云顶娱乐手机版-云顶娱乐v1.8

云顶娱乐手机版拥有更好的使用效果,云顶娱乐v1.8每天有上万玩家一起在线游戏,赶快加入吧,云顶娱乐手机版已经成为国内的少数几家集大型网络游戏研发与运营和社区服务为一体的全新互联网娱乐平台,佳网络线上娱乐城。

位运算举例权限制行驶使,mysql怎么着把四个表直

正文从哪些树立mysql索引以及介绍mysql的索引类型,再讲mysql索引的利与弊,以及创建目录时索要专一的地方

摘要:

 

 

一:在新表已经创设好的气象下

第一:先假若有一张表,表的数目有10W条数据,个中有一条数据是nickname='css',如若要拿那条数据的话要求些的sql是 SELECT * FROM award WHERE nickname = 'css'

下文通过举个例子的方法汇报sqlserver中位运算的相干文化,如下所示:
试验景况:sqlserver 2010 CRUISER2

一、创设数量库表

Preface

1,拷贝全数的字段

相似景观下,在并未有创设目录的时候,mysql须求扫描全表及扫描10W条数据找那条数据,假设我在nickname上确立目录,那么mysql只要求扫描一行数据及为我们找到那条nickname='css'的数码,是不是以为质量进步了不菲咧....


1.在指令行中步入MySQL数据库
我们的操作都以在指令行中实行的,所以有限支撑你能够进来命令行分界面(对于Windows,初始菜单--运营--输入cmd,就能够调出命令行分界面,Linux和MAC的就绝十分少说了。)
在命令行中进行如下的通令操作就足以进去到MySQL数据库中:
C:Windowssystem32> mysql -h localhost -u root -p

 

insert into new_table select * from old_table

mysql的目录分为单列索引(主键索引,唯索引,普通索引)和组合索引.

 

大旨的讲授如下:

    I supposed we are encountering a situation that there's an anonymous user has connected in our MySQL database with an account which has large privileges.The user is doing some query operations with bad performance.Which may subsequently lead to a high load of our database server.How to solve this issue efficiently and immediately?There's a little trick we can use below.

2,拷贝部分字段表

单列索引:二个索引只包蕴一个列,三个表能够有三个单列索引.

在sqlserver的权位设置,大家常见采纳1、2、4、8、16、32、64、128等数值分别代表有关消息的某一动静供职业意况使用,通过字段值之间的重组形成三个气象值存款和储蓄到数据库中,
安装一个角色有所的权杖
例:
1:代表“查看”开关权限
2:代表"修改"按钮
4:代表"导出"按钮
8:代表"删除"按钮
...

◆-h:后边接的是主机名,表示你要连接到哪台主机的MySQL数据库。

 

insert into new_table(id,name,sex) select id,name,sex from old_table

组合索引:一个组合索引满含五个或三个以上的列,

--例:
--权限表如下:
create table userRole(userId varchar(36),
roleInfo int);
go

insert into userRole(userId,roleInfo)values('test',1) ---初始化测试账号"test",拥有查看权限
insert into userRole(userId,roleInfo)values('猫猫',2) 
--当我们需要给用户加入修改"2"权限,则可以使用以下运算
update userRole set roleInfo =roleInfo|2 where userId ='test'


--当我们需要给用户加入导出"4"权限,则可以继续使用以下运算
update userRole set roleInfo =roleInfo|4 where userId ='test'


--当我们需要给用户删除导出"4"权限,则可以继续使用以下运算
--删除权限前需判断用户是否存在此权限,此脚本不可多次运行
--if exists (select null from userRole where roleInfo &4 =4 and userId ='test')
---begin
update userRole set roleInfo =roleInfo^4 where userId ='test' and roleInfo&4 =4 
--end
---我们检索所有拥有权限"修改2"的用户信息
select * from userRole where roleInfo &2 = 2

go
truncate table userRole
drop table userRole

◆-u:前边接的是客商名,MySQL暗中认可的正是root。

Example

3,拷贝部分的行

位运算举例权限制行驶使,mysql怎么着把四个表直接拷贝到贰个新的表。正文使用的案例的表

 

