记录MySQL的一些基础操作

MySQL建表操作

root@localhost 08:05:22> create table stu(

    -> id int(4) not null,

    -> name char(20) not null,

    -> age tinyint(2) not null default '0',

    -> dept varchar(16) default null

    -> );

Query OK, 0 rows affected (0.01 sec)

root@localhost 08:07:20>

root@localhost 08:07:21> show tables;

+----------------+

| Tables_in_test |

+----------------+

| stu            |

+----------------+

1 row in set (0.00 sec)

root@localhost 08:07:25> desc stu;

+-------+-------------+------+-----+---------+-------+

| Field | Type        | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id    | int(4)      | NO   |     | NULL    |       |

| name  | char(20)    | NO   |     | NULL    |       |

| age   | tinyint(2)  | NO   |     | 0       |       |

| dept  | varchar(16) | YES  |     | NULL    |       |

+-------+-------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

root@localhost 08:07:28>

root@localhost 08:07:28> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(4) NOT NULL,

  `name` char(20) NOT NULL,

  `age` tinyint(2) NOT NULL DEFAULT '0',

  `dept` varchar(16) DEFAULT NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

root@localhost 08:08:47>

mysql5.1及以前的默认引擎是MyISAM，MySQL5.5及以后的默认引擎的InnoDB

int 整数类型

char 定长字符串类型，存储时总是用空格填满右边到指定的长度

varchar 变长字符串类型

其他详细信息可以参考 MySQL手册

为表的字段添加索引

索引类似于书的目录，如果在字段上建立索引，那么以索引列为查询条件就可以加快查询数据的速度

root@localhost 08:38:25> create table student(

    -> id int(4) not null AUTO_INCREMENT,

    -> name char(20) not null,

    -> age tinyint(2) NOT NULL default '0',

    -> dept varchar(16) default NULL,

    -> primary key(id),

    -> KEY index_name (name)

    -> );

Query OK, 0 rows affected (0.00 sec)

root@localhost 08:38:31>

root@localhost 08:40:02> desc student;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(4)      | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   | MUL | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 08:40:16> show create table student\G

*************************** 1. row ***************************

       Table: student

Create Table: CREATE TABLE `student` (

  `id` int(4) NOT NULL AUTO_INCREMENT,

  `name` char(20) NOT NULL,

  `age` tinyint(2) NOT NULL DEFAULT '0',

  `dept` varchar(16) DEFAULT NULL,

  PRIMARY KEY (`id`),

  KEY `index_name` (`name`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

root@localhost 08:40:18>

alter table 修改表结构

1.alter 增加主键索引

root@localhost 08:50:04> create table stu(

    -> id int(4) not null,

    -> name char(20) not null,

    -> age tinyint(2) NOT NULL default '0',

    -> dept varchar(16) default NULL,

    -> KEY index_name (name)

    -> );

Query OK, 0 rows affected (0.01 sec)

root@localhost 08:50:05> show tables;

+----------------+

| Tables_in_test |

+----------------+

| stu            |

| student        |

+----------------+

2 rows in set (0.00 sec)

root@localhost 08:50:12> desc stu;

+-------+-------------+------+-----+---------+-------+

| Field | Type        | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id    | int(4)      | NO   |     | NULL    |       |

| name  | char(20)    | NO   | MUL | NULL    |       |

| age   | tinyint(2)  | NO   |     | 0       |       |

| dept  | varchar(16) | YES  |     | NULL    |       |

+-------+-------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

root@localhost 08:50:15> alter table stu change id id int primary key auto_increment;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 08:51:16> desc stu;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   | MUL | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 08:51:19>

2.alter删除主键索引（然后再添加主键索引）

root@localhost 08:53:30> create table stu1(

    -> id int(4) not null,

    -> name char(20) not null,

    -> age tinyint(2) NOT NULL default '0',

    -> dept varchar(16) default NULL,

    -> primary key(id),

    -> KEY index_name (name)

    -> );

Query OK, 0 rows affected (0.01 sec)

root@localhost 08:53:54> desc stu1;

+-------+-------------+------+-----+---------+-------+

| Field | Type        | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id    | int(4)      | NO   | PRI | NULL    |       |

| name  | char(20)    | NO   | MUL | NULL    |       |

| age   | tinyint(2)  | NO   |     | 0       |       |

| dept  | varchar(16) | YES  |     | NULL    |       |

+-------+-------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

root@localhost 08:54:20> alter table stu1 drop primary key;

Query OK, 0 rows affected (0.00 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 08:54:27> desc stu1;

+-------+-------------+------+-----+---------+-------+

| Field | Type        | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id    | int(4)      | NO   |     | NULL    |       |

| name  | char(20)    | NO   | MUL | NULL    |       |

| age   | tinyint(2)  | NO   |     | 0       |       |

| dept  | varchar(16) | YES  |     | NULL    |       |

+-------+-------------+------+-----+---------+-------+

4 rows in set (0.01 sec)

root@localhost 08:54:30>

root@localhost 08:57:08> desc stu1;

