MySQL 5.7 database management application combat (a)

1. Modify the mysql database prompt

1.1 mysql login prompt temporary modification, after the end of the session failed

mysql> prompt \u@\h [\d] \r:\m:\s->
PROMPT set to '\u@\h [\d] \r:\m:\s->'
root@localhost [(none)] 09:18:10->\q

1.2 mysql login prompt permanent modification

In the my.cnf configuration file, add [mysql] under the following modules (note, not [mysqld]) saved, without having to restart MySQL, exit the current session, you can log in again; if you add in my.cnf, you can use \, to avoid problems caused by the escape

[root@192168066012_MySQL_5_7_27 ~]# vim /etc/my.cnf
[mysql]
prompt=\\u@\\h [\d] \\r:\\m:\\s->

2 use the help in the mysql

By default, MySQL command is case-insensitive;
Help <Command> # methods can view the specific command

root@localhost [(none)] 09:27:28->help show;
Name: 'SHOW'
Description:
SHOW has many forms that provide information about databases, tables,
columns, or status information about the server. This section describes
those following:

SHOW {BINARY | MASTER} LOGS
SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
SHOW CHARACTER SET [like_or_where]
SHOW COLLATION [like_or_where]
SHOW [FULL] COLUMNS FROM tbl_name [FROM db_name] [like_or_where]
SHOW CREATE DATABASE db_name
SHOW CREATE EVENT event_name
SHOW CREATE FUNCTION func_name
SHOW CREATE PROCEDURE proc_name
SHOW CREATE TABLE tbl_name
SHOW CREATE TRIGGER trigger_name
SHOW CREATE VIEW view_name
SHOW DATABASES [like_or_where]
SHOW ENGINE engine_name {STATUS | MUTEX}
SHOW [STORAGE] ENGINES
...省略

3 Set and modify MySQL USER password

3.1 USER command line to set the password method

Examples of single password provided #MySQL

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot password "boyu123"

#MySQL multi-instance password

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot password 'boyu123' -S /application/mysql/data/3306/mysql.sock

3.2 Method root password modification command <commonly used method>

#MySQL single instance Change Password

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot -pboyu123 password 'boyu1234'

#MySQL multi-instance Change Password

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot -pboyu123 password 'boyu1234' -S /application/mysql/data/3306/mysql.sock

3.3 sql statement modified method <method is dangerous>

# Change the root password for boyu123

root@localhost [(none)] 09:43:22->update mysql.user set authentication_string=password('boyu123') where user='root';
Query OK, 0 rows affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 1

#重新加载使配置立即生效
root@localhost [(none)] 09:44:33->flush privileges;
Query OK, 0 rows affected (0.00 sec)

Tip:
. A must specify where the conditions, otherwise all the password is changed, danger! ! !
b. You must use password () function encryption changes

4 single instance of MySQL USER recover lost passwords

First stop MySQL 4.1 database

Single Instance stop MySQL database

[root@192168066012_MySQL_5_7_27 ~]# /etc/init.d/mysqld stop
Shutting down MySQL. SUCCESS!

4.2 Use --skip-grant-tables start the MySQL database, ignoring authorization login authentication

Command line, type the following command
mysqld_safe --skip-grant-tables --user = mysql &
input mysql can skip to verify access to the database
mysql
Update update root password
mysqladmin elegant close the database
mysql -uroot -pboyu123 you can log in the database
Tip: At startup, plus --skip-grant-tables parameter, omit the authorization form validation

4.3 --skip-grant-tables method of operating parameters

#跳过授权表验证
[root@192168066012_MySQL_5_7_27 ~]# mysqld_safe --skip-grant-tables --user=mysql &
[1] 130775
[root@192168066012_MySQL_5_7_27 ~]# 2019-07-31T13:57:05.294289Z mysqld_safe Logging to '/application/mysql/logs/mysql_5_7_27.err'.
2019-07-31T13:57:05.327331Z mysqld_safe Starting mysqld daemon with databases from /application/mysql/data

