IOS-SQLite3的封装

IWStudent.h

//
//  IWStudent.h
//  02-SQLite的封装
//
//  Created by apple on 14-5-22.
//  Copyright (c) 2014年 itcast. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface IWStudent : NSObject
@property (nonatomic, assign) int ID;
@property (nonatomic, copy) NSString *name;
@property (nonatomic, assign) int age;
@end



//
//  IWStudent.m
//  02-SQLite的封装
//
//  Created by apple on 14-5-22.
//  Copyright (c) 2014年 itcast. All rights reserved.
//

#import "IWStudent.h"

@implementation IWStudent

@end

IWStudentTool.h

//
//  IWStudentTool.h
//  02-SQLite的封装
//
//  Created by apple on 14-5-22.
//  Copyright (c) 2014年 itcast. All rights reserved.
//  学生数据的CRUD（增删改查）

#import <Foundation/Foundation.h>
@class IWStudent;

@interface IWStudentTool : NSObject

/**
 *  添加学生
 *
 *  @param student 需要添加的学生
 */
+ (BOOL)addStudent:(IWStudent *)student;

/**
 *  获得所有的学生
 *
 *  @return 数组中装着都是IWStudent模型
 */
+ (NSArray *)students;

/**
 *  根据搜索条件获得对应的学生
 *
 *  @param condition 搜索条件
 */
+ (NSArray *)studentsWithCondition:(NSString *)condition;

@end



//
//  IWStudentTool.m
//  02-SQLite的封装
//
//  Created by apple on 14-5-22.
//  Copyright (c) 2014年 itcast. All rights reserved.
//

#import "IWStudentTool.h"
#import "IWStudent.h"
#import <sqlite3.h>

@implementation IWStudentTool

// static的作用：能保证_db这个变量只被IWStudentTool.m直接访问
static sqlite3 *_db;

+ (void)initialize
{
    // 0.获得沙盒中的数据库文件名
    NSString *filename = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"student.sqlite"];
    
    // 1.创建(打开)数据库（如果数据库文件不存在，会自动创建）
    int result = sqlite3_open(filename.UTF8String, &_db);
    if (result == SQLITE_OK) {
        NSLog(@"成功打开数据库");
        
        // 2.创表
        const char *sql = "create table if not exists t_student (id integer primary key autoincrement, name text, age integer);";
        char *errorMesg = NULL;
        int result = sqlite3_exec(_db, sql, NULL, NULL, &errorMesg);
        if (result == SQLITE_OK) {
            NSLog(@"成功创建t_student表");
        } else {
            NSLog(@"创建t_student表失败:%s", errorMesg);
        }
    } else {
        NSLog(@"打开数据库失败");
    }
}

+ (BOOL)addStudent:(IWStudent *)student
{
    NSString *sql = [NSString stringWithFormat:@"insert into t_student (name, age) values('%@', %d);", student.name, student.age];

    char *errorMesg = NULL;
    int result = sqlite3_exec(_db, sql.UTF8String, NULL, NULL, &errorMesg);
    
    return result == SQLITE_OK;
}

+ (NSArray *)students
{
    // 0.定义数组
    NSMutableArray *students = nil;
    
    // 1.定义sql语句
    const char *sql = "select id, name, age from t_student;";
    
    // 2.定义一个stmt存放结果集
    sqlite3_stmt *stmt = NULL;
    
    // 3.检测SQL语句的合法性
    int result = sqlite3_prepare_v2(_db, sql, -1, &stmt, NULL);
    if (result == SQLITE_OK) {
        NSLog(@"查询语句是合法的");
        students = [NSMutableArray array];
        
        // 4.执行SQL语句，从结果集中取出数据
        while (sqlite3_step(stmt) == SQLITE_ROW) { // 真的查询到一行数据
            // 获得这行对应的数据
            
            IWStudent *student = [[IWStudent alloc] init];
            
            // 获得第0列的id
            student.ID = sqlite3_column_int(stmt, 0);
            
            // 获得第1列的name
            const unsigned char *sname = sqlite3_column_text(stmt, 1);
            student.name = [NSString stringWithUTF8String:(const char *)sname];
            