+-------+-------------+------+-----+---------+-------+

| Field | Type        | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id    | int(4)      | NO   |     | NULL    |       |

| name  | char(20)    | NO   | MUL | NULL    |       |

| age   | tinyint(2)  | NO   |     | 0       |       |

| dept  | varchar(16) | YES  |     | NULL    |       |

+-------+-------------+------+-----+---------+-------+

4 rows in set (0.00 sec)

root@localhost 08:57:10> alter table stu1 change id id int primary key auto_increment;

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 08:57:32> desc stu1;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   | MUL | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 08:57:34>

3.alter删除普通索引以及添加普通索引

root@localhost 09:06:31> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(20) NOT NULL,

  `age` tinyint(2) NOT NULL DEFAULT '0',

  `dept` varchar(16) DEFAULT NULL,

  PRIMARY KEY (`id`),

  KEY `index_name` (`name`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

root@localhost 09:07:07> desc stu;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   | MUL | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:07:15> alter table stu drop index index_name;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:07:29> desc stu;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   |     | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:07:31>

root@localhost 09:07:59> alter table stu add index index_dept(dept);

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:08:21> desc stu;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | char(20)    | NO   |     | NULL    |                |

| age   | tinyint(2)  | NO   |     | 0       |                |

| dept  | varchar(16) | YES  | MUL | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:08:23>

4.alter 修改字段

root@localhost 09:08:23> alter table stu change dept dept varchar(200) not null default "TP";

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:10:25> desc stu;

+-------+--------------+------+-----+---------+----------------+

| Field | Type         | Null | Key | Default | Extra          |

+-------+--------------+------+-----+---------+----------------+

| id    | int(11)      | NO   | PRI | NULL    | auto_increment |

| name  | char(20)     | NO   |     | NULL    |                |

| age   | tinyint(2)   | NO   |     | 0       |                |

| dept  | varchar(200) | NO   | MUL | TP      |                |

+-------+--------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:10:28>

root@localhost 09:10:28> alter table stu add index index_name(name);

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:11:38> desc stu;

+-------+--------------+------+-----+---------+----------------+

| Field | Type         | Null | Key | Default | Extra          |

+-------+--------------+------+-----+---------+----------------+

| id    | int(11)      | NO   | PRI | NULL    | auto_increment |

| name  | char(20)     | NO   | MUL | NULL    |                |

| age   | tinyint(2)   | NO   |     | 0       |                |

| dept  | varchar(200) | NO   | MUL | TP      |                |

+-------+--------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:11:39> alter table stu change name name char(50) not null default "Simon";

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:12:23> desc stu;

+-------+--------------+------+-----+---------+----------------+

| Field | Type         | Null | Key | Default | Extra          |

+-------+--------------+------+-----+---------+----------------+

| id    | int(11)      | NO   | PRI | NULL    | auto_increment |

| name  | char(50)     | NO   | MUL | Simon   |                |

| age   | tinyint(2)   | NO   |     | 0       |                |

| dept  | varchar(200) | NO   | MUL | TP      |                |

+-------+--------------+------+-----+---------+----------------+

4 rows in set (0.00 sec)

root@localhost 09:12:24>

root@localhost 10:13:26> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| dept        | varchar(200) | NO   | MUL | TP         |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 10:13:30>

root@localhost 10:20:21> alter table stu change dept department varchar(200) NOT NULL DEFAULT 'TP_cloud' COMMENT '谷歌部门信息';

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 10:20:24>

root@localhost 10:20:33> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 10:20:42>

5.alter 添加列

root@localhost 09:19:41> alter table stu add column description longtext;

Query OK, 0 rows affected (0.00 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:21:58> desc stu;

+-------------+--------------+------+-----+---------+----------------+

| Field       | Type         | Null | Key | Default | Extra          |

+-------------+--------------+------+-----+---------+----------------+

| id          | int(11)      | NO   | PRI | NULL    | auto_increment |

| name        | char(50)     | NO   | MUL | Simon   |                |

| age         | tinyint(2)   | NO   |     | 0       |                |

| dept        | varchar(200) | NO   | MUL | TP      |                |

| description | longtext     | YES  |     | NULL    |                |

+-------------+--------------+------+-----+---------+----------------+

5 rows in set (0.00 sec)

root@localhost 09:22:00> alter table stu add column date datetime;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:22:54> desc stu;

+-------------+--------------+------+-----+---------+----------------+

| Field       | Type         | Null | Key | Default | Extra          |

+-------------+--------------+------+-----+---------+----------------+

| id          | int(11)      | NO   | PRI | NULL    | auto_increment |

| name        | char(50)     | NO   | MUL | Simon   |                |

| age         | tinyint(2)   | NO   |     | 0       |                |

| dept        | varchar(200) | NO   | MUL | TP      |                |

| description | longtext     | YES  |     | NULL    |                |

| date        | datetime     | YES  |     | NULL    |                |

+-------------+--------------+------+-----+---------+----------------+

6 rows in set (0.01 sec)

root@localhost 09:24:54> alter table stu change date date datetime not null comment '插入时间';