◆-p:内定需求使用密码登入MySQL数据库,就算密码为空,该参数能够总结。

云顶娱乐v1.8, 

insert into new_table select  *  from old_table where id="1"

CREATE TABLE `award` (
   `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户id',
   `aty_id` varchar(100) NOT NULL DEFAULT '' COMMENT '活动场景id',
   `nickname` varchar(12) NOT NULL DEFAULT '' COMMENT '用户昵称',
   `is_awarded` tinyint(1) NOT NULL DEFAULT 0 COMMENT '用户是否领奖',
   `award_time` int(11) NOT NULL DEFAULT 0 COMMENT '领奖时间',
   `account` varchar(12) NOT NULL DEFAULT '' COMMENT '帐号',
   `password` char(32) NOT NULL DEFAULT '' COMMENT '密码',
   `message` varchar(255) NOT NULL DEFAULT '' COMMENT '获奖信息',
   `created_time` int(11) NOT NULL DEFAULT 0 COMMENT '创建时间',
   `updated_time` int(11) NOT NULL DEFAULT 0 COMMENT '更新时间',
   PRIMARY KEY (`id`)
 ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COMMENT='获奖信息表';

注意事项:云顶娱乐手机版

详见的演说如下:

Create a test account.

4,拷贝部分的行和字段

(一)索引的成立

此间权限设置,主要使用二进制中每一个人代表二个权力及位运算的表征开展权力的增减操作
出于"^异或运算"运算,左表明式1或0 时 右表达式为1时,将独家发出 0、1,所以剔除权限制时间,必须要一口咬住不放是不是留存此权限
 转自:http://www.maomao365.com/?p=7137

前方大家在-h后边填写了localhost,表示的是要登录到当下主机的MySQL数据库,在这种景色下,-h参数以及localhost完全能够简简单单,也等于说,使用下边包车型大巴一声令下也是足以登录到本机的MySQL数据库的:

 1 (root@localhost mysql3306.sock)[(none)]>create user aaron8219@'192.168.1.%' identified by 'zlm';
 2 Query OK, 0 rows affected (0.00 sec)
 3 
 4 (root@localhost mysql3306.sock)[(none)]>select user,host from mysql.user;
 5 +---------------+-------------+
 6 | user          | host        |
 7 +---------------+-------------+
 8 | rpl_mgr       | %           |
 9 | aaron8219     | 192.168.1.% |
10 | repl          | 192.168.1.% |
11 | replica       | 192.168.1.% |
12 | zlm           | 192.168.1.% |
13 | mysql.session | localhost   |
14 | mysql.sys     | localhost   |
15 | root          | localhost   |
16 +---------------+-------------+
17 8 rows in set (0.00 sec)
18 
19 (root@localhost mysql3306.sock)[(none)]>grant all privileges on *.* to aaron8219@'192.168.1.%'; //Grant the supreme privileges to the user.
20 Query OK, 0 rows affected (0.00 sec)
21 
22 (root@localhost mysql3306.sock)[(none)]>show grants for aaron8219@'192.168.1.%';
23 +----------------------------------------------------------+
24 | Grants for aaron8219@192.168.1.%                         |
25 +----------------------------------------------------------+
26 | GRANT ALL PRIVILEGES ON *.* TO 'aaron8219'@'192.168.1.%' |
27 +----------------------------------------------------------+
28 1 row in set (0.00 sec)

insert into new_table(id,name,sex) select id,name,sex form old_table where id='1'

1.单列索引

2.查看已有个别数据库
得逞登入到MySQL数据库中之后,我们先是就来看一下,MySQL数据库中有稍许个数据库(你能够清楚为,MySQL数据库是三个大商旅,然后那个大货仓下边有四个小的旅舍,我们就在那个小仓房中贮存大家的数据),我们举办如下的操作:
mysql> show databases;

 

二:在新表还尚未建的事态下

1-1)    普通索引,这几个是最中心的目录,

3.开立自身的数据库*(create database 数据库名;)

**Connect to database with the new account.**

方案一:

其sql格式是 CREATE INDEX IndexName ON `TableName`(`字段名`(length)) 或者 ALTER TABLE TableName ADD INDEX IndexName(`字段名`(length))