#检查一下数据库进程
[root@192168066012_MySQL_5_7_27 ~]# ps -ef|grep 3306
root        359  99061  0 21:57 pts/1    00:00:00 grep --color=auto 3306
mysql    131036 130775  2 21:57 pts/1    00:00:00 /application/mysql/bin/mysqld --basedir=/application/mysql --datadir=/application/mysql/data --plugin-dir=/application/mysql/lib/plugin --user=mysql --skip-grant-tables --log-error=/application/mysql/logs/mysql_5_7_27.err --pid-file=/application/mysql/mysqld.pid --socket=/application/mysql/tmp/mysql.sock --port=3306
#无需密码，即可登入数据库
[root@192168066012_MySQL_5_7_27 ~]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
...省略
#更新root密码
root@localhost [(none)] 10:03:30->update mysql.user set authentication_string=password('boyu123') where user='root';
Query OK, 0 rows affected, 1 warning (0.01 sec)
Rows matched: 1  Changed: 0  Warnings: 1

#刷新授权表
root@localhost [(none)] 10:04:28->flush privileges;
Query OK, 0 rows affected (0.00 sec)

root@localhost [(none)] 10:04:32->\q
Bye
#优雅停止数据库
[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot -pboyu123 shutdown
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
2019-07-31T14:05:16.946425Z mysqld_safe mysqld from pid file /application/mysql/mysqld.pid ended
[1]+  Done                    mysqld_safe --skip-grant-tables --user=mysql
#启动数据库
[root@192168066012_MySQL_5_7_27 ~]# /etc/init.d/mysqld start
Starting MySQL. SUCCESS!
#此时，就可以使用新密码登录数据库了
[root@192168066012_MySQL_5_7_27 ~]# mysql -uroot -pboyu123
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
...省略
root@localhost [(none)] 10:05:42->

More than five instances of MySQL USER recover lost passwords

First stop MySQL 5.1 database

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot -p"boyu123" -S /application/mysql/data/3306/mysql.sock shutdown

5.2 Use --skip-grant-table start the MySQL database, ignoring authorization login authentication

[root@192168066012_MySQL_5_7_27 ~]# /application/mysql/bin/mysqld_safe --skip-grant-tables --port=3306 --user=mysql --character_set_server=utf8 --socket=/application/mysql/data/3306/mysql.sock --datadir=/application/mysql/data/3306/data --pid-file=/application/mysql/data/3306/mysql.pid --log-bin=/application/mysql/data/3306/mysql-bin --server-id=1 --log-error=/application/mysql/data/3306/mysql_boyu3306.err &

5.3 No password database, change the root password, refresh the grant tables

[root@192168066012_MySQL_5_7_27 ~]# mysql -S /application/mysql/data/3306/mysql.sock
Welcome to the MySQL monitor.  Commands end with ; or \g.
...省略
mysql> update mysql.user set authentication_string=password('boyu123') where user='root';
Query OK, 0 rows affected, 1 warning (0.01 sec)
Rows matched: 1  Changed: 0  Warnings: 1

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

mysql> \q
Bye

5.4 Stop 3306 database, and use the new password database

[root@192168066012_MySQL_5_7_27 ~]# mysqladmin -uroot -p"boyu123" -S /application/mysql/data/3306/mysql.sock shutdown
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
2019-08-08T03:37:09.248027Z mysqld_safe mysqld from pid file /application/mysql/data/3306/mysql.pid ended
[1]+  Done                    /application/mysql/bin/mysqld_safe --skip-grant-tables --port=3306 --user=mysql --character_set_server=utf8 --socket=/application/mysql/data/3306/mysql.sock --datadir=/application/mysql/data/3306/data --pid-file=/application/mysql/data/3306/mysql.pid --log-bin=/application/mysql/data/3306/mysql-bin --server-id=1 --log-error=/application/mysql/data/3306/mysql_boyu3306.err
#启动3306数据库
[root@192168066012_MySQL_5_7_27 ~]# /application/mysql/bin/mysqld --port=3306 --user=mysql --character_set_server=utf8 --socket=/application/mysql/data/3306/mysql.sock --datadir=/application/mysql/data/3306/data --pid-file=/application/mysql/data/3306/mysql.pid --log-bin=/application/mysql/data/3306/mysql-bin --server-id=1 --log-error=/application/mysql/data/3306/mysql_boyu3306.err &
#新密码登录数据库
[root@192168066012_MySQL_5_7_27 ~]# mysql -uroot -pboyu123 -S /application/mysql/data/3306/mysql.sock
...省略
mysql>

6 SQL Structured Query Language

6.1 What is SQL?

SQL (Structured Query Language) is a structured query language (programming language and database query), which is a method for the language data in relational database operations and defined