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:24:58>

root@localhost 09:24:58> desc stu;

+-------------+--------------+------+-----+---------+----------------+

| Field       | Type         | Null | Key | Default | Extra          |

+-------------+--------------+------+-----+---------+----------------+

| id          | int(11)      | NO   | PRI | NULL    | auto_increment |

| name        | char(50)     | NO   | MUL | Simon   |                |

| age         | tinyint(2)   | NO   |     | 0       |                |

| dept        | varchar(200) | NO   | MUL | TP      |                |

| description | longtext     | YES  |     | NULL    |                |

| date        | datetime     | NO   |     | NULL    |                |

+-------------+--------------+------+-----+---------+----------------+

6 rows in set (0.00 sec)

root@localhost 09:27:22>

6.查看表字段的注释

root@localhost 09:35:21> select column_name,column_comment from information_schema.columns where table_name='stu' and table_schema='test';

+-------------+----------------+

| column_name | column_comment |

+-------------+----------------+

| id          |                |

| name        |                |

| age         |                |

| dept        |                |

| description |                |

| date        | 插入时间   |

+-------------+----------------+

6 rows in set (0.00 sec)

root@localhost 09:35:26> 

show full columns from stu\G   也可以

7.添加注释

给表添加注释

ALTER TABLE table_name COMMENT='这是表的注释';

给字段添加注释

alter table stu change column name name char(50) not null default 'Simon Paul' comment '学生姓名字段注释';

8.对字段前n个字符创建索引

root@localhost 09:50:53> create index index_desc on stu(description(66));

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:52:17> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | MUL | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| dept        | varchar(200) | NO   | MUL | TP         |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 09:52:24> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(50) NOT NULL DEFAULT 'Simon Paul' COMMENT '学生姓名字段注释',

  `age` tinyint(2) NOT NULL DEFAULT '23' COMMENT '年龄',

  `dept` varchar(200) NOT NULL DEFAULT 'TP' COMMENT '单位信息',

  `description` longtext NOT NULL COMMENT '这个是学生描述信息字段的注释',

  `date` datetime NOT NULL COMMENT '插入时间',

  PRIMARY KEY (`id`),

  KEY `index_dept` (`dept`),

  KEY `index_name` (`name`),

  KEY `index_desc` (`description`(66))

) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='这是stu表的注释'

1 row in set (0.00 sec)

root@localhost 09:52:28>

9.更该索引

MySQL并没有提供修改索引的直接指令，一般情况下，我们需要先删除掉原索引，再根据需要创建一个同名的索引，从而变相地实现修改索引操作

show index from stu\G

root@localhost 09:52:24> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(50) NOT NULL DEFAULT 'Simon Paul' COMMENT '学生姓名字段注释',

  `age` tinyint(2) NOT NULL DEFAULT '23' COMMENT '年龄',

  `dept` varchar(200) NOT NULL DEFAULT 'TP' COMMENT '单位信息',

  `description` longtext NOT NULL COMMENT '这个是学生描述信息字段的注释',

  `date` datetime NOT NULL COMMENT '插入时间',

  PRIMARY KEY (`id`),

  KEY `index_dept` (`dept`),

  KEY `index_name` (`name`),

  KEY `index_desc` (`description`(66))

) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='这是stu表的注释'

1 row in set (0.00 sec)

root@localhost 09:52:28> alter table stu drop index index_name;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:56:30> create index index_name on stu(name(12));

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 09:56:56> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(50) NOT NULL DEFAULT 'Simon Paul' COMMENT '学生姓名字段注释',

  `age` tinyint(2) NOT NULL DEFAULT '23' COMMENT '年龄',

  `dept` varchar(200) NOT NULL DEFAULT 'TP' COMMENT '单位信息',

  `description` longtext NOT NULL COMMENT '这个是学生描述信息字段的注释',

  `date` datetime NOT NULL COMMENT '插入时间',

  PRIMARY KEY (`id`),

  KEY `index_dept` (`dept`),

  KEY `index_desc` (`description`(66)),

  KEY `index_name` (`name`(12))

) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='这是stu表的注释'

1 row in set (0.00 sec)

root@localhost 09:57:04>

10.为表的多个字段创建联合索引

create index index_name_dept on stu(name(8),dept);

11.删除索引

drop index index_name on stu;

12.创唯一索引（非主键）

create unique index uniq_index_name on stu(name);

Finnaly

root@localhost 10:25:54> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 10:25:58> show create table stu\G

*************************** 1. row ***************************

       Table: stu

Create Table: CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(50) NOT NULL DEFAULT 'Simon Paul' COMMENT '学生姓名字段注释',

