一.添加类
二.打开数据库
三.创表
四.插入数据
五.取出数据
一.添加类
1.在设置Linked Frameworks and Libraries 中,点加号并添加libsqlite3.0.dylib.
2.在控制器.m文件中,添加头文件#import<sqlite3.h>
二.打开数据库
sqlite3 *db = NULL;//创建数据库对象实例
int status = sqlite3_open(filename.UTF8String, &db);//打开数据库,返回的是bool类型。记得将OC转为c语言
三.创表
//squlite3_exec(sqlite3 *, const char *sql,int(*callback)(void *,int,char **),void *,char **errmsg);//一般用在没有返回值
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);
四.插入数据
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
五.取出数据
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];
六.模糊查询
a.增加搜索框
b.设置代理<UISearchBarDelegate>
searchBar.delegeta = self;
c.实现- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
D.数据库语句NSString *sql = [NSString stringWithFormat:@"SELECT name,price FROM t_shop WHERE name LIKE '%%%@%%' OR price LIKE '%%%@%%' ;", searchText, searchText];
代码:
#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