6.2 Common SQL statement classification

a. DDL --- Data Definition Language (CREATE, ALTER, DROP)
full name (Data Definition Language), database, create a new table or delete tables, indexes, and so added to the table, the action is part of a query
b. DML --- data Manipulation language (SELECT, INSERT, dELETE, UPDATE )
the full name (data Manipulation language), a database, modify, and delete rows in the table (data), also known as action query language
c. DCL --- data control language (GRANT, REVOKE, COMMIT, ROLLBACK)
the full name (Data Control Language), a database, license, determining a single user and group access to the database objects

7 Create a database

Note that the library name can not start with digital
command syntax: create database <database name>

• The default configuration database, create the equivalent of the Latin character set database

root@localhost [(none)] 10:20:09-> create database boyu;

• Create database character set gbk

root@localhost [(none)] 10:20:09-> create database boyu_gbk DEFAULT CHARACTER SET gbk COLLATE gbk_chinese_ci;

• Create database character set utf8

root@localhost [(none)] 10:20:09-> create database boyu_utf8 DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

• View the database character set has been created

root@localhost [(none)] 10:20:09-> show create database boyu_utf8\G
+-----------+--------------------------------------------------------------------+
| Database  | Create Database                                                    |
+-----------+--------------------------------------------------------------------+
| boyu_utf8 | CREATE DATABASE "boyu_utf8" /*!40100 DEFAULT CHARACTER SET utf8 */ |
+-----------+--------------------------------------------------------------------+
1 row in set (0.00 sec)

Tip:
. A character set is inconsistent database Chinese garbled the contents of the culprit
. B if the compiler when installed, specifies a particular character set, then later creates a corresponding database character set, you need to specify the character set.
c. the enterprise how to create a database?
Determine the character set based on program development (usually UTF8)
compile time specified character set, and then again when created, can be created by default; for example:
-DDEFAULT_CHARSET = utf8 \
-DDEFAULT_COLLATION = utf8_general_ci \
the Create Database boyu;
compiled without specify the character set, or specify a different character sets and procedures, how to solve?
Create a database, you can specify the character set;

8 shows the database

Command Syntax: show databases;

• Displays all the current database

root@localhost [(none)] 10:31:00->show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| boyu               |
| boyu_gbk           |
| boyu_utf8          |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
7 rows in set (0.00 sec)

• Display boyu database

root@localhost [(none)] 10:31:05->show databases like 'boyu';
+-----------------+
| Database (boyu) |
+-----------------+
| boyu            |
+-----------------+
1 row in set (0.00 sec)

• Displayed in multiple databases boyu beginning, as a wildcard%

root@localhost [(none)] 10:31:36->show databases like 'boyu%';
+------------------+
| Database (boyu%) |
+------------------+
| boyu             |
| boyu_gbk         |
| boyu_utf8        |
+------------------+
3 rows in set (0.00 sec)

9 Delete Database

Command syntax: drop database <database name>

• Delete the database named boyu_utf8

root@localhost [(none)] 10:31:43->drop database boyu_utf8;
Query OK, 0 rows affected (0.00 sec)

9.1 subconscious learning View Help

root@localhost [(none)] 10:39:10->help drop database;
Name: 'DROP DATABASE'
Description:
Syntax:
DROP {DATABASE | SCHEMA} [IF EXISTS] db_name

DROP DATABASE drops all tables in the database and deletes the
database. Be very careful with this statement! To use DROP DATABASE,
you need the DROP privilege on the database. DROP SCHEMA is a synonym
for DROP DATABASE.

10 connecting to the database

Command Syntax: use <database name>

• Connection / database into the boyu

root@localhost [(none)] 10:45:04->use boyu;
Database changed

• View the database is currently located

root@localhost [boyu] 10:45:07->select database();
+------------+
| database() |
+------------+
| boyu       |
+------------+
1 row in set (0.00 sec)

• View the current version of the database

root@localhost [boyu] 10:45:24->select version();
+------------+
| version()  |
+------------+
| 5.7.27-log |
+------------+
1 row in set (0.00 sec)

• Check the system / database current time

root@localhost [boyu] 10:45:33->select now();
+---------------------+
| now()               |
+---------------------+
| 2019-07-31 22:45:53 |
+---------------------+
1 row in set (0.00 sec)