  `age` tinyint(2) NOT NULL DEFAULT '23' COMMENT '年龄',

  `department` varchar(200) NOT NULL DEFAULT 'TP_cloud' COMMENT '谷歌部门信息',

  `description` longtext NOT NULL COMMENT '这个是学生描述信息字段的注释',

  `date` datetime NOT NULL COMMENT '插入时间',

  PRIMARY KEY (`id`),

  UNIQUE KEY `uniq_index_name` (`name`),

  KEY `index_dept` (`department`),

  KEY `index_desc` (`description`(66)),

  KEY `index_name_dept` (`name`(8),`department`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1 COMMENT='这是stu表的注释'

1 row in set (0.00 sec)

root@localhost 10:26:09>

alter添加字段到指定的位置

root@localhost 10:28:00> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 10:28:08> alter table stu add column sex tinyint(1) not null after description;

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 10:29:19> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| sex         | tinyint(1)   | NO   |     | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

7 rows in set (0.00 sec)

root@localhost 10:29:21>

root@localhost 10:29:57> alter table stu change column sex sex tinyint(1) not null default 1 after description;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 10:30:47> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| sex         | tinyint(1)   | NO   |     | 1          |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

7 rows in set (0.00 sec)

root@localhost 10:30:53>

root@localhost 10:30:53> alter table stu drop column sex;

Query OK, 0 rows affected (0.01 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 10:33:39> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

6 rows in set (0.00 sec)

root@localhost 10:33:45>

root@localhost 10:33:45> alter table stu add column sex tinyint(1) not null default 1 before date;

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'before date' at line 1

root@localhost 10:34:24> alter table stu add column sex tinyint(1) not null default 1 first;

Query OK, 0 rows affected (0.02 sec)

Records: 0  Duplicates: 0  Warnings: 0

root@localhost 10:36:49> desc stu;

+-------------+--------------+------+-----+------------+----------------+

| Field       | Type         | Null | Key | Default    | Extra          |

+-------------+--------------+------+-----+------------+----------------+

| sex         | tinyint(1)   | NO   |     | 1          |                |

| id          | int(11)      | NO   | PRI | NULL       | auto_increment |

| name        | char(50)     | NO   | UNI | Simon Paul |                |

| age         | tinyint(2)   | NO   |     | 23         |                |

| department  | varchar(200) | NO   | MUL | TP_cloud   |                |

| description | longtext     | NO   | MUL | NULL       |                |

| date        | datetime     | NO   |     | NULL       |                |

+-------------+--------------+------+-----+------------+----------------+

7 rows in set (0.00 sec)

root@localhost 10:36:51>

# 多查看帮助文档

help alter table

INSERT 和 UPDATE

root@localhost 10:44:46> insert into stu(name,age,department,description,date) values('Tim',39,'Tencent','Connecting people for a greater future.',now());

Query OK, 1 row affected (0.00 sec)

root@localhost 10:46:37>

root@localhost 10:46:40> update stu set description='Just stick to what you love and belive in.' where name='Mark';

Query OK, 1 row affected (0.00 sec)

Rows matched: 1  Changed: 1  Warnings: 0

root@localhost 11:02:41> select * from stu;

+----+------------------+-----+-------------+--------------------------------------------------+---------------------+

| id | name             | age | department  | description                                      | date                |

+----+------------------+-----+-------------+--------------------------------------------------+---------------------+

|  1 | standby          |  23 | live_cloud  | Use ATS to archive the multiple level's cache.   | 0000-00-00 00:00:00 |

|  2 | Jefrriy          |  25 | live_cloud  | Use Squid to archive the multiple level's cache. | 0000-00-00 00:00:00 |

|  3 | Mark             |  47 | Mindjet     | Just stick to what you love and belive in.       | 2017-03-12 10:43:56 |

|  4 | Frankyang        |  35 | Google      | DNS administrator                                | 2017-03-12 10:44:46 |

|  5 | Tim              |  39 | Tencent     | Connecting people for a greater future.          | 2017-03-12 10:46:37 |

|  6 | Michael Widenius |  43 | MariaDB inc | The Fastest Growing Open Source Database.        | 2017-03-12 10:56:31 |

+----+------------------+-----+-------------+--------------------------------------------------+---------------------+

6 rows in set (0.00 sec)

root@localhost 11:02:47>

MYSQLDUMP

[root@standby ~]# mysqldump -uroot -p123456 -B test >/tmp/test_bak_20170312.sql

[root@standby ~]# ll /tmp/

total 8

-rw-r--r-- 1 root root 3236 Mar 12 11:01 test_bak_20170312.sql

drwx------ 2 root root 4096 Sep 17 22:51 tmux-0

[root@standby ~]#

[root@standby ~]# cat /tmp/test_bak_20170312.sql

-- MySQL dump 10.13  Distrib 5.1.72, for unknown-linux-gnu (x86_64)

--

-- Host: localhost    Database: test

-- ------------------------------------------------------

-- Server version	5.1.72

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;

/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;

/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;

/*!40101 SET NAMES utf8 */;

/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;

/*!40103 SET TIME_ZONE='+00:00' */;

