iOS个人整理42-FMDB

来源：互联网发布：剑三淘宝编辑：程序博客网时间：2024/05/27 14:14

创建FMDatabas对象时参数为SQLite数据库文件路径，该路径可以是一下三种方法之一

1.文件路径。该文件路径无需真实存在，如果不存在会自动创建

2.空字符串@”“，表示会在临时目录创建一个空的数据库，当FMDatabase连接关闭时，文件也会被删除。

3.NULL。将创建一个内在数据库，同样，当FMDatabase连接关闭时，数据将被销毁

FMDB的使用

//得到沙盒地址方法-(NSString*)sandBox{    NSArray *docArray = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *path = docArray[0];    NSString *filePath = [path stringByAppendingPathComponent:@"fmdb.sqlite"];    return filePath;}//fmdb打开数据库和建表-(void)openAndCreat{    //得到数据库对象    FMDatabase *db = [FMDatabase databaseWithPath:[self sandBox]];    BOOL isOpen = [db open];    if (isOpen) {        NSLog(@"db ok");        //建表，所有无返回集的操作都可以用update来执行sql语句，返回值为bool，判断操作成功        BOOL isCreat = [db executeUpdate:@"CREATE TABLE IF NOT EXISTS myFMDB (id integer PRIMARY KEY AUTOINCREMENT,name text NOT NULL,age integer NOT NULL DEFAULT 0)"];        if (isCreat) {            NSLog(@"table ok");        }        else        {//建表失败            [db lastError];            NSLog(@"table fs");        }    }    else    {        NSLog(@"db fs");    }}//增加数据-(void)insertData{    //得到实例对象    FMDatabase *db = [FMDatabase databaseWithPath:[self sandBox]];    //先关闭    [db close];    if ([db open]) {        //打开成功，插入数据        NSInteger age = [_ageTextField.text integerValue];        //两种方式        //使用update传参，占位符为?，参数值必须为对象        BOOL isExe = [db executeUpdate:@"INSERT INTO myFMDB (name,age)values(?,?)",_nameTextField.text,@(age)];        //使用updateWithFormat，占位符%@等        BOOL isExe2 = [db executeUpdateWithFormat:@"INSERT INTO myFMDB (name,age)values(%@,%d)",@"王",11];        if (isExe && isExe2) {            NSLog(@"insert ok");        }    }}//搜索方法-(void)queryData{    FMDatabase *db = [FMDatabase databaseWithPath:[self sandBox]];    [db open];    //执行查询    FMResultSet *result = [db executeQuery:@"SELECT * FROM myFMDB"];   //存储查询结果    _resultMArray = [[NSMutableArray alloc]init];    //循环获得结果集    //next 为ture时继续取下一条    while ([result next]) {        NSString *name = [result stringForColumn:@"name"];        NSInteger age = [result intForColumn:@"age"];        NSInteger id = [result intForColumn:@"id"];        NSLog(@"id = %ld,name = %@,age = %ld",id,name,age);        NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:name,@"name",@(age),@"age",@(id),@"id",nil];        [_resultMArray addObject:dic];    }    //释放结果集    [result close];    //搜索表里的记录数    [db executeQuery:@"select count(*) from myFMDB"];    //关数据库    [db close];}//单个字段值的查询-(void)querySumRow{    FMDatabase *db = [FMDatabase databaseWithPath:[self sandBox]];    if ([db open]) {        int sumRow = [db intForQuery:@"select age from myFMDB where id = 5"];        int sumRow2 = [db intForQuery:@"select count(*) from myFMDB"];        NSLog(@"%d,%d",sumRow,sumRow2);    }   }

FMDB多线程方法

//调用多线程方法-(void)beginThread{    NSDateFormatter *formatter = [[NSDateFormatter alloc]init];    [formatter setDateFormat:@"yy-MM-dd,hh:mm:ss.SSS"];    //开始时间    NSLog(@"%@",[formatter stringFromDate:[NSDate date]]);    //建表    [self createSecondTable];    //两种方法        [self threads];    //    [self threadsSecond];不使用事务    //插入操作    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{        [self threadsSecond];        NSLog(@"%@",[NSThread currentThread]);        dispatch_async(dispatch_get_main_queue(), ^{            NSLog(@"这里是主线程--%@",[NSThread currentThread]);        });    });    //结束时间    NSLog(@"%@",[formatter stringFromDate:[NSDate date]]);}#pragma mark -- 多线程-(void)threads{    //创建队列    FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:[self sandBox]];    __block BOOL isError = NO;    //使用事务的方式处理多个操作,不需要手动打开或关闭数据库    [queue inTransaction:^(FMDatabase *db, BOOL *rollback) {        //回滚，从错误操作开始回滚到正确的操作        for (int i = 0 ; i < 100000; i++) {            NSString *sql = @"insert into stu (name,age,gender)values(?,?,?);";            //插入操作            isError = [db executeUpdate:sql,@"飞燕",@(i),@"女"];        }        if (!isError) {            NSLog(@"insert fs");            *rollback = YES;//插入出错，回滚到上次正确的地方;        }    }];}//不使用事物处理多线程-(void)threadsSecond{    //得到队列    FMDatabaseQueue *queue = [FMDatabaseQueue databaseQueueWithPath:[self sandBox]];    __block BOOL isError = NO;    //不使用事务的多线程操作    [queue inDatabase:^(FMDatabase *db) {//        [db beginTransaction];//开始事务        for (int i = 0 ; i < 1000; i++) {            NSString *sql = @"insert into stu (name,age,gender)values(?,?,?);";            //插入操作            isError = [db executeUpdate:sql,@"飞燕",@(i),@"女"];        }        if (!isError) {            NSLog(@"insert fs");        }//        [db commit];//事务提交        NSLog(@"%@",[NSThread currentThread]);    }];    //上面是gcd同步队列    //关闭动画    dispatch_async(dispatch_get_main_queue(), ^{        //刷新UI要写在主线程        [self.loadV stopAnimation];            });}

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