11 Creating MySQL user and give the user permissions

11.1 with the help grant View command help

By looking at the help grant commands, you can easily find and create user authorization examples

root@localhost [boyu] 10:45:53->help grant;
...省略
CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'password';
GRANT ALL ON db1.* TO 'jeffrey'@'localhost';
GRANT SELECT ON db2.invoice TO 'jeffrey'@'localhost';
ALTER USER 'jeffrey'@'localhost' WITH MAX_QUERIES_PER_HOUR 90;

11.2 operation and maintenance personnel to create a user commonly used method, using a grant to create a user simultaneously authority delegation, for example:

GRANT ALL ON db1.* TO 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';

11.3 grant command help which provides a user with the create command to create, and then grant the authorization method, namely, to create a separate user and authorization privileges, for example:

CREATE USER 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';
GRANT ALL ON db1.* TO 'jeffrey'@'localhost';
以上两条命令相当于下面一条命令：
GRANT ALL ON db1.* TO 'jeffrey'@'localhost' IDENTIFIED BY 'mypass';

11.4 Create a user command and authorized by grant

grant语法：grant all privileges on dbname.* to ‘username’@‘localhost’ identified by 'mypass';

grant	all privileges	on dbname.*	to username@localhost	identified by 'mypass'
Authorization command	The corresponding authority	Objectives: Library and tables	The user name and client host	user password

Description: By all rights the user username dbname database management on the authorization host localhost, password passwd. Wherein username, dbname, passwd can be modified according to the Operational

• Creating boyu user, password boyu123, and authorize access rights to the database boyu

root@localhost [boyu] 11:02:41->grant all privileges on boyu.* to 'boyu'@'localhost' identified by 'boyu123';
Query OK, 0 rows affected, 1 warning (0.00 sec)

• Refresh authority table

root@localhost [boyu] 11:03:13->flush privileges;
Query OK, 0 rows affected (0.00 sec)

• Query status

root@localhost [boyu] 11:06:03->select user,host from mysql.user;
+------+-----------+
| user | host      |
+------+-----------+
| boyu | localhost |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)

• Have permission to view boyu

root@localhost [boyu] 11:10:18->show grants for 'boyu'@'localhost';
+--------------------------------------------------------+
| Grants for boyu@localhost                              |
+--------------------------------------------------------+
| GRANT USAGE ON *.* TO 'boyu'@'localhost'               |
| GRANT ALL PRIVILEGES ON "boyu".* TO 'boyu'@'localhost' |
+--------------------------------------------------------+
2 rows in set (0.00 sec)

11.5 Authorization host LAN remote database connection

According grant command syntax, we know oldboy @ localhost position is authorized to access the database host, localhost can use the domain name, IP address, or IP segment instead

a. Matching Percent

root@localhost [boyu] 11:10:41->grant all on boyu.* to boyu@'192.168.66.%' identified by 'boyu123';
Query OK, 0 rows affected, 1 warning (0.01 sec)

root@localhost [boyu] 11:18:50->flush privileges;
Query OK, 0 rows affected (0.00 sec)

b. Method subnet mask

root@localhost [boyu] 11:18:55->grant all on boyu.* to boyu1@'192.168.66.0/255.255.255.0' identified by 'boyu123';
Query OK, 0 rows affected, 1 warning (0.00 sec)

root@localhost [boyu] 11:19:34->flush privileges;
Query OK, 0 rows affected (0.00 sec)

c. authorize single IP remote connections

root@localhost [boyu] 11:19:37->grant all on boyu.* to boyu2@'192.168.66.11' identified by 'boyu123';
Query OK, 0 rows affected, 1 warning (0.00 sec)

root@localhost [boyu] 11:19:44->flush privileges;
Query OK, 0 rows affected (0.00 sec)

root@localhost [boyu] 11:19:46->select user,host from mysql.user;
+-------+----------------------------+
| user  | host                       |
+-------+----------------------------+
| boyu  | 192.168.66.%               |
| boyu1 | 192.168.66.0/255.255.255.0 |
| boyu2 | 192.168.66.11              |
| boyu  | localhost                  |
| root  | localhost                  |
+-------+----------------------------+
5 rows in set (0.00 sec)