/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;

/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;

/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;

/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--

-- Current Database: `test`

--

CREATE DATABASE /*!32312 IF NOT EXISTS*/ `test` /*!40100 DEFAULT CHARACTER SET latin1 */;

USE `test`;

--

-- Table structure for table `stu`

--

DROP TABLE IF EXISTS `stu`;

/*!40101 SET @saved_cs_client     = @@character_set_client */;

/*!40101 SET character_set_client = utf8 */;

CREATE TABLE `stu` (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` char(50) NOT NULL DEFAULT 'Simon Paul' COMMENT 'å¦ç”Ÿå§“åå—æ®µæ³¨é‡Š',

  `age` tinyint(2) NOT NULL DEFAULT '23' COMMENT 'å¹´é¾„',

  `department` varchar(200) NOT NULL DEFAULT 'TP_cloud' COMMENT 'çˆ±å¥‡è‰ºéƒ¨é—¨ä¿¡æ¯',

  `description` longtext NOT NULL COMMENT 'è¿™ä¸ªæ˜¯å¦ç”Ÿæè¿°ä¿¡æ¯å—æ®µçš„æ³¨é‡Š',

  `date` datetime NOT NULL COMMENT 'æ’å…¥æ—¶é—´',

  PRIMARY KEY (`id`),

  UNIQUE KEY `uniq_index_name` (`name`),

  KEY `index_dept` (`department`),

  KEY `index_desc` (`description`(66)),

  KEY `index_name_dept` (`name`(8),`department`)

) ENGINE=MyISAM AUTO_INCREMENT=7 DEFAULT CHARSET=latin1 COMMENT='è¿™æ˜¯stuè¡¨çš„æ³¨é‡Š';

/*!40101 SET character_set_client = @saved_cs_client */;

--

-- Dumping data for table `stu`

--

LOCK TABLES `stu` WRITE;

/*!40000 ALTER TABLE `stu` DISABLE KEYS */;

INSERT INTO `stu` VALUES (1,'standby',23,'live_cloud','Use ATS to archive the multiple level\'s cache.','0000-00-00 00:00:00'),(2,'Jefrriy',25,'live_cloud','Use Squid to archive the multiple level\'s cache.','0000-00-00 00:00:00'),(3,'Mark',47,'Mindjet','Just stick to what you love and belive in.','2017-03-12 10:43:56'),(4,'Frankyang',35,'Google','DNS administrator','2017-03-12 10:44:46'),(5,'Tim',39,'Tencent','Connecting people for a greater future.','2017-03-12 10:46:37'),(6,'Michael Widenius',43,'MariaDB inc','The Fastest Growing Open Source Database.','2017-03-12 10:56:31');

/*!40000 ALTER TABLE `stu` ENABLE KEYS */;

UNLOCK TABLES;

/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;

/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;

/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;

/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;

/*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */;

/*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */;

/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

-- Dump completed on 2017-03-12 11:01:59

[root@standby ~]#

降序/升序/limit

mysql> select user,host,password from mysql.user;

+------+-----------+-------------------------------------------+

| user | host      | password                                  |

+------+-----------+-------------------------------------------+

| root | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

+------+-----------+-------------------------------------------+

2 rows in set (0.00 sec)

mysql> select user,host,password from mysql.user order by user asc;

+------+-----------+-------------------------------------------+

| user | host      | password                                  |

+------+-----------+-------------------------------------------+

| root | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

+------+-----------+-------------------------------------------+

2 rows in set (0.00 sec)

mysql> select user,host,password from mysql.user order by user desc;

+------+-----------+-------------------------------------------+

| user | host      | password                                  |

+------+-----------+-------------------------------------------+

| wiki | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

| root | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

+------+-----------+-------------------------------------------+

2 rows in set (0.00 sec)

mysql> select user,host,password from mysql.user order by user desc limit 1;

+------+-----------+-------------------------------------------+

| user | host      | password                                  |

+------+-----------+-------------------------------------------+

| wiki | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

+------+-----------+-------------------------------------------+

1 row in set (0.00 sec)

mysql>

like 模糊匹配

root@localhost 10:30:14> show databases;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| No_wiki            |

| iQiYi              |

| mysql              |

| wiki               |

| wiki001            |

| wiki002            |

| wiki003            |

+--------------------+

8 rows in set (0.00 sec)

root@localhost 10:30:20> show databases like 'wiki%';

+------------------+

| Database (wiki%) |

+------------------+

| wiki             |

| wiki001          |

| wiki002          |

| wiki003          |

+------------------+

4 rows in set (0.00 sec)

root@localhost 10:30:25>

常用函数

root@localhost 10:34:46> select database();

+------------+

| database() |

+------------+

| wiki       |

+------------+

1 row in set (0.00 sec)

root@localhost 10:34:52> select user();

+----------------+

| user()         |

+----------------+

| root@localhost |

+----------------+

1 row in set (0.00 sec)

root@localhost 10:34:56> select now();

