数据库 第三方库FMDB 使用

---恢复内容开始---

FMDB 为第三方库，可以在github上下载地址
https://github.com/ccgus/fmdb
使用fmdb的时候先在xcode上添加sqline3 库



在jithub上下载的包后将fmdb文件夹添加xode上中去

新建项目倒入头文件FMDB.hhttps://github.com/ccgus/fmdb即可

项目实践

---恢复内容结束---

FMDB 为第三方库，可以在github上下载地址
https://github.com/ccgus/fmdb
使用fmdb的时候先在xcode上添加sqline3 库



在jithub上下载的包后将fmdb文件夹添加xode上中去

新建项目倒入头文件FMDB.hhttps://github.com/ccgus/fmdb即可

项目实践

未使用 fmdb 第三方库的使用

#import "HMViewController.h"
#import <sqlite3.h>
#import "HMShop.h"

@interface HMViewController () <UITableViewDataSource, UISearchBarDelegate>
@property (weak, nonatomic) IBOutlet UITextField *nameField;
@property (weak, nonatomic) IBOutlet UITextField *priceField;
/** 数据库对象实例 */
@property (nonatomic, assign) sqlite3 *db;
@property (weak, nonatomic) IBOutlet UITableView *tableView;
- (IBAction)insert;
@property (nonatomic, strong) NSMutableArray *shops;
@end

@implementation HMViewController

- (NSMutableArray *)shops
{
if (!_shops) {
self.shops = [[NSMutableArray alloc] init];
}
return _shops;
}

- (void)viewDidLoad
{
[super viewDidLoad];

// 增加搜索框
UISearchBar *searchBar = [[UISearchBar alloc] init];
searchBar.frame = CGRectMake(0, 0, 320, 44);
searchBar.delegate = self;
self.tableView.tableHeaderView = searchBar;

// 初始化数据库
[self setupDb];

// 查询数据
[self setupData];

// 关闭数据库
//    sqlite3_close();
}

#pragma mark - UISearchBarDelegate
- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
[self.shops removeAllObjects];

NSString *sql = [NSString stringWithFormat:@"SELECT name,price FROM t_shop WHERE name LIKE '%%%@%%' OR  price LIKE '%%%@%%' ;", searchText, searchText];
// stmt是用来取出查询结果的
sqlite3_stmt *stmt = NULL;
// 准备
int status = sqlite3_prepare_v2(self.db, sql.UTF8String, -1, &stmt, NULL);
if (status == SQLITE_OK) { // 准备成功 -- SQL语句正确
while (sqlite3_step(stmt) == SQLITE_ROW) { // 成功取出一条数据
const char *name = (const char *)sqlite3_column_text(stmt, 0);
const char *price = (const char *)sqlite3_column_text(stmt, 1);

HMShop *shop = [[HMShop alloc] init];
shop.name = [NSString stringWithUTF8String:name];
shop.price = [NSString stringWithUTF8String:price];
[self.shops addObject:shop];
}
}

[self.tableView reloadData];
}

/**
查询数据
*/
- (void)setupData
{
const char *sql = "SELECT name,price FROM t_shop;";
// stmt是用来取出查询结果的
sqlite3_stmt *stmt = NULL;
// 准备
int status = sqlite3_prepare_v2(self.db, sql, -1, &stmt, NULL);
if (status == SQLITE_OK) { // 准备成功 -- SQL语句正确
while (sqlite3_step(stmt) == SQLITE_ROW) { // 成功取出一条数据
const char *name = (const char *)sqlite3_column_text(stmt, 0);
const char *price = (const char *)sqlite3_column_text(stmt, 1);

HMShop *shop = [[HMShop alloc] init];
shop.name = [NSString stringWithUTF8String:name];
shop.price = [NSString stringWithUTF8String:price];
[self.shops addObject:shop];
}
}
}

