Linux运维必会MySQL 30道基础命令

mysql-uroot -poldboy123 -S/data/3306/mysql.sock

1.2查看数据库版本及当前登录用户是什么？

mysql> select version();

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

| version() |

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

| 5.6.36   |

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

mysql>select user();

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

| user()        |

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

| root@localhost |

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

1.3创建GBK字符集的数据库oldboy，并查看已建库的完整语句

mysql> create database oldboy2 character set gbk collate gbk_chinese_ci;

Query OK, 1 row affected (0.06 sec)

mysql> show databases;

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

| Database           |

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

| information_schema |

| mysql              |

| oldboy             |

| oldboy2            |

| performance_schema |

| world              |

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

mysql> show create database oldboy;

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

| Database | Create Database                                                 |

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

| oldboy   |CREATE DATABASE `oldboy` /*!40100 DEFAULT CHARACTER SET utf8 */ |

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

1.4创建用户oldboy，使之可以管理数据库oldboy

grant all on oldboy2.* to oldboy2@‘localhost‘identified by ‘123‘

1.5查看创建的用户oldboy拥有哪些权利

mysql>show grants for oldboy2@‘localhost‘;

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

| Grants for oldboy2@localhost                                                                                  |

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

| GRANT USAGE ON *.* TO ‘oldboy2‘@‘localhost‘IDENTIFIED BY PASSWORD ‘*23AE809DDACAF96AF0FD78ED04B6A265E05AA257‘ |

| GRANT ALL PRIVILEGES ON `oldboy2`.* TO‘oldboy2‘@‘localhost‘                                                  |

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

1.6查看当前数据库里有哪些用户

mysql>select user,host from mysql.user;

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

| user    |host       |

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

| oldboy1 | 10.0.0.%   |

| root    |127.0.0.1  |

| oldboy  |172.16.1.% |

| oldboy2 | localhost  |

| root    |localhost  |

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

1.7进入oldboy数据库

mysql> use oldboy2

1.8创建一innodb引擎字符集为GBK表test，字段为id和namevarchar(16)，查看建表结构及语句

1.8.1创建

mysql> use oldboy2

Database changed

mysql> create table test(

    -> id int(4),

    -> name varchar(16)

    -> ) engine=innodb default charset=gbk;

Query OK, 0 rows affected (0.09 sec)

mysql> show tables;

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

| Tables_in_oldboy2 |

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

| test             |

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

1.8.2查看表结构

1.8.2.1 方法一：

mysql> desc test;

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

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

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

| id    |int(4)      | YES  |     |NULL    |       |

| name  |varchar(16) | YES  |     | NULL   |       |

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

1.8.2.2 方法二：

mysql>show columns from test;

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

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

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

| id    |int(4)      | YES  |     |NULL    |       |

| name  |varchar(16) | YES  |     | NULL   |       |

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

1.8.3查看表结构SQL语句

mysql>show create table test;

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

| Table | Create Table                                                                                                           |

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

| test  |CREATE TABLE `test` (

  `id`int(4) DEFAULT NULL,

  `name`varchar(16) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=gbk |

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

1.9插入一条数据1,oldboy

mysql> insert into test values(1,‘oldboy‘);

mysql> select * from test;

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

| id   |name   |

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

|    1 |oldboy |

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

1.10批量插入数据 2，老男孩，3，etiantian.要求中文不能乱码

mysql> insert into test values(2,‘老男孩‘),(3,‘etiantian‘);

mysql> select * from test ;

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

| id   |name      |

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

|    1 |oldboy    |

|    2 | 老男孩    |

|    3 |etiantian |

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

1.11查询插入的所有记录，查询名字为oldboy的记录。查询id大于1的记录

1.11.1查看插入的所有记录

mysql>select * from test

    -> ;

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

| id   |name      |

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

|    1 |oldboy    |

|    2 | 老男孩    |

|    3 |etiantian |

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

1.11.2查询名字为oldboy的记录

mysql> select * from test where name=‘oldboy‘;

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

| id   |name   |

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

|    1 |oldboy |

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

1.11.3查看id大于1的记录

mysql>select * from test where id>1;

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

| id   |name      |

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

|    2 | 老男孩    |

|    3 |etiantian |

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

1.12把数据id等于1的名字oldboy更改为oldbgirl

updatetest set  name=‘oldgirl‘ where id=1;

mysql>select * from test;

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

| id   |name      |

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

|    1 |oldgirl   |

|    2 | 老男孩    |

|    3 |etiantian |

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

1.13在字段name前插入age字段，类型tinyint(2)

mysql>alter table test add age tinyint(2)after id;

mysql> desc test;