接下去我们将要创立四个属于大家友好的数据库来保存数据了,看上面包车型地铁操作:
mysql> create database students_info;
Query OK, 1 row affected (0.01 sec)

 1 [root@zlm2 09:25:29 ~]
 2 #mysql -uaaron8219 -pzlm -h192.168.1.101
 3 mysql: [Warning] Using a password on the command line interface can be insecure.
 4 Welcome to the MySQL monitor.  Commands end with ; or g.
 5 Your MySQL connection id is 4
 6 Server version: 5.7.21-log MySQL Community Server (GPL)
 7 
 8 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
 9 
10 Oracle is a registered trademark of Oracle Corporation and/or its
11 affiliates. Other names may be trademarks of their respective
12 owners.
13 
14 Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
15 
16 (aaron8219@192.168.1.101 3306)[(none)]>show databases; //The user "aaron8219" can see all the databases in the current MySQL instance.
17 +--------------------+
18 | Database           |
19 +--------------------+
20 | information_schema |
21 | mysql              |
22 | performance_schema |
23 | sys                |
24 | sysbench           |
25 | zlm                |
26 +--------------------+
27 6 rows in set (0.01 sec)
28 
29 (aaron8219@192.168.1.101 3306)[(none)]>create database aaron8219;
30 Query OK, 1 row affected (0.00 sec)
31 
32 (aaron8219@192.168.1.101 3306)[(none)]>use aaron8219;
33 Database changed
34 (aaron8219@192.168.1.101 3306)[aaron8219]>create table t1(
35     -> id int,
36     -> name char(10)
37     -> ) engine=innodb;
38 Query OK, 0 rows affected (0.02 sec)

create table new_table (select * from old_table)

第一种艺术 :

这里大家成立了三个名称叫students_info的数据库,当见到有Query OK, 1 row affected (0.01 sec)时,就申明大家的数据库创立成功了.

 

这种方案建的话,只是拷贝的询问的结果,新表不会有主键和目录

  CREATE INDEX account_Index ON `award`(`account`);

4.4.选项要操作的数据库
(use 数据库名[;] 那时你应有潜心到,分号";"是放在中括号[]里的,也正是说,加不加分号都是能够的,那意味,你使用use students_info来进行数据库的精选也是可以的,但为了不便于混淆视听,建议依旧增进去好些吗。)

**Create another precise account which name is equal to the one above and with an intact ip address.**

方案二:

第三种方法: 

在地方的数据库中,并非每贰个都以大家必要实行操作的,大家只必要对大家正好创设的数据库students_info进行操作就足以了,可是,尽管要想操作那几个数据库,首先你就要告诉MySQL数据库系统,接下去你要利用students_info这一个数据库来张开连锁的操作,怎么着告诉系统啊?看上面的操作:
mysql> use students_info;
Database changed

 

create table new_table LIKE old_table

ALTER TABLE award ADD INDEX account_Index(`account`)

5.在数据库中创建数量库表(create table 数据库表名(列证明);)

 1 (root@localhost mysql3306.sock)[(none)]>create user aaron8219@'192.168.1.101' identified by 'zlm';
 2 Query OK, 0 rows affected (0.00 sec)
 3 
 4 (root@localhost mysql3306.sock)[(none)]>select user,host from mysql.user;
 5 +---------------+---------------+
 6 | user          | host          |
 7 +---------------+---------------+
 8 | rpl_mgr       | %             |
 9 | aaron8219     | 192.168.1.%   |
10 | repl          | 192.168.1.%   |
11 | replica       | 192.168.1.%   |
12 | zlm           | 192.168.1.%   |
13 | aaron8219     | 192.168.1.101 |
14 | mysql.session | localhost     |
15 | mysql.sys     | localhost     |
16 | root          | localhost     |
17 +---------------+---------------+
18 9 rows in set (0.00 sec)
19 
20 (root@localhost mysql3306.sock)[(none)]>grant all privileges on aaron8219.* to aaron8219@'192.168.1.101'; //Grant the privileges only on "aaron8219" database.
21 Query OK, 0 rows affected (0.00 sec)
22 
23 (root@localhost mysql3306.sock)[(none)]>show grants for aaron8219@'192.168.1.101';
24 +----------------------------------------------------------------------+
25 | Grants for aaron8219@192.168.1.101                                   |
26 +----------------------------------------------------------------------+
27 | GRANT USAGE ON *.* TO 'aaron8219'@'192.168.1.101'                    |
28 | GRANT ALL PRIVILEGES ON `aaron8219`.* TO 'aaron8219'@'192.168.1.101' |
29 +----------------------------------------------------------------------+
30 2 rows in set (0.00 sec)

