primary key autoincrement, 
　　stu_name varchar(100), 
　　stu_password varchar(100), 
　　stu_login varchar(100)
 )
--添加信息
 insert into team(stu_name,stu_password,stu_login) values('xiaming','123456','xm')
 insert into team(stu_name,stu_password,stu_login) values('zhangsan','123456',' zs') 
--查询信息
select *from team 
--删除信息
delete from team where stu_id=3

工程目录文件如下：

这里需要导入一个系统自带的文件libsqlite3.0.tbd

步骤如图：

• 实现工程

ViewController.h

#import <UIKit/UIKit.h>
#import <sqlite3.h>
@interface ViewController : UIViewController

@property(strong,nonatomic)UIButton *showbtn;
@property(strong,nonatomic)UIButton *insertbtn;
@property(strong,nonatomic)UIButton *updatebtn;
@property(strong,nonatomic)UIButton *deletebtn;

@end

ViewController.h

#import "ViewController.h"

#define PATH  [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"team.sqlite"]

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // 获取沙盒 Documents文件路径
    NSLog(@"%@",[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject]);
    [self button];
    
}

-(void)button
{
    self.showbtn=[UIButton buttonWithType:UIButtonTypeSystem];
    self.showbtn.frame=CGRectMake(100, 50, 200, 50);
    [self.showbtn setTitle:@"数据库显示" forState:UIControlStateNormal];
    [self.showbtn addTarget:self action:@selector(showSql) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.showbtn];
    
    self.insertbtn=[UIButton buttonWithType:UIButtonTypeSystem];
    self.insertbtn.frame=CGRectMake(100, 100, 200, 50);
    [self.insertbtn setTitle:@"数据库添加" forState:UIControlStateNormal];
    [self.insertbtn addTarget:self action:@selector(insertSql) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.insertbtn];
    
    self.updatebtn=[UIButton buttonWithType:UIButtonTypeSystem];
    self.updatebtn.frame=CGRectMake(100, 150, 200, 50);
    [self.updatebtn setTitle:@"数据库修改" forState:UIControlStateNormal];
    [self.updatebtn addTarget:self action:@selector(updateSql) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.updatebtn];
    
    self.deletebtn=[UIButton buttonWithType:UIButtonTypeSystem];
    self.deletebtn.frame=CGRectMake(100, 200, 200, 50);
    [self.deletebtn setTitle:@"数据库删除" forState:UIControlStateNormal];
    [self.deletebtn addTarget:self action:@selector(deleteSql) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.deletebtn];
}

#pragma mark - 显示数据表中的所有信息
-(void)showSql
{
    NSLog(@"显示数据库信息");
    // 数据库
    sqlite3 *db;
    // 根据指定的数据库文件存储路径打开数据库
    int result=sqlite3_open([PATH UTF8String], &db);
    // 创建执行命令对象
    sqlite3_stmt *stmt;
    // 打开数据库成功
    if (result==SQLITE_OK) {
        NSLog(@"连接成功");
       //  执行预处理命令
        int res=sqlite3_prepare_v2(db, "select *from team", -1, &stmt, nil);
        if (res==SQLITE_OK) {
            // 循环遍历数据表的行信息
            while (sqlite3_step(stmt)==SQLITE_ROW) {
                // 获取数据表中整型列的信息
                int stu_id=sqlite3_column_int(stmt, 0);
                NSLog(@"stu_id is %d",stu_id);
                // 获取数据表中字符型的列的信息
                NSLog(@"%@",[NSString stringWithFormat:@"%s",sqlite3_column_text(stmt, 1)]);
                 NSLog(@"%@",[NSString stringWithFormat:@"%s",sqlite3_column_text(stmt, 2)] );
                NSLog(@"%@",[NSString stringWithFormat:@"%s",sqlite3_column_text(stmt, 3)] ); 
            }
        }
    }
}

#pragma mark -增加信息
-(void)insertSql
{
    sqlite3 *db;
    sqlite3_stmt *stmt;
    sqlite3_open([PATH UTF8String], &db);
    int rst=sqlite3_prepare_v2(db, "insert into team(stu_name,stu_password,stu_login) values(?,?,?)", -1, &stmt, nil);
    sqlite3_bind_text(stmt, 1, "wangwu", -1, nil);
    sqlite3_bind_text(stmt, 2, "123456", -1, nil);
    sqlite3_bind_text(stmt, 3, "ww", -1, nil);
    
    // 判断是否增加成功
    if (rst==SQLITE_OK) {
        if (SQLITE_DONE==sqlite3_step(stmt)) {
            NSLog(@"add ok");
        }else{
            NSLog(@"add fail");
        }
    }
}

#pragma mark - 修改数据库
-(void)updateSql
{
    sqlite3 *db;
    sqlite3_stmt *stmt;
    sqlite3_open([PATH UTF8String], &db);
    // 方法一
    /*
     int res = sqlite3_prepare_v2(db, "update  team set stu_name=(?),stu_password=(?),stu_login=(?) where stu_id=2" , -1, &stmt, nil);
     sqlite3_bind_text(stmt, 1, "xiaoming", -1, nil);
     sqlite3_bind_text(stmt, 2, "123456", -1, nil);
     sqlite3_bind_text(stmt, 3, "xm", -1, nil);
     */
    // 方法二
    int rst=sqlite3_prepare_v2(db, "update team setstu_name='zl',stu_password='zl123',stu_login='zhangsan' where stu_id=4", -1, &stmt, nil);
   

    // 判断是否修改成功
    if (rst==SQLITE_OK) {
        if (SQLITE_DONE == sqlite3_step(stmt)) {
            NSLog(@" update ok");
        }else{
            NSLog(@"update fail");
        }
    }
}

-(void)deleteSql
{
    sqlite3 *db;
    sqlite3_stmt *stmt;
    sqlite3_open([PATH UTF8String], &db);
    int rst=sqlite3_prepare_v2(db, "delete from team where stu_id=9", -1, &stmt, nil);
    
    // 判断是否删除成功
    if (rst==SQLITE_OK) {
        if (SQLITE_DONE==sqlite3_step(stmt)) {
                NSLog(@" delete ok");
            }else{
                NSLog(@"delete fail");
        }
    }
}

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

@end