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                    最后登录:2025-10-31 15:35<注册时间:2012-8-31 12:10阅读权限:200UID:1在线时间:1644 小时 
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mysql> select 1<<3;
+------+
| 1<<3 |
+------+
|    8 |
+------+
1 row in set (0.02 sec)
mysql> select 1<<10;
+-------+
| 1<<10 |
+-------+
|  1024 |
+-------+
1 row in set (0.00 sec)
mysql> select 1<<20;
+---------+
| 1<<20   |
+---------+
| 1048576 |
+---------+
1 row in set (0.00 sec)
mysql> select 1|2;
+-----+
| 1|2 |
+-----+
|   3 |
+-----+
1 row in set (0.00 sec)
mysql> select 1&2;
+-----+
| 1&2 |
+-----+
|   0 |
+-----+
1 row in set (0.00 sec)
mysql> select 5&6;
+-----+
| 5&6 |
+-----+
|   4 |
+-----+
1 row in set (0.00 sec)
--创建数据库
mysql> create database fooknet;
Query OK, 1 row affected (0.00 sec)
--查看当前用户可以看到所有数据库
mysql> show databases;
+----------------------+
| Database             |
+----------------------+
| information_schema   |
| test                 |
| mysql                |
| fooknet               |
+----------------------+
83 rows in set (0.75 sec)
--删除数据库
mysql> drop database fooknet;
Query OK, 0 rows affected (0.03 sec)
mysql> create database fooknet;
Query OK, 1 row affected (0.00 sec)
mysql>
-- 选择进入fooknet数据库
mysql> use fooknet;
Database changed
--查看当前你在哪个数据库下
mysql> select database();
+------------+
| database() |
+------------+
| fooknet     |
+------------+
1 row in set (0.00 sec)
--查看当前数据库中的所有表格。
mysql> show tables;
Empty set (0.02 sec)
mysql>
--创建留言表格
mysql> create table liuyan(
    -> id int unsigned not null auto_increment primary key,
    -> title varchar(32) not null,
    -> author varchar(32) not null default 'wu',
    -> addtime datetime,
    -> content text not null);
Query OK, 0 rows affected (0.08 sec)
--id 整型 无负号 非空 自增 主键(非空,唯一性、索引列)
--title 字串(长度32位) 非空
--author 字串(长度32位) 非空 默认值 “wu”
--查看留言表结构
mysql> desc liuyan;
+---------+------------------+------+-----+---------+----------------+
| Field   | Type             | Null | Key | Default | Extra          |
+---------+------------------+------+-----+---------+----------------+
| id      | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title   | varchar(32)      | NO   |     | NULL    |                |
| author  | varchar(32)      | NO   |     | wu      |                |
| addtime | datetime         | YES  |     | NULL    |                |
| content | text             | NO   |     | NULL    |                |
+---------+------------------+------+-----+---------+----------------+
5 rows in set (0.02 sec)
--以文本方式输出留言表的建表语句
mysql> show create table liuyan \G;
*************************** 1. row ***************************
       Table: liuyan
Create Table: CREATE TABLE `liuyan` (
  `id` int(10) unsigned NOT NULL auto_increment,
  `title` varchar(32) NOT NULL,
  `author` varchar(32) NOT NULL default 'wu',
  `addtime` datetime default NULL,
  `content` text NOT NULL,
  PRIMARY KEY  (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
ERROR:
No query specified
mysql>
mysql>
--查看当前数据库中表格
mysql> show tables;
+------------------+
| Tables_in_fooknet |
+------------------+
| liuyan           |
+------------------+
1 row in set (0.00 sec)
mysql>
--删除表格liuyan
mysql> drop table liuyan;
Query OK, 0 rows affected (0.00 sec)
mysql>  CREATE TABLE `liuyan` (
    ->   `id` int(10) unsigned NOT NULL auto_increment,
    ->   `title` varchar(32) NOT NULL,
    ->   `author` varchar(32) NOT NULL default 'wu',
    ->   `addtime` datetime default NULL,
    ->   `content` text NOT NULL,
    ->   PRIMARY KEY  (`id`)
    -> ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.05 sec)
mysql>
--添加一个测试表格
mysql> create table aa(id int not null);
Query OK, 0 rows affected (0.05 sec)
--查看当前数据库下的表格
mysql> show tables;
+------------------+
| Tables_in_fooknet |
+------------------+
| aa               |
| liuyan           |
+------------------+
