fmdb是基于sqlite3基礎上進行封裝,概念性的東西不多說,本demo采用的是隊列方式,可以保證線程安全
demo演示
//主要代碼:事務回滾,有興趣的朋友可以自行添加
@implementation DBObject
+(instancetype)sharedInstance{
static DBObject *sql = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sql = [[DBObject alloc]init];
});
return sql;
}
/**
* 初始化字典
*
* @return <#return value description#>
*/
-(NSMutableDictionary *)params{
if (!_params) {
_params = [NSMutableDictionary dictionary];
}
return _params;
}
/**
* 初始化數組(查找全部)
*
* @return <#return value description#>
*/
-(NSMutableArray *)Array{
if (!_Array) {
_Array = [NSMutableArray array];
}
return _Array;
}
/**
* 新建數據庫+新建表
*/
-(void)addDatabaseAndTableMethod{
NSString *cachePath = [NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES)firstObject];
//拼接文件名
NSString *filePath = [cachePath stringByAppendingString:@"note.sqlite"];
NSLog(@"數據庫路徑:%@",filePath);
//創建數據庫,并加入到隊列中,此時已經默認打開了數據庫,無須手動打開,只需要從隊列中去除數據庫即可
self.queue = [FMDatabaseQueue databaseQueueWithPath:filePath];
//取出數據庫,這里的db就是數據庫,在數據庫中建表
[self.queue inDatabase:^(FMDatabase *db) {
BOOL createTable = [db executeUpdate:@"create table if not exists t_note (id integer primary key autoincrement,title text,name text,password text)"];
if (createTable) {
NSLog(@"創建表成功");
}
else{
NSLog(@"創建表失敗");
}
}];
}
/**
* 新增
*/
-(void)insetTitle:(NSString *)title WithName:(NSString *)name WithPassWord:(NSString *)password{
[self.queue inDatabase:^(FMDatabase *db) {
BOOL flag = [db executeUpdate:@"insert into t_note (title,name,password) values (?,?,?)",title,name,password];
if (flag) {
NSLog(@"新增數據成功");
}
else{
NSLog(@"新增數據失敗");
}
}];
}
/**
* 刪除
*/
-(void)deleteWithTitle:(NSString *)title{
[self.queue inDatabase:^(FMDatabase *db) {
BOOL flag = [db executeUpdate:@"delete from t_note where title = ?",title];
if (flag) {
NSLog(@"刪除數據成功");
}
else{
NSLog(@"刪除數據失敗");
}
}];
}
/**
* 更新數據
*/
-(void)updateWithNewName:(NSString *)newName WithTitle:(NSString *)title{
[self.queue inDatabase:^(FMDatabase *db) {
BOOL flag = [db executeUpdate:@"update t_note set name = ? where title = ?",newName,title];
if (flag) {
NSLog(@"更新數據成功");
}
else{
NSLog(@"更新數據失敗");
}
}];
}
/**
* 條件查詢數據
*/
-(void)selectWithTitle:(NSString *)title{
[self.queue inDatabase:^(FMDatabase *db) {
//獲取結果集,返回參數就是查詢結果
FMResultSet *rs = [db executeQuery:@"select *from t_note where title = ?",title];
while ([rs next]) {
self.title = [rs stringForColumn:@"title"];
self.name = [rs stringForColumn:@"name"];
self.password = [rs stringForColumn:@"password"];
NSLog(@"平臺:%@---用戶名:%@----密碼:%@",self.title,self.name,self.password);
//先將數據存放到字典
NSMutableDictionary *dic = [NSMutableDictionary dictionary];
[dic setObject:self.title forKey:@"dictTitle"];
[dic setObject:self.name forKey:@"dictName"];
[dic setObject:self.password forKey:@"dictPwd"];
//然后將字典存放到數組
[self.Array addObject:dic];
}
}];
}
/**
* 查詢所有數據
*
*/
-(void)selectAllMethod{
//每次進來查詢的時候,先清除上次緩存數據
[self.Array removeAllObjects];
[self.queue inDatabase:^(FMDatabase *db) {
//獲取結果集,返回參數就是查詢結果
FMResultSet *rs = [db executeQuery:@"select *from t_note"];
while ([rs next]) {
self.title = [rs stringForColumn:@"title"];
self.name = [rs stringForColumn:@"name"];
self.password = [rs stringForColumn:@"password"];
NSLog(@"平臺:%@---用戶名:%@----密碼:%@",self.title,self.name,self.password);
//先將數據存放到字典
NSMutableDictionary *dic = [NSMutableDictionary dictionary];
[dic setObject:self.title forKey:@"dictTitle"];
[dic setObject:self.name forKey:@"dictName"];
[dic setObject:self.password forKey:@"dictPwd"];
//然后將字典存放到數組
[self.Array addObject:dic];
}
NSLog(@"存放的數組:%@==%ld",self.Array,self.Array.count);
[[NSUserDefaults standardUserDefaults]setObject:self.Array forKey:@"Arry"];
[[NSUserDefaults standardUserDefaults]synchronize];
}];
}
/**
* 事務回滾寫法1: (如果要保證多個操作同時成功或者同時失敗，用事務，即把多個操作放在同一個事務中。)
*/
-(void)updateFailure:(id)sender{
[self.queue inDatabase:^(FMDatabase *db) {
[db beginTransaction];
[db executeUpdate:@"update t_note set name = 'jack' where password = ?",@"12"];
[db executeUpdate:@"update t_note set name = 'tony' where password = ?",@"13"];
//發現情況不對,主動回滾用下面語句.否則是根據commit結果,如成功就成功，如不成功才回滾
[db rollback];
[db executeUpdate:@"update t_note set name = '回滾' where password = ?",@"13"];
[db commit];
}];
}
/**
* 事務回滾寫法2:(直接利用隊列進行事務操作,隊列中的打開、關閉、回滾事務等都已經被封裝好了)
*/
-(void)updateFailure02:(id)sender{
[self.queue inDatabase:^(FMDatabase *db) {
[self.queue inTransaction:^(FMDatabase *db, BOOL *rollback) {
[db executeUpdate:@"update t_note set name = 'jack' where password = ?",@"12"];
[db executeUpdate:@"update t_note set name = 'tony' where password = ?",@"13"];
//發現情況不對,主動回滾用下面語句
*rollback = YES;
[db executeUpdate:@"update t_note set name = '回滾' where password = ?",@"13"];
}];
}];
}
/**
* 回滾的原生代碼:
[db executeUpdate:@"BEGIN TRANSACTION"];
[db executeUpdate:@"ROLLBACK TRANSACTION"];
[db executeUpdate:@"COMMIT TRANSACTION"];
*/
demo鏈接:https://github.com/OwenJoe/FMDB.git
iOS開發之FMDB圖片的增刪查改,請參閱:
鏈接:http://www.lxweimin.com/p/6edcfe58aaf0