/**
初始化数据库
*/
- (void)setupDb
{
// 打开数据库(连接数据库)
NSString *filename = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"shops.sqlite"];
// 如果数据库文件不存在, 系统会自动创建文件自动初始化数据库
int status = sqlite3_open(filename.UTF8String, &_db);
if (status == SQLITE_OK) { // 打开成功
NSLog(@"打开数据库成功");

// 创表
const char *sql = "CREATE TABLE IF NOT EXISTS t_shop (id integer PRIMARY KEY, name text NOT NULL, price real);";
char *errmsg = NULL;
sqlite3_exec(self.db, sql, NULL, NULL, &errmsg);
if (errmsg) {
NSLog(@"创表失败--%s", errmsg);
}
} else { // 打开失败
NSLog(@"打开数据库失败");
}
}

- (IBAction)insert {
NSString *sql = [NSString stringWithFormat:@"INSERT INTO t_shop(name, price) VALUES ('%@', %f);", self.nameField.text, self.priceField.text.doubleValue];
sqlite3_exec(self.db, sql.UTF8String, NULL, NULL, NULL);

// 刷新表格
HMShop *shop = [[HMShop alloc] init];
shop.name = self.nameField.text;
shop.price = self.priceField.text;
[self.shops addObject:shop];
[self.tableView reloadData];
}

#pragma mark - 数据源方法
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return self.shops.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *ID = @"shop";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:ID];
cell.backgroundColor = [UIColor grayColor];
}

HMShop *shop = self.shops[indexPath.row];
cell.textLabel.text = shop.name;
cell.detailTextLabel.text = shop.price;

return cell;
}
@end

使用FMDB第三方库

HMShopTool.h 未做操作

HMShopTool.m

#import "HMShopTool.h"
#import "FMDB.h"
#import "HMShop.h"

@implementation HMShopTool

static FMDatabase *_db;

+ (void)initialize
{
// 1.打开数据库
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"shops.sqlite"];
_db = [FMDatabase databaseWithPath:path];
[_db open];

// 2.创表
[_db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_shop (id integer PRIMARY KEY, name text NOT NULL, price real);"];
}

+ (void)addShop:(HMShop *)shop
{
[_db executeUpdateWithFormat:@"INSERT INTO t_shop(name, price) VALUES (%@, %f);", shop.name, shop.price];
}

+ (NSArray *)shops
{// 得到结果集
FMResultSet *set = [_db executeQuery:@"SELECT * FROM t_shop;"];

// 不断往下取数据
NSMutableArray *shops = [NSMutableArray array];
while (set.next) {
// 获得当前所指向的数据
HMShop *shop = [[HMShop alloc] init];
shop.name = [set stringForColumn:@"name"];
shop.price = [set doubleForColumn:@"price"];
[shops addObject:shop];
}
return shops;
}
@end

创建模型

HMShop.h

HMShop.m未做操作

#import <Foundation/Foundation.h>

@interface HMShop : NSObject
@property (nonatomic, copy) NSString *name;
@property (nonatomic, assign) double  price;
@end

//在viewcontroller中使用fmdb的工具，只需导入把fmdb中去的HMShopTool.h即可，用法

#import "HMViewController.h"
//#import "FMDB.h"
#import "HMShop.h"
#import "HMShopTool.h"

@interface HMViewController ()
//@property (nonatomic, strong) FMDatabase *db;
@end

@implementation HMViewController

- (void)viewDidLoad
{
[super viewDidLoad];

// 1.打开数据库
//    NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject] stringByAppendingPathComponent:@"shops.sqlite"];
//    self.db = [FMDatabase databaseWithPath:path];
//    [self.db open];
//
//    // 2.创表
//    [self.db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_shop (id integer PRIMARY KEY, name text NOT NULL, price real);"];
// executeQuery:查询数据
//    [self.db executeQuery:<#(NSString *), ...#>];

// executeUpdate:除查询数据以外的其他操作
//    [self.db executeUpdate:<#(NSString *), ...#>];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{

//取出模型
NSArray *shops = [HMShopTool shops];

//转模型
for (HMShop *shop in shops) {
NSLog(@"%@ %f", shop.name, shop.price);
}

}
@end