2 rows in set (0.00 sec)
--删除一个不存在的表格
mysql> drop table bb;
ERROR 1051 (42S02): Unknown table 'bb'
--删除不存在的bb表,不报错
mysql> drop table if exists bb;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> drop table if exists aa;
Query OK, 0 rows affected (0.00 sec)
mysql> drop table if exists aa;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql>
mysql>
--查看表结构
mysql> desc liuyan;
+---------+------------------+------+-----+---------+----------------+
| Field   | Type             | Null | Key | Default | Extra          |
+---------+------------------+------+-----+---------+----------------+
| id      | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title   | varchar(32)      | NO   |     | NULL    |                |
| author  | varchar(32)      | NO   |     | wu      |                |
| addtime | datetime         | YES  |     | NULL    |                |
| content | text             | NO   |     | NULL    |                |
+---------+------------------+------+-----+---------+----------------+
5 rows in set (0.02 sec)
--采用标准方式添加一条数据
mysql> insert into liuyan(id,title,author,addtime,content)
    -> values(1,'news','zhangsan','2012-05-22 12:32:50','hello mysql');
Query OK, 1 row affected (0.01 sec)
--查看留言表中的所有数据。(*表示所有列)
mysql> select * from liuyan;
+----+-------+----------+---------------------+-------------+
| id | title | author   | addtime             | content     |
+----+-------+----------+---------------------+-------------+
|  1 | news  | zhangsan | 2012-05-22 12:32:50 | hello mysql |
+----+-------+----------+---------------------+-------------+
1 row in set (0.00 sec)
mysql> 
--添加数据(字段名的顺序可以颠倒)
mysql> insert into liuyan(id,content,addtime,title,author)
    -> values(2,'aaaaa','2012-12-24 12:12:12','info','lisi');
Query OK, 1 row affected (0.00 sec)
--只指定部分字段名来添加数据
mysql> insert into liuyan(title,addtime,content)
    -> values('test','2012-12-22','hello');
Query OK, 1 row affected (0.00 sec)
mysql> desc liuyan;
+---------+------------------+------+-----+---------+----------------+
| Field   | Type             | Null | Key | Default | Extra          |
+---------+------------------+------+-----+---------+----------------+
| id      | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title   | varchar(32)      | NO   |     | NULL    |                |
| author  | varchar(32)      | NO   |     | wu      |                |
| addtime | datetime         | YES  |     | NULL    |                |
| content | text             | NO   |     | NULL    |                |
+---------+------------------+------+-----+---------+----------------+
5 rows in set (0.00 sec)
--不指定字段名添加数据(values中要给所有字段赋值,并顺序一致)
mysql> insert into liuyan 
        -> values(null,'demo','wangwu','2012-09-10 12:34:56','ddddd');
Query OK, 1 row affected (0.00 sec)
mysql> select * from liuyan;
+----+-------+----------+---------------------+-------------+
| id | title | author   | addtime             | content     |
+----+-------+----------+---------------------+-------------+
|  1 | news  | zhangsan | 2012-05-22 12:32:50 | hello mysql |
|  2 | info  | lisi     | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test  | wu       | 2012-12-22 00:00:00 | hello       |
|  4 | demo  | wangwu   | 2012-09-10 12:34:56 | ddddd       |
+----+-------+----------+---------------------+-------------+
4 rows in set (0.00 sec)
mysql>
---批量添加3条数据
mysql> insert into liuyan
    -> values(null,'tt1','lisi1','2012-02-03 12:21:34','dddd'),
    -> (null,'tt2','lisi2','2012-02-03 12:21:34','eeee'),
    -> (null,'tt3','lisi3','2012-02-03 12:21:34','ffff');
Query OK, 3 rows affected (0.00 sec)
Records: 3  Duplicates: 0  Warnings: 0
mysql> select * from liuyan;
+----+-------+----------+---------------------+-------------+
| id | title | author   | addtime             | content     |
+----+-------+----------+---------------------+-------------+