+---------------------+

| now()               |

+---------------------+

| 2017-03-11 22:35:00 |

+---------------------+

1 row in set (0.01 sec)

root@localhost 10:35:00> select version();

+-----------+

| version() |

+-----------+

| 5.1.72    |

+-----------+

1 row in set (0.00 sec)

root@localhost 10:35:05>

创建新用户并授权

只使用 `grant` 创建用户并授权

root@localhost 10:43:48> grant all privileges on iQiYi.* to 'standby'@'localhost' identified by 'liulixin';

Query OK, 0 rows affected (0.01 sec)

root@localhost 10:44:26> select user,host,password from user;

+---------+-----------+-------------------------------------------+

| user    | host      | password                                  |

+---------+-----------+-------------------------------------------+

| root    | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki    | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

| standby | localhost | *68400CF212112D85B99EB397ADCB27748218BFAE |

+---------+-----------+-------------------------------------------+

3 rows in set (0.00 sec)

root@localhost 10:44:31> 

root@localhost 10:44:58> select user,host,password from user where user like '%and%';

+---------+-----------+-------------------------------------------+

| user    | host      | password                                  |

+---------+-----------+-------------------------------------------+

| standby | localhost | *68400CF212112D85B99EB397ADCB27748218BFAE |

+---------+-----------+-------------------------------------------+

1 row in set (0.00 sec)

root@localhost 10:45:12>

grant all privileges on iQiYi.* to 'standby'@'localhost' identified by 'liulixin';

使用 `create` 和 `grant` 创建用户并授权

root@localhost 10:56:11> CREATE USER 'standby001'@'localhost' IDENTIFIED BY '123456';

Query OK, 0 rows affected (0.00 sec)

root@localhost 10:56:38> GRANT ALL ON No_wiki.* TO 'standby001'@'localhost';

Query OK, 0 rows affected (0.00 sec)

root@localhost 10:57:22>

root@localhost 10:57:26> select user,host,password from mysql.user;

+------------+-----------+-------------------------------------------+

| user       | host      | password                                  |

+------------+-----------+-------------------------------------------+

| root       | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki       | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

| standby    | localhost | *68400CF212112D85B99EB397ADCB27748218BFAE |

| standby001 | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

+------------+-----------+-------------------------------------------+

4 rows in set (0.00 sec)

root@localhost 10:57:41> show grants for 'standby001'@'localhost';

+-------------------------------------------------------------------------------------------------------------------+

| Grants for standby001@localhost                                                                                   |

+-------------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'standby001'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |

| GRANT ALL PRIVILEGES ON `No_wiki`.* TO 'standby001'@'localhost'                                                   |

+-------------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

root@localhost 10:58:03> show grants for 'standby001'@'localhost'\G

*************************** 1. row ***************************

Grants for standby001@localhost: GRANT USAGE ON *.* TO 'standby001'@'localhost' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9'

*************************** 2. row ***************************

Grants for standby001@localhost: GRANT ALL PRIVILEGES ON `No_wiki`.* TO 'standby001'@'localhost'

2 rows in set (0.00 sec)

root@localhost 10:58:06>

查看某个用户的授权情况

root@localhost 10:48:54> show grants for 'standby'@'localhost';

+----------------------------------------------------------------------------------------------------------------+

| Grants for standby@localhost                                                                                   |

+----------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'standby'@'localhost' IDENTIFIED BY PASSWORD '*68400CF212112D85B99EB397ADCB27748218BFAE' |

| GRANT ALL PRIVILEGES ON `iQiYi`.* TO 'standby'@'localhost'                                                     |

+----------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

root@localhost 10:49:10> show grants for 'standby'@'localhost'\G

*************************** 1. row ***************************

Grants for standby@localhost: GRANT USAGE ON *.* TO 'standby'@'localhost' IDENTIFIED BY PASSWORD '*68400CF212112D85B99EB397ADCB27748218BFAE'

*************************** 2. row ***************************

Grants for standby@localhost: GRANT ALL PRIVILEGES ON `iQiYi`.* TO 'standby'@'localhost'

2 rows in set (0.00 sec)

root@localhost 10:49:14>

授权局域网内主机远程连接数据库

root@localhost 11:07:07> grant all privileges on wiki.* to 'remote_test'@'10.0.0.%' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:08:40> flush privileges;

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:08:46> select user,host,password from mysql.user;

+-------------+-----------+-------------------------------------------+

| user        | host      | password                                  |

+-------------+-----------+-------------------------------------------+

| root        | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki        | localhost | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

| standby     | localhost | *68400CF212112D85B99EB397ADCB27748218BFAE |

| standby001  | localhost | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| remote_test | 10.0.0.%  | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

+-------------+-----------+-------------------------------------------+

5 rows in set (0.00 sec)

root@localhost 11:08:48> 

root@localhost 11:08:48> grant all privileges on wiki.* to 'remote_test001'@'10.0.0.0/24' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:10:39> grant all privileges on wiki.* to 'remote_test002'@'10.0.0.0/255.255.255.0' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:11:19> flush privileges;