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

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

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

| id    |int(4)      | YES  |     |NULL    |       |

| age   |tinyint(2)  | YES  |     |NULL    |       |

| name  |varchar(16) | YES  |     | NULL   |       |

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

1.14备份oldboy库及Mysql库

mysqldump –B –compact oldboy > /opt/bak.sql

1.15删除表中的所有数据，并查看

1.15.1delete是逻辑删除表中的数据，一列一列的删除表中的数据，速度比较慢

delete from rest;

1.15.2truncate是物理删除表中的数据，一次性全部都给清空表中数据，速度很快

truncate table test;

1.16删除表test和oldboy数据库并查看

1.16.1删除表

drop table test;

1.16.2删除数据库oldboy

mysql> show databases;

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

| Database           |

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

| information_schema |

| mysql              |

| oldboy             |

| performance_schema |

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

4 rows in set (0.00 sec)

mysql> drop database oldboy;

mysql> show databases;    

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

| Database          |

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

| information_schema |

| mysql              |

| performance_schema |

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

1.17linux命令行恢复以上删除数据

mysql -uroot -poldboy123 -S/data/3306/mysql.sock</opt/bak.sql

1.18把GBK字符集修改为UTF8（可选,注意此题有陷阱）

1.18.1查看一下字符集

mysql> mysql> show variables like‘character_set%‘;

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

| Variable_name            | Value                                     |

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

| character_set_client     | utf8                                      |

| character_set_connection | utf8                                      |

| character_set_database   | utf8                                      |

| character_set_filesystem | binary                                    |

| character_set_results    | utf8                                      |

| character_set_server     | utf8                                      |

| character_set_system     | utf8                                      |

| character_sets_dir       |/application/mysql-5.6.36/share/charsets/ |

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

1.18.2设置字符集

mysql> set global character_set_database =utf8;

1.19Mysql密码丢了，如何找回实战

1.20Mysql内中文数据乱码的原理及如何防止乱码

1.20.1数据库字符集

mysql> show variables like ‘character_set%‘;

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

| Variable_name            | Value                                     |

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

| character_set_client     | utf8                                      |

| character_set_connection | utf8                                      |

| character_set_database   | utf8                                      |

| character_set_filesystem | binary                                    |

| character_set_results    | utf8                                      |

| character_set_server     | utf8                                      |

| character_set_system     | utf8                                      |

| character_sets_dir       |/application/mysql-5.6.36/share/charsets/ |

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

1.20.2系统字符配置文件

[root@mysql data]# cat /etc/sysconfig/i18n

LANG="en_US.UTF-8"

SYSFONT="latarcyrheb-sun16"

1.21 在把id列设置为主键，在name字段上创建普通索引

mysql> desc oldboy.test;

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

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

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

| id    |int(4)      | YES  |     |NULL    |       |

| name  |varchar(16) | YES  |     | NULL   |       |

| age   |int(4)      | YES  |     |NULL    |       |

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

alter table oldboy.test add primarykey(id);

1.21.1在name字段上创建普通索引

方法一：alter table oldboy,test addindexindex_name(name)

方法二：create index index_name onoldboy.test(name);

1.22在字段name后插入手机号字段（shouji）,类型char(11)

mysql> alter table test add shou char(11) aftername;

mysql> desc test;

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

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

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

| id     |int(4)      | YES  | MUL | NULL    |      |

| name   |varchar(16) | YES  |     | NULL   |       |

| shou   |char(11)    | YES  |     |NULL    |       |

| age    |int(4)      | YES  |     |NULL    |       |

| shouji | char(11)    | YES |     | NULL    |      |

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

1.23所有字段上插入两条记录（自行设定数据）

mysql> insert into test values(6,‘mysql‘,‘mei‘,‘21‘,‘1794225527‘),(7,‘mysql1‘,‘mein‘,‘21‘,‘15095,‘15095445967‘);

mysql> select * from test;

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

| id   |name    | shou | age  | shouji     |

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

|    1 |oldboy  | NULL |   21 | NULL        |

|    3 |oldboy3 | NULL |   21 | NULL        |

|    4 |oldboy4 | NULL |   21 | NULL        |

|    5 | 小明    | NULL |   21 | NULL        |

|    6 |mysql   | mei  |   21| 1794225527  |

|    7 |mysql1  | mein |   21 | 15095445967 |

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

1.24在手机字段上对前八个字符创建普通索引

mysql> alter table test add index index_shouji(shouji(8));

mysql> desc test;