|  1 | news  | zhangsan | 2012-05-22 12:32:50 | hello mysql |
|  2 | info  | lisi     | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test  | wu       | 2012-12-22 00:00:00 | hello       |
|  4 | demo  | wangwu   | 2012-09-10 12:34:56 | ddddd       |
|  5 | tt1   | lisi1    | 2012-02-03 12:21:34 | dddd        |
|  6 | tt2   | lisi2    | 2012-02-03 12:21:34 | eeee        |
|  7 | tt3   | lisi3    | 2012-02-03 12:21:34 | ffff        |
+----+-------+----------+---------------------+-------------+
7 rows in set (0.00 sec)
mysql>
mysql> create table demo(
    -> d1 tinyint not null,
    -> d2 int(4) zerofill not null,
    -> d3 double(4,2) not null,
    -> d4 varchar(4) not null);
Query OK, 0 rows affected (0.05 sec)
mysql> desc demo;
+-------+--------------------------+------+-----+---------+-------+
| Field | Type                     | Null | Key | Default | Extra |
+-------+--------------------------+------+-----+---------+-------+
| d1    | tinyint(4)               | NO   |     | NULL    |       |
| d2    | int(4) unsigned zerofill | NO   |     | NULL    |       |
| d3    | double(4,2)              | NO   |     | NULL    |       |
| d4    | varchar(4)               | NO   |     | NULL    |       |
+-------+--------------------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> show create table demo \G;
*************************** 1. row ***************************
       Table: demo
Create Table: CREATE TABLE `demo` (
  `d1` tinyint(4) NOT NULL,
  `d2` int(4) unsigned zerofill NOT NULL,
  `d3` double(4,2) NOT NULL,
  `d4` varchar(4) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
ERROR:
No query specified
mysql>mysql> desc demo;
+-------+--------------------------+------+-----+---------+-------+
| Field | Type                     | Null | Key | Default | Extra |
+-------+--------------------------+------+-----+---------+-------+
| d1    | tinyint(4)               | NO   |     | NULL    |       |
| d2    | int(4) unsigned zerofill | NO   |     | NULL    |       |
| d3    | double(4,2)              | NO   |     | NULL    |       |
| d4    | varchar(4)               | NO   |     | NULL    |       |
+-------+--------------------------+------+-----+---------+-------+
4 rows in set (0.00 sec)
mysql> insert into demo values(11,22,123.456,"abcdef");
Query OK, 1 row affected, 2 warnings (0.00 sec)
mysql> select * from demo;
+----+------+-------+------+
| d1 | d2   | d3    | d4   |
+----+------+-------+------+
| 11 | 0022 | 99.99 | abcd |
+----+------+-------+------+
1 row in set (0.00 sec)
mysql> insert into demo values(11,12345,12.3456,"abc");
Query OK, 1 row affected (0.00 sec)
mysql> select * from demo;
+----+-------+-------+------+
| d1 | d2    | d3    | d4   |
+----+-------+-------+------+
| 11 |  0022 | 99.99 | abcd |
| 11 | 12345 | 12.35 | abc  |
+----+-------+-------+------+
2 rows in set (0.00 sec)
mysql> insert into demo values(128,22,123.456,"abcdef");
Query OK, 1 row affected, 3 warnings (0.00 sec)
mysql> select * from demo;
+-----+-------+-------+------+
| d1  | d2    | d3    | d4   |
+-----+-------+-------+------+
|  11 |  0022 | 99.99 | abcd |
|  11 | 12345 | 12.35 | abc  |
| 127 |  0022 | 99.99 | abcd |
+-----+-------+-------+------+
3 rows in set (0.00 sec)
mysql>
================================================================
        表结构的修改
================================================================
--创建一个测试表格
mysql> create table news(
    -> title varchar(32) not null);
Query OK, 0 rows affected (0.08 sec)
--显示表结构
mysql> desc news;
+-------+-------------+------+-----+---------+-------+
| Field | Type        | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| title | varchar(32) | NO   |     | NULL    |       |
+-------+-------------+------+-----+---------+-------+
1 row in set (0.00 sec)
--为表添加一个主键列
mysql> alter table news add id int unsigned not null auto_increment primary key
first;