Query OK, 0 rows affected (0.01 sec)

root@localhost 11:11:20> select user,host,password from mysql.user;

+----------------+------------------------+-------------------------------------------+

| user           | host                   | password                                  |

+----------------+------------------------+-------------------------------------------+

| root           | localhost              | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| wiki           | localhost              | *A5DB2D927D6DF94DA5E1CE4B293AEAAB4D8304EA |

| standby        | localhost              | *68400CF212112D85B99EB397ADCB27748218BFAE |

| standby001     | localhost              | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| remote_test    | 10.0.0.%               | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| remote_test001 | 10.0.0.0/24            | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

| remote_test002 | 10.0.0.0/255.255.255.0 | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |

+----------------+------------------------+-------------------------------------------+

7 rows in set (0.00 sec)

root@localhost 11:11:49>

grant all privileges on wiki.* to 'remote_test'@'10.0.0.%' identified by '123456'; 可用
grant all privileges on wiki.* to 'remote_test002'@'10.0.0.0/255.255.255.0' identified by '123456'; 可用
grant all privileges on wiki.* to 'remote_test001'@'10.0.0.0/24' identified by '123456'; 不可用

远端连接的命令：

mysql -u remote_test -h 10.0.0.9 -p123456

-P 指定端口

INVOKE收回某个授权/反向查看ALL PRIVILEGES都有哪些具体权限

root@localhost 11:24:12> show grants for 'standby'@'localhost';

+----------------------------------------------------------------------------------------------------------------+

| Grants for standby@localhost                                                                                   |

+----------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'standby'@'localhost' IDENTIFIED BY PASSWORD '*68400CF212112D85B99EB397ADCB27748218BFAE' |

| GRANT ALL PRIVILEGES ON `iQiYi`.* TO 'standby'@'localhost'                                                     |

+----------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

root@localhost 11:24:16> REVOKE INSERT ON `iQiYi`.* FROM 'standby'@'localhost';

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:28:27> show grants for 'standby'@'localhost';

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Grants for standby@localhost                                                                                                                                                                                                     |

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'standby'@'localhost' IDENTIFIED BY PASSWORD '*68400CF212112D85B99EB397ADCB27748218BFAE'                                                                                                                   |

| GRANT SELECT, UPDATE, DELETE, CREATE, DROP, REFERENCES, INDEX, ALTER, CREATE TEMPORARY TABLES, LOCK TABLES, EXECUTE, CREATE VIEW, SHOW VIEW, CREATE ROUTINE, ALTER ROUTINE, EVENT, TRIGGER ON `iQiYi`.* TO 'standby'@'localhost' |

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

root@localhost 11:28:29> 

root@localhost 11:31:50> GRANT INSERT ON `iQiYi`.* to 'standby'@'localhost';

Query OK, 0 rows affected (0.00 sec)

root@localhost 11:32:08> show grants for 'standby'@'localhost';

+----------------------------------------------------------------------------------------------------------------+

| Grants for standby@localhost                                                                                   |

+----------------------------------------------------------------------------------------------------------------+

| GRANT USAGE ON *.* TO 'standby'@'localhost' IDENTIFIED BY PASSWORD '*68400CF212112D85B99EB397ADCB27748218BFAE' |

| GRANT ALL PRIVILEGES ON `iQiYi`.* TO 'standby'@'localhost'                                                     |

+----------------------------------------------------------------------------------------------------------------+

2 rows in set (0.00 sec)

root@localhost 11:32:10>

mysqldump专业备份命令

2018-06-01 补充

mysql> desc app01_identity;

+-----------+-------------+------+-----+-------------------+-------+

| Field     | Type        | Null | Key | Default           | Extra |

+-----------+-------------+------+-----+-------------------+-------+

| app_id    | varchar(20) | NO   | PRI | NULL              |       |

| active    | int(11)     | NO   |     | NULL              |       |

| last_time | timestamp   | YES  |     | CURRENT_TIMESTAMP |       |

| capbility | int(11)     | YES  |     | 0                 |       |

+-----------+-------------+------+-----+-------------------+-------+

4 rows in set (0.00 sec)

mysql> # 使用 ALTER 修改时间字段自动更新为当前时间，即记录这条数据最后更新的时间

mysql> ALTER TABLE app01_identity change last_time last_time timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '最后更新时间';

Query OK, 1 row affected (0.01 sec)

Records: 1  Duplicates: 0  Warnings: 0

mysql>

mysql> desc app01_identity;

+-----------+-------------+------+-----+-------------------+-----------------------------+

| Field     | Type        | Null | Key | Default           | Extra                       |

+-----------+-------------+------+-----+-------------------+-----------------------------+

| app_id    | varchar(20) | NO   | PRI | NULL              |                             |

| active    | int(11)     | NO   |     | NULL              |                             |

| last_time | timestamp   | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |

| capbility | int(11)     | YES  |     | 0                 |                             |