12 Delete MySQL system account surplus

• drop user "user" @ "host domain", note the quotation marks, which can be single or double quotation marks, but can not be quoted

root@localhost [boyu] 11:20:02->drop user 'boyu1'@'192.168.66.0/255.255.255.0';
Query OK, 0 rows affected (0.01 sec)

root@localhost [boyu] 12:47:53->delete from mysql.user where user='boyu2' and host='192.168.66.11';
Query OK, 1 row affected (0.00 sec)

root@localhost [boyu] 01:09:50->select user,host from mysql.user;
+------+-----------+
| user | host      |
+------+-----------+
| boyu | localhost |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)

• Note: If the drop can not be deleted (usually special characters or uppercase), you can delete (to BO # Y & U0 @ 07 users, BOYU host, for example) in the following manner

root@localhost [boyu] 01:27:43->select user,host from mysql.user;
+------------+-----------+
| user       | host      |
+------------+-----------+
| BO#Y&U0@07 | boyu      |
| boyu       | localhost |
| root       | localhost |
+------------+-----------+
3 rows in set (0.00 sec)

root@localhost [boyu] 01:30:05->delete from mysql.user where user='BO#Y&U0@07' and host='boyu';
Query OK, 1 row affected (0.00 sec)

root@localhost [boyu] 01:30:55->select user,host from mysql.user;
+------+-----------+
| user | host      |
+------+-----------+
| boyu | localhost |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)

root@localhost [boyu] 01:31:01->flush privileges;
Query OK, 0 rows affected (0.00 sec)

13 ALL PRIVILEGES which contains what authority?

SELECT	INSERT	UPDATE	DELETE	CREATE	DROP	INDEX	ALTER	CREATE TEMPORARY TABLES
Inquire	insert	Update	delete	Create a library and table	Delete a library and table	index	modify	Create a temporary table

LOCK TABLES	EXECUTE	CREATE VIEW	SHOW VIEW	CREATE ROUTINE	ALTER ROUTINE	EVENT	TRIGGER	REFERENCES
Lock table	carried out	Create a view	Show View	Create a stored procedure	Modify the stored procedure	event	trigger	Foreign key

Tip: Permissions that authorization, authorized users can meet the business needs of the smallest, rather than to authorize "ALL PRIVILEGES"

• Authorized users have boyu1 "select, insert, update, delete, create, drop" library of permission to perform boyu

root@localhost [boyu] 01:59:22->CREATE USER 'boyu1'@'localhost' IDENTIFIED BY 'boyu123';
Query OK, 0 rows affected (0.00 sec)

root@localhost [boyu] 02:00:20->grant select,insert,update,delete,create,drop ON `boyu`.* TO 'boyu1'@'localhost';
Query OK, 0 rows affected (0.00 sec)

root@localhost [boyu] 02:00:28->show grants for boyu1@localhost;
+---------------------------------------------------------------------------------------+
| Grants for boyu1@localhost                                                            |
+---------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'boyu1'@'localhost'                                             |
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP ON "boyu".* TO 'boyu1'@'localhost' |
+---------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

• Boyu2 create user and grant "select, insert, update, delete, create, drop" permissions to perform boyu library

root@localhost [boyu] 01:58:31->grant select,insert,update,delete,create,drop on boyu.* to 'boyu2'@'localhost' identified by 'boyu123';
Query OK, 0 rows affected, 1 warning (0.01 sec)

root@localhost [boyu] 01:59:07->show grants for boyu2@localhost;
+---------------------------------------------------------------------------------------+
| Grants for boyu2@localhost                                                            |
+---------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'boyu2'@'localhost'                                             |
| GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP ON "boyu".* TO 'boyu2'@'localhost' |
+---------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

How 14 enterprise production environment authorized user rights

14.1 Authorization blog, CMS and other products

For web users authorized to connect as far as possible to minimize principle, many open source software is the web interface installed, therefore, the conventional case to grant select, insert, update, delete permissions can be, for example discuz, bbs and other open source software, but also need to grant create, drop more dangerous permissions

root@localhost [boyu] 02:00:39-> grant select,insert,update,delete,create,drop ON blog.* to 'blog'@'192.168.66.%' identified by 'boyu123';

14.2 generate a database table, you need to recover create, drop privileges

root@localhost [boyu] 02:00:39-> REVOKE create ON blog.* FROM 'blog'@'192.168.66.%'; 
root@localhost [boyu] 02:00:39-> REVOKE drop ON blog.* FROM 'blog'@'192.168.66.%';