该方案不得不拷贝表结构到新表中,不会拷贝数据

 

mysql> create table network3
-> (
-> id char(10) not null primary key,
-> name char(16) not null,
-> sex char(6) not null,
-> age int not null,
-> address char(36) not null
-> );

 

方案三:

 

a.创设一列,名叫id;数据类型为char字符类型,字符的最大尺寸为十三个字符;何况该列内容不容许为空;同不经常间把这一列作为那张表的主键,用来分别表中不一致行。

Connect to database with the account again.

一旦要真正的复制叁个数量到新表,大家得以向来实践下边包车型地铁口舌

 

b.创立一列,名称叫name;数据类型为char字符类型,字符的最大尺寸为14个字符;并且该列内容不允许为空。

 1 [root@zlm2 09:32:57 ~]
 2 #mysql -uaaron8219 -pzlm -h192.168.1.101
 3 mysql: [Warning] Using a password on the command line interface can be insecure.
 4 Welcome to the MySQL monitor.  Commands end with ; or g.
 5 Your MySQL connection id is 5
 6 Server version: 5.7.21-log MySQL Community Server (GPL)
 7 
 8 Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
 9 
10 Oracle is a registered trademark of Oracle Corporation and/or its
11 affiliates. Other names may be trademarks of their respective
12 owners.
13 
14 Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
15 
16 (aaron8219@192.168.1.101 3306)[(none)]>show databases; //Only the "aaron8219" database can be list.
17 +--------------------+
18 | Database           |
19 +--------------------+
20 | information_schema |
21 | aaron8219          |
22 +--------------------+
23 2 rows in set (0.00 sec)
24 
25 (aaron8219@192.168.1.101 3306)[(none)]>show grants for aaron8219@'192.168.1.101';
26 +----------------------------------------------------------------------+
27 | Grants for aaron8219@192.168.1.101                                   |
28 +----------------------------------------------------------------------+
29 | GRANT USAGE ON *.* TO 'aaron8219'@'192.168.1.101'                    |
30 | GRANT ALL PRIVILEGES ON `aaron8219`.* TO 'aaron8219'@'192.168.1.101' |
31 +----------------------------------------------------------------------+
32 2 rows in set (0.00 sec)
33 
34 (aaron8219@192.168.1.101 3306)[(none)]>use aaron8219;
35 Reading table information for completion of table and column names
36 You can turn off this feature to get a quicker startup with -A
37 
38 Database changed
39 (aaron8219@192.168.1.101 3306)[aaron8219]>show tables;
40 +---------------------+
41 | Tables_in_aaron8219 |
42 +---------------------+
43 | t1                  |
44 +---------------------+
45 1 row in set (0.00 sec)
46 
47 (aaron8219@192.168.1.101 3306)[aaron8219]>insert into t1 values(1,'abc');
48 Query OK, 1 row affected (0.00 sec)
49 
50 (aaron8219@192.168.1.101 3306)[aaron8219]>select * from t1;
51 +------+------+
52 | id   | name |
53 +------+------+
54 |    1 | abc  |
55 +------+------+
56 1 row in set (0.00 sec)
57 
58 //Eventrually,the privileges of account aaron8219@'192.168.1.%' has been restricted merely on database "aaron8219".
59 //Further more,we can revoke all the privileges on it either.

create table new_table LIKE old_table;

本文由云顶娱乐手机版发布于云顶娱乐,转载请注明出处:位运算举例权限制行驶使,mysql怎么着把四个表直

TAG标签:
Ctrl+D 将本页面保存为书签,全面了解最新资讯,方便快捷。