sqlite3简单操作

女爷i 2022-08-01 13:41 210阅读 0赞

//
    //  ViewController.m
    //  SqlLite
    //
    //  Created by 麦子 on 15/6/25.
    //  Copyright (c) 2015年 麦子. All rights reserved.
    //
    
    #import "ViewController.h"
    #import <sqlite3.h> // 系统目录下，
    
    @interface ViewController ()
    
    @end
    
    @implementation ViewController{
    
       sqlite3_stmt *stmt;
    }
    
    - (void)viewDidLoad {
        [super viewDidLoad];
         self.title = @"sqlLite学习";
        self.view.backgroundColor = [UIColor whiteColor];
        [self SqlLiteHandle];
    }
    
    /****
        数据库操作  和 java的一样，同时也有预处理，只是这些操作都是用C函数来进行处理
     
        都在sqlite3这个包里面。
     
     */
    - (void)SqlLiteHandle{
        // 打开数据库
        NSString *path = NSHomeDirectory();
        path = [path stringByAppendingPathComponent:@"mydb.sqlite"];//不存在就创建，然后打开
        NSLog(@"%@",path); // 每次创建都不一样的路径
        sqlite3 *db;
        int result = sqlite3_open([path UTF8String], &db);
        if (result != SQLITE_OK) {
            NSLog(@"数据库打开失败");
        }
        // 操作数据库
        [self createTable:db];
        
        // 删除
        [self tableDel:db];
        
        // 添加
        [self tableAdd:db];
        
        // 修改
        [self tableUpdate:db];
        
        // 查找
        [self tableFind:db];
        
        // 关闭数据库
        sqlite3_finalize(stmt);
        sqlite3_close(db);
    
    }
    
    // 创建表
    - (void)createTable:(sqlite3 *)sqliteDb{
       NSString *sql = @"create table if not exists student(name text,sex text,age integer)";
        char *err; // 出错对象
        int result = sqlite3_exec(sqliteDb,[sql UTF8String],NULL,NULL,&err);
        if (result == SQLITE_OK) {
            NSLog(@"创建表成功....");
            
        }
    }
    
    
    // 增加
    - (void)tableAdd:(sqlite3 *)sqliteDb{
        NSString *sql = @"insert into student (name,sex,age) values ('小强','男',25)";
        char *err; // 出错对象
        int result = sqlite3_exec(sqliteDb,[sql UTF8String],NULL,NULL,&err);
        if (result == SQLITE_OK) {
            NSLog(@"添加成功....");
        }
    
    }
    
    
    // 删除
    - (void)tableDel:(sqlite3 *)sqliteDb{
        NSString *sql = @"delete from student";
        char *err; // 出错对象
        int result = sqlite3_exec(sqliteDb,[sql UTF8String],NULL,NULL,&err);
        if (result == SQLITE_OK) {
            NSLog(@"删除成功....");
        }
    }
    
    
    //修改
    - (void)tableUpdate:(sqlite3 *)sqliteDb{
        NSString *sql = @"update student set name = '麦子' ";
        char *err; // 出错对象
        int result = sqlite3_exec(sqliteDb,[sql UTF8String],NULL,NULL,&err);
        if (result == SQLITE_OK) {
            NSLog(@"修改成功....");
        }
    }
    
    // 查找
    - (NSArray *)tableFind:(sqlite3 *)sqliteDb{
        NSString *sql = @"select * from student";
        
        int result = sqlite3_prepare_v2(sqliteDb, [sql UTF8String], -1, &stmt, NULL);
        if (result == SQLITE_OK) {
            NSLog(@"查询成功....");
            // 循环  重这个结果集里面获取数据，也是以二维数组的形式来获取
            while (sqlite3_step(stmt) == SQLITE_ROW) {
                char *name = (char *)sqlite3_column_text(stmt, 0);
                char *sex = (char *)sqlite3_column_text(stmt, 1);
                int  age = sqlite3_column_int(stmt, 2);
                NSString *strName = [NSString stringWithUTF8String:name];
                NSString *strSex = [NSString stringWithUTF8String:sex];
                NSLog(@"name=%@-->sex=%@-->age=%d",strName,strSex,age);
                
            }
        }
        return nil;
    }
    
    
    
    - (void)didReceiveMemoryWarning {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }
    
    @end