本文主要是介绍iOS学习 数据库 FMDB框架使用 UISearchBar搜索框 线程安全，事务，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
UISearchBar应用：
http://blog.csdn.net/sanpintian/article/details/7379996
#import "ViewController.h"
#import "FMDB.h"
@interface ViewController ()<UITableViewDataSource,UITableViewDelegate,UISearchBarDelegate>
@property (weak,nonatomic) IBOutletUITextField *name;
@property (weak,nonatomic) IBOutletUITextField *price;
@property (weak,nonatomic) IBOutletUITableView *tableView;
@property (nonatomic,retain)FMDatabase *db;
@property (nonatomic,retain)NSMutableArray *dataArray;
@end
@implementation ViewController
- (void)viewDidLoad {
[superviewDidLoad];
//打开数据库（如果不存在，直接新建数据库）
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES)lastObject]stringByAppendingPathComponent:@"shop.sqlite"];//沙盒路径拼接
NSLog(@"%@",path);
self.db = [FMDatabasedatabaseWithPath:path];
//打开数据库
[self.dbopen];
//创表
[self.dbexecuteUpdate:@"CREATE TABLE IF NOT EXISTS t_shop(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, price TEXT DEFAULT 100);"];
_dataArray = [NSMutableArrayarray];
self.tableView.dataSource =self;
self.tableView.delegate =self;
self.tableView.backgroundColor = [UIColor lightGrayColor];
UISearchBar *searchbar = [[UISearchBaralloc]initWithFrame:CGRectMake(0,0, self.tableView.frame.size.width,40)];
searchbar.delegate =self;
self.tableView.tableHeaderView = searchbar;
}
//监听搜索框内容变化
-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText{
[_dataArrayremoveAllObjects];
NSString *sql = [NSStringstringWithFormat:@"SELECT name,price FROM t_shop WHERE name LIKE '%%%@%%' OR price LIKE '%%%@%%'",searchText,searchText];
FMResultSet *set = [self.dbexecuteQuery:sql];
//不断往下取数据
while (set.next) {
//获取当前数据
NSMutableDictionary *dict = [NSMutableDictionarydictionary];
NSString *name = [setstringForColumn:@"name"];
NSString *price = [setstringForColumn:@"price"];
[dict setValue:nameforKey:@"name"];
[dict setValue:priceforKey:@"price"];
[_dataArrayaddObject: dict];
}
[self.tableViewreloadData];
}
//往数据库表中加入记录
- (IBAction)addRow:(id)sender {
//添加数据
[self.dbexecuteUpdateWithFormat:@"INSERT INTO t_shop(name, price) VALUES (%@,%@);",self.name.text,self.price.text];
}
//删除数据库表中特定条件记录
- (IBAction)deleteRow:(id)sender {
//删除
// [self.db executeUpdateWithFormat:@"DELETE FROM t_shop WHERE price = ''"];
//修改
[self.dbexecuteUpdateWithFormat:@"UPDATE t_shop SET name = 'iPhone5' WHERE name = '手机';"];
}
//刷新，将数据库表内容显示在tableView上
- (IBAction)refresh:(id)sender {
//得到结果集
FMResultSet *set = [self.dbexecuteQuery:@"SELECT * FROM t_shop;"];
//不断往下取数据
while (set.next) {
//获取当前数据
NSMutableDictionary *dict = [NSMutableDictionarydictionary];
NSString *name = [setstringForColumn:@"name"];
NSString *price = [setstringForColumn:@"price"];
NSLog(@"name %@",name);
[dict setValue:nameforKey:@"name"];
[dict setValue:priceforKey:@"price"];
[_dataArrayaddObject: dict];
}
NSLog(@"_dataArray:%@",_dataArray);
[self.tableViewreloadData];
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
return_dataArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
staticNSString *ID = @"shop";
UITableViewCell *cell = [tableViewdequeueReusableCellWithIdentifier:ID];
if (!cell) {
cell = [[UITableViewCellalloc]initWithStyle:UITableViewCellStyleValue1reuseIdentifier:ID];
}
NSDictionary *dict = [NSDictionarydictionary];
dict = _dataArray[indexPath.row];
cell.textLabel.text = dict[@"name"];
cell.detailTextLabel.text = dict[@"price"];
return cell;
}
#import "ViewController.h"
#import <sqlite3.h>
#import "FMDB.h"
@interface ViewController ()
@property (nonatomic, strong) FMDatabaseQueue *queue;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//1.线程安全
NSString *path = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)lastObject] stringByAppendingPathComponent:@"data.sqlite"];
FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:path];
self.queue = queue; //保证队列不消除
[self.queue inDatabase:^(FMDatabase *db) { //在block 内部的就是线程安全
BOOL success = [db open];
if (success) {
NSLog(@"创建数据库成功!");
//非查询语句都是用executeUpdate
BOOL successT= [db executeUpdate:@"CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT ,name TEXT NOT NULL , score REAL);"];
if (successT) {
NSLog(@"创建表成功!");
}else{
NSLog(@"创建表失败!!");
}
}else{
NSLog(@"创建失败!");
}
}];
}
- (IBAction)selctClick:(id)sender {
[self.queue inDatabase:^(FMDatabase *db) {
NSString *sql = @"SELECT id,name,score FROM t_student WHERE score > 60 AND score < 75;";
FMResultSet *result = [db executeQuery:sql];
while ([result next]) {
//name TEXT
NSString *name = [result stringForColumnIndex:1];
//score DOUBLE
double score = [result doubleForColumnIndex:2];
NSLog(@"name = %@ score = %f",name,score);
}
}];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
//修改
//UPDATE t_money SET MONEY = 8000 – 800 WHERE name =小明;
//UPDATE t_money SET MONEY = 8000 – 1800 WHERE name =小明;
[self.queue inDatabase:^(FMDatabase *db) {
//开启事务 在这条语句之后的都是一个事务
[db beginTransaction];
//UPDATE t_money SET MONEY = 8000 – 800 WHERE name =小明;
//UPDATE t_money SET MONEY = 8000 – 1800 WHERE name =小明;
[db rollback]; //自动回滚
[db commit];
//判断是否在事务中
if ([db inTransaction]) {
}
}];
}
- (IBAction)addClick:(id)sender {
[self.queue inDatabase:^(FMDatabase *db) {
for (int i = 0; i < 100; i++) {
NSString *name = [NSString stringWithFormat:@"xiaoli-%d",i];
NSString *sql = [NSString stringWithFormat:@"INSERT INTO t_student (name,score) VALUES ('%@',%f)",name,arc4random_uniform(8000)/100.0 + 20];
BOOL success = [db executeUpdate:sql];
if (success) {
NSLog(@"添加数据成功!");
}else{
NSLog(@"添加数据失败!!");
}
}
}];
}
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