iOS-FMDatabase 数据库

pragma mark - 打开创建数据库

NSString *path = [NSString stringWithFormat:@"%@/Documents/record.rdb",NSHomeDirectory()];

    _database = [[FMDatabase alloc]initWithPath:path];

    if(!_database.open)

    {

        NSLog(@"打开数据库失败");

        return;

    }

pragma mark - 创建数据库中的表

-(void)testCreateTable
{
    //创建表
    //学生信息
    //  学号sid, 姓名username, 密码password, 成绩score
    NSString *sql = @"CREATE TABLE IF NOT EXISTS studentInfo(sid INTEGER,username varchar(32),password varchar(32),score INTEGER)";
    
    //执行查询语句
    //执行SELECT, 使用executeQuery
    //_databse executeQuery:<#(NSString *), ...#>
    
    //除了查询语句, 其他语句使用executeUpdate执行
    BOOL b = [_databse executeUpdate:sql];
    NSLog(@"Create table is %d",b);
}

pragma mark - 修改数据

-(void)testUpdateData
{
    //实例: 重置密码 为 123456
    NSString *username = @"asan";
    NSString *newPassword = @"123456";
    NSString *sql = @"UPDATE studentInfo SET password = ? WHERE username = ?";
    BOOL b = [_databse executeUpdate:sql,newPassword,username];
    NSLog(@"UPDATE b = %d",b);
}

pragma mark - 删除数据

-(void)testDeleteData
{
    //实例: 删除pangzi这条数据
    NSString *username = @"pangzi";
    NSString *sql = @"DELETE FROM studentInfo WHERE username = ?";
    BOOL b = [_databse executeUpdate:sql,username];
    NSLog(@"DELETE b = %d",b);
}

pragma mark - 查询数据

-(void)testQueryData
{
    //查询所有数据, 显示所有数据
    NSString *sql = @"SELECT * FROM studentInfo";
    
    //执行查询语句
    //注意: 查询完之后返回一个结果集
    //    结果集:  立即为二维数组, EXCEL表格
    FMResultSet *resultSet = [_databse executeQuery:sql];
    //注意: 取得每一行使用[resultSet next];
    //  取到一行返回YES, 最后一行取完之后在执行返回NO
    while ([resultSet next]) {
        //第一行数据: 1  asan 1314 58
        int sid = [resultSet intForColumn:@"sid"];
        NSString *name = [resultSet stringForColumn:@"username"];
        NSString *password = [resultSet stringForColumn:@"password"];
        int score = [resultSet intForColumn:@"score"];
        NSLog(@"sid = %d, name = %@ pass = %@, score = %d",sid,name,password,score);
    }
    
    
    
}

pragma mark - 插入数据

-(void)testInsertData
{
    int sid = 1024;
    NSString *username = @"pangzi";
    NSString *password = @"1315";
    int score = 58;
    
    //FMDB中?作为数据占位符, 和%d类似
    NSString *sql = @"INSERT INTO studentInfo(sid,username,password,score) VALUES(?,?,?,?)";
    //特别注意:  ?处需要的时字符串, 其他数据转化为字符串传入
    BOOL b = [_databse executeUpdate:sql,
            [NSString stringWithFormat:@"%d",sid],
            username,
            password,
            [NSString stringWithFormat:@"%d",score]];
    NSLog(@"INSERT b = %d",b);

}

HTTP/1.1 200 OK Server: Tengine Date: Fri, 11 Sep 2015 01:45:12 GMT Content-Type: text/html; charset=UTF-8 Content-Length: 50928 Connection: keep-alive Vary: Accept-Encoding Pragma: no-cache Cache-Control: no-cache, no-store, must-revalidate Expires: Thu, 01 Jan 1970 00:00:00 GMT Content-Language: en-US Cache-Control: no-cache