Query OK, 0 rows affected (0.09 sec)
Records: 0  Duplicates: 0  Warnings: 0
--显示表结构
mysql> desc news;
+-------+------------------+------+-----+---------+----------------+
| Field | Type             | Null | Key | Default | Extra          |
+-------+------------------+------+-----+---------+----------------+
| id    | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title | varchar(32)      | NO   |     | NULL    |                |
+-------+------------------+------+-----+---------+----------------+
2 rows in set (0.01 sec)
mysql> alter table news add content text not null;
Query OK, 0 rows affected (0.06 sec)
Records: 0  Duplicates: 0  Warnings: 0
--显示表结构
mysql> desc news;
+---------+------------------+------+-----+---------+----------------+
| Field   | Type             | Null | Key | Default | Extra          |
+---------+------------------+------+-----+---------+----------------+
| id      | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title   | varchar(32)      | NO   |     | NULL    |                |
| content | text             | NO   |     | NULL    |                |
+---------+------------------+------+-----+---------+----------------+
3 rows in set (0.02 sec)
--为表添加一个作者字段 varchar32位,在标题后面
mysql> alter table news add author varchar(32) not null after title;
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0
--显示表结构
mysql> desc news;
+---------+------------------+------+-----+---------+----------------+
| Field   | Type             | Null | Key | Default | Extra          |
+---------+------------------+------+-----+---------+----------------+
| id      | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title   | varchar(32)      | NO   |     | NULL    |                |
| author  | varchar(32)      | NO   |     | NULL    |                |
| content | text             | NO   |     | NULL    |                |
+---------+------------------+------+-----+---------+----------------+
4 rows in set (0.02 sec)
--将字段author修改为username类型varchar(16)
mysql> alter table news change author username varchar(16) not null;
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0
--显示表结构
mysql> desc news;
+----------+------------------+------+-----+---------+----------------+
| Field    | Type             | Null | Key | Default | Extra          |
+----------+------------------+------+-----+---------+----------------+
| id       | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title    | varchar(32)      | NO   |     | NULL    |                |
| username | varchar(16)      | NO   |     | NULL    |                |
| content  | text             | NO   |     | NULL    |                |
+----------+------------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)
--删除一个字段
mysql> alter table news drop content;
Query OK, 0 rows affected (0.08 sec)
Records: 0  Duplicates: 0  Warnings: 0
--显示表结构
mysql> desc news;
+----------+------------------+------+-----+---------+----------------+
| Field    | Type             | Null | Key | Default | Extra          |
+----------+------------------+------+-----+---------+----------------+
| id       | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| title    | varchar(32)      | NO   |     | NULL    |                |
| username | varchar(16)      | NO   |     | NULL    |                |
+----------+------------------+------+-----+---------+----------------+
3 rows in set (0.01 sec)
mysql>
================================================================
        修改表数据
================================================================
mysql>
mysql> select * from liuyan;
+----+-------+----------+---------------------+-------------+
| id | title | author   | addtime             | content     |
+----+-------+----------+---------------------+-------------+
|  1 | news  | zhangsan | 2012-05-22 12:32:50 | hello mysql |