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

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

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

| id     |int(4)      | YES  | MUL | NULL    |      |

| name   |varchar(16) | YES  |     | NULL   |       |

| shou   |char(11)    | YES  |     |NULL    |       |

| age    |int(4)      | YES |     | NULL    |      |

| shouji | char(11)    | YES | MUL | NULL    |       |

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

1.25查看创建的索引及索引类型等信息

mysql>mysql> show index from test\G

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

       Table: test

  Non_unique: 1

    Key_name: name_idx

 Seq_in_index: 1

 Column_name: id

   Collation: A

 Cardinality: 6

    Sub_part: NULL

      Packed: NULL

        Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

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

       Table: test

  Non_unique: 1

    Key_name: index_shouji

 Seq_in_index: 1

 Column_name: shouji

   Collation: A

 Cardinality: 6

    Sub_part: 8

      Packed: NULL

         Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

2 rows in set (0.00 sec

1.26删除name，shouji列的索引

mysql> alter table test drop index index_shouji;

mysql> show index from test\G

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

        Table: test

  Non_unique: 1

    Key_name: name_idx

 Seq_in_index: 1

 Column_name: id

   Collation: A

 Cardinality: 6

    Sub_part: NULL

      Packed: NULL

        Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

1 row in set (0.00 sec)

1.27对name列的前6个字符以及手机列的前8个字符组建联合索引

alter table test add indexindex_name_shouji(name(6),shouji(8));

mysql> show index from test\G

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

       Table: test

  Non_unique: 1

    Key_name: name_idx

 Seq_in_index: 1

 Column_name: id

   Collation: A

 Cardinality: 6

    Sub_part: NULL

      Packed: NULL

        Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

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

       Table: test

  Non_unique: 1

    Key_name: index_name_shouji

 Seq_in_index: 1

 Column_name: name

   Collation: A

 Cardinality: 6

    Sub_part: 6

      Packed: NULL

        Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

*************************** 3. row***************************

       Table: test

  Non_unique: 1

    Key_name: index_name_shouji

 Seq_in_index: 2

 Column_name: shouji

   Collation: A

 Cardinality: 6

    Sub_part: 8

      Packed: NULL

        Null: YES

  Index_type: BTREE

     Comment:

Index_comment:

3 rows in set (0.00 sec)

1.28查询手机号以136开头的，名字为oldboy的记录（次记录要提前插入）

mysql> select * from test where name=‘mysql‘and shouji like ‘179%‘;

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

| id   |name  | shou | age  | shouji    |

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

|    6 |mysql | mei  |   21 | 1794225527 |

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

1.29查询上述语句的执行计划（是否使用联合索引等）

mysql> explain select * from test wherename=‘oldboy‘ and shouji like ‘1%‘;

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

| id | select_type | table | type  | possible_keys     | key               | key_len | ref  | rows | Extra       |

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

|  1 |SIMPLE      | test  | range | index_name_shouji |index_name_shouji | 32      | NULL |    1 | Using where |

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

mysql> explain select * from test where name=‘oldboy‘ and shouji like ‘1%‘\G

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

          id: 1

 select_type: SIMPLE

       table: test

         type: range

possible_keys: index_name_shouji

         key: index_name_shouji

     key_len: 32

         ref: NULL

        rows: 1

       Extra: Using where

1 row in set (0.00 sec)

1.30把test的引擎改成Mysql

mysql> show create table test\G

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

      Table: test

Create Table: CREATE TABLE `test` (

  `id`int(4) DEFAULT NULL,

  `name`varchar(16) DEFAULT NULL,

  `shou`char(11) DEFAULT NULL,

  `age`int(4) DEFAULT NULL,

  `shouji`char(11) DEFAULT NULL,

  KEY`name_idx` (`id`),

  KEY`index_name_shouji` (`name`(6),`shouji`(8))

) ENGINE=InnoDB DEFAULT CHARSET=gbk

mysql> alter table oldboy.test ENGINE=MyISAM;

Query OK, 5 rows affected (0.01 sec)

Records: 5 Duplicates: 0  Warnings: 0

mysql> show create table oldboy.test\G     

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

      Table: test

Create Table: CREATE TABLE `test` (

  `id`int(4) NOT NULL DEFAULT‘0‘,

  `age`tinyint(2) DEFAULTNULL,

  `name`varchar(16) DEFAULTNULL,

  `shouji`char(11) DEFAULTNULL,

  PRIMARYKEY (`id`),

  KEY`index_name_shouji`(`name`(6),`shouji`(8))

) ENGINE=MyISAM DEFAULT CHARSET=gbk

1 row in set (0.00 sec)

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Linux运维必会MySQL 30道基础命令

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