+-----------+-------------+------+-----+-------------------+-----------------------------+

4 rows in set (0.00 sec)

mysql> select * from app01_identity;

+------------------+--------+---------------------+-----------+

| app_id           | active | last_time           | capbility |

+------------------+--------+---------------------+-----------+

| F9E86B425CC0CD4D |      1 | 2018-05-22 12:18:21 |         1 |

+------------------+--------+---------------------+-----------+

1 row in set (0.00 sec)

# 执行更新操作： queryset_obj.update(active=2, capbility=0)

# 注意：update操作只有QuerySet对象才能使用，单个的obj对象是不能用的

# 即：先filter，查询出QuerySet，然后再执行QuerySet.update(...)

mysql>

mysql> select * from app01_identity;

+------------------+--------+---------------------+-----------+

| app_id           | active | last_time           | capbility |

+------------------+--------+---------------------+-----------+

| F9E86B425CC0CD4D |      2 | 2018-06-01 14:33:02 |         0 |

+------------------+--------+---------------------+-----------+

1 row in set (0.00 sec)

mysql>

查看注释和建表语句

mysql> show full columns from app01_identity;

+-----------+-------------+-----------------+------+-----+-------------------+-----------------------------+---------------------------------+--------------------+

| Field     | Type        | Collation       | Null | Key | Default           | Extra                       | Privileges                      | Comment            |

+-----------+-------------+-----------------+------+-----+-------------------+-----------------------------+---------------------------------+--------------------+

| app_id    | varchar(20) | utf8_general_ci | NO   | PRI | NULL              |                             | select,insert,update,references |                    |

| active    | int(11)     | NULL            | NO   |     | NULL              |                             | select,insert,update,references |                    |

| last_time | timestamp   | NULL            | NO   |     | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | select,insert,update,references | 最后更新时间 |

| capbility | int(11)     | NULL            | YES  |     | 0                 |                             | select,insert,update,references |                    |

+-----------+-------------+-----------------+------+-----+-------------------+-----------------------------+---------------------------------+--------------------+

4 rows in set (0.01 sec)

mysql> show create table app01_identity;

+----------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Table          | Create Table                                                                                                                                                                                                                                                                                                        |

+----------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| app01_identity | CREATE TABLE `app01_identity` (

  `app_id` varchar(20) NOT NULL,

  `active` int(11) NOT NULL,

  `last_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '最后更新时间',

  `capbility` int(11) DEFAULT '0',

  PRIMARY KEY (`app_id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 |

+----------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

mysql>

MySQL里 in 的使用

select  *  from  table  where   uname  in(select  uname  from  user);

select  *  from  table  where   uname  in('aaa','bbb','ccc','ddd','eee','ffff');

MySQL结合子查询进行批量删除

mysql> delete from identity

    -> where app_id in(

    ->     select tb.app_id from

    ->     ( select app_id from identity where app_id like '%\_%' and charge=1 and active=1)tb

    -> );

Query OK, 17 rows affected (0.00 sec)

mysql>

mysql> delete from identity where app_id in( select tb.app_id from ( select app_id from identity where app_id like '%\_%' and charge=1 and active=1)tb );

Query OK, 322 rows affected (0.01 sec)

mysql>

SQL命令查看MySQL数据库大小

# 存放了其他的数据库的信息

use information_schema;

# 查看所有数据的大小

select concat(round(sum(data_length/1024/1024),2),'MB') as data from tables;

# 查看指定数据库(school)的大小

select concat(round(sum(data_length/1024/1024),2),'MB') as data from tables where table_schema='school';

# 查看指定数据库(school)指定表(student)的大小

select concat(round(sum(data_length/1024/1024),2),'MB') as data from tables where table_schema='school' and table_name='student';

# 获取指定表的行数

SELECT COUNT(*) FROM student;

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记录MySQL的一些基础操作

MySQL建表操作

为表的字段添加索引

alter table 修改表结构

1.alter 增加主键索引

2.alter删除主键索引（然后再添加主键索引）

3.alter删除普通索引以及添加普通索引

4.alter 修改字段

5.alter 添加列

6.查看表字段的注释

7.添加注释

8.对字段前n个字符创建索引

9.更该索引

10.为表的多个字段创建联合索引

11.删除索引

12.创唯一索引（非主键）

Finnaly

alter添加字段到指定的位置

INSERT 和 UPDATE

MYSQLDUMP

降序/升序/limit

like 模糊匹配

常用函数

创建新用户并授权

只使用 grant 创建用户并授权

使用 create 和 grant 创建用户并授权

查看某个用户的授权情况

授权局域网内主机远程连接数据库

远端连接的命令：

INVOKE收回某个授权/反向查看ALL PRIVILEGES都有哪些具体权限

mysqldump专业备份命令

SQL命令查看MySQL数据库大小

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只使用 `grant` 创建用户并授权

使用 `create` 和 `grant` 创建用户并授权