|  2 | info  | lisi     | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test  | wu       | 2012-12-22 00:00:00 | hello       |
|  4 | demo  | wangwu   | 2012-09-10 12:34:56 | ddddd       |
|  5 | tt1   | lisi1    | 2012-02-03 12:21:34 | dddd        |
|  6 | tt2   | lisi2    | 2012-02-03 12:21:34 | eeee        |
|  7 | tt3   | lisi3    | 2012-02-03 12:21:34 | ffff        |
+----+-------+----------+---------------------+-------------+
7 rows in set (0.00 sec)
--修改留言表中author字段值为qq(所有数据)
mysql> update liuyan set author='qq';
Query OK, 7 rows affected (0.00 sec)
Rows matched: 7  Changed: 7  Warnings: 0
mysql> select * from liuyan;
+----+-------+--------+---------------------+-------------+
| id | title | author | addtime             | content     |
+----+-------+--------+---------------------+-------------+
|  1 | news  | qq     | 2012-05-22 12:32:50 | hello mysql |
|  2 | info  | qq     | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test  | qq     | 2012-12-22 00:00:00 | hello       |
|  4 | demo  | qq     | 2012-09-10 12:34:56 | ddddd       |
|  5 | tt1   | qq     | 2012-02-03 12:21:34 | dddd        |
|  6 | tt2   | qq     | 2012-02-03 12:21:34 | eeee        |
|  7 | tt3   | qq     | 2012-02-03 12:21:34 | ffff        |
+----+-------+--------+---------------------+-------------+
7 rows in set (0.00 sec)
--修改留言表中某列的某几条数据。
mysql> update liuyan set author='zhangsan' where  id in(1,3,5);
Query OK, 3 rows affected (0.03 sec)
Rows matched: 3  Changed: 3  Warnings: 0
mysql> select * from liuyan;
+----+-------+----------+---------------------+-------------+
| id | title | author   | addtime             | content     |
+----+-------+----------+---------------------+-------------+
|  1 | news  | zhangsan | 2012-05-22 12:32:50 | hello mysql |
|  2 | info  | qq       | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test  | zhangsan | 2012-12-22 00:00:00 | hello       |
|  4 | demo  | qq       | 2012-09-10 12:34:56 | ddddd       |
|  5 | tt1   | zhangsan | 2012-02-03 12:21:34 | dddd        |
|  6 | tt2   | qq       | 2012-02-03 12:21:34 | eeee        |
|  7 | tt3   | qq       | 2012-02-03 12:21:34 | ffff        |
+----+-------+----------+---------------------+-------------+
7 rows in set (0.00 sec)
--修改某条数据的某几列。
mysql> update liuyan set title='llllll',author="lisi",content="qwertyuio"
    -> where id=7;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0
mysql> select * from liuyan;
+----+--------+----------+---------------------+-------------+
| id | title  | author   | addtime             | content     |
+----+--------+----------+---------------------+-------------+
|  1 | news   | zhangsan | 2012-05-22 12:32:50 | hello mysql |
|  2 | info   | qq       | 2012-12-24 12:12:12 | aaaaa       |
|  3 | test   | zhangsan | 2012-12-22 00:00:00 | hello       |
|  4 | demo   | qq       | 2012-09-10 12:34:56 | ddddd       |
|  5 | tt1    | zhangsan | 2012-02-03 12:21:34 | dddd        |
|  6 | tt2    | qq       | 2012-02-03 12:21:34 | eeee        |
|  7 | llllll | lisi     | 2012-02-03 12:21:34 | qwertyuio   |
+----+--------+----------+---------------------+-------------+
7 rows in set (0.00 sec)
--将6号信息中的作者改为王五
mysql>update liuyan set author="wangwu" where id=6;
mysql> select * from demo;
+-----+-------+-------+------+
| d1  | d2    | d3    | d4   |
+-----+-------+-------+------+
|  11 |  0022 | 99.99 | abcd |
|  11 | 12345 | 12.35 | abc  |
| 127 |  0022 | 99.99 | abcd |
+-----+-------+-------+------+
3 rows in set (0.00 sec)
--将demo表中d1字段的所有值都减一。
mysql> update demo set d1=d1-1;
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0
mysql> select * from demo;
+-----+-------+-------+------+
| d1  | d2    | d3    | d4   |
+-----+-------+-------+------+
|  10 |  0022 | 99.99 | abcd |
|  10 | 12345 | 12.35 | abc  |
| 126 |  0022 | 99.99 | abcd |
+-----+-------+-------+------+
3 rows in set (0.00 sec)
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