            // 获得第2列的age
            student.age = sqlite3_column_int(stmt, 2);
            
            // 添加到数组
            [students addObject:student];
        }
    } else {
        NSLog(@"查询语句非合法");
    }
    
    return students;
}

+ (NSArray *)studentsWithCondition:(NSString *)condition
{
    // 0.定义数组
    NSMutableArray *students = nil;
    
    // 1.定义sql语句
    const char *sql = "select id, name, age from t_student where name like ?;";
    
    // 2.定义一个stmt存放结果集
    sqlite3_stmt *stmt = NULL;
    
    // 3.检测SQL语句的合法性
    int result = sqlite3_prepare_v2(_db, sql, -1, &stmt, NULL);
    if (result == SQLITE_OK) {
        NSLog(@"查询语句是合法的");
        students = [NSMutableArray array];
        
        // 填补占位符的内容
        NSString *newCondition = [NSString stringWithFormat:@"%%%@%%", condition];
//        NSLog(@"%@", newCondition);
        sqlite3_bind_text(stmt, 1, newCondition.UTF8String, -1, NULL);
        
        // 4.执行SQL语句，从结果集中取出数据
        while (sqlite3_step(stmt) == SQLITE_ROW) { // 真的查询到一行数据
            // 获得这行对应的数据
            
            IWStudent *student = [[IWStudent alloc] init];
            
            // 获得第0列的id
            student.ID = sqlite3_column_int(stmt, 0);
            
            // 获得第1列的name
            const unsigned char *sname = sqlite3_column_text(stmt, 1);
            student.name = [NSString stringWithUTF8String:(const char *)sname];
            
            // 获得第2列的age
            student.age = sqlite3_column_int(stmt, 2);
            
            // 添加到数组
            [students addObject:student];
        }
    } else {
        NSLog(@"查询语句非合法");
    }
    
    return students;
}
@end

IWViewController.m

//
//  IWViewController.m
//  01-SQLite的基本使用
//
//  Created by apple on 14-5-22.
//  Copyright (c) 2014年 itcast. All rights reserved.
//

#import "IWViewController.h"
#import "IWStudent.h"
#import "IWStudentTool.h"

//Core Data : 苹果官方自带，可以让程序员不用写任何一句SQL
//FMDB

@interface IWViewController () <UISearchBarDelegate>

/*
- (IBAction)insert;
- (IBAction)update;
- (IBAction)delete;
- (IBAction)query;
*/

@property (nonatomic, strong) NSArray *students;
@end

@implementation IWViewController

- (NSArray *)students
{
    if (_students == nil) {
        _students = [IWStudentTool students];
    }
    return _students;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
    searchBar.delegate = self;
    self.tableView.tableHeaderView = searchBar;
}

#pragma mark - 搜索框代理
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    self.students = [IWStudentTool studentsWithCondition:searchText];
    [self.tableView reloadData];
}

#pragma mark - tableView代理方法
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return self.students.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    // 1.创建cell
    static NSString *ID = @"student";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:ID];
    }
    
    // 2.设置cell的数据
    IWStudent *stu = self.students[indexPath.row];
    cell.textLabel.text = stu.name;
    cell.detailTextLabel.text = [NSString stringWithFormat:@"%d", stu.age];
    
    return cell;
}

/*
- (IBAction)insert
{
    for (int i = 0; i<30; i++) {
        // 创建学生
        IWStudent *student = [[IWStudent alloc] init];
        student.name = [NSString stringWithFormat:@"Jack-%d", arc4random()%100];
        student.age = arc4random()%100;
        
        // 添加学生
        BOOL result = [IWStudentTool addStudent:student];
        
        if (result) {
            NSLog(@"添加成功");
        }
    }
}

- (IBAction)update
{

}

- (IBAction)delete
{
    
}

- (IBAction)query
{
    NSArray *students = [IWStudentTool students];
    
    for (IWStudent *stu in students) {
        NSLog(@"%d %@ %d", stu.ID, stu.name, stu.age);
    }
}
 */
@end