MySQL introduction and installation (I)

1. MySQL Learning route

 Chapter one   Introduction and installation 
 Chapter two   Architecture and basic management 
 The third chapter  SQL Basics 
 Chapter four   Index and 	 Implementation plan 
 The fifth chapter   Storage engine 
 Chapter six   Log management 
 Chapter vii.   Backup and recovery 
 Chapter viii.   Master slave replication and architecture evolution 
 Chapter nine   High availability and read / write separation architecture 
 Chapter ten   Distributed architecture 
 Chapter ten   Comprehensive optimization 
 Chapter 11  NoSQL-redis/mongodb/ES

Search engine database ranking ：https://db-engines.com/en/ranking

2. MySQL Introduce

2.1 Data form

 data ： written words 、 picture 、 video ... Data representation of human cognition 
 Computer ： Binary system 、16 Binary machine language 
 Based on the importance and complexity of the data , We may have different management methods .

 What data is suitable for storage in the database ？
 Of high importance 
 Data with complex relationships 

2.2 Database management system DBMS

RDBMS:  Relational database management system 
 It's more suitable for , Data with high security level requirements and data with complex relationships 

NoSQL: Non relational database management system 
 Suitable for high performance data access , In general, it's cooperation RDBMS For use 
 For big data processing and Analysis , Distributed architecture is better at 

2.3 Database management system type

RDBMS  ：
MySQL 、Oracle、MSSQL（SQL Server）、PG
 
NoSQL：Not Only SQL
 key - value （key-value）：Redis, memcached
 file （document）：Mongodb（ Store historical orders 、 Running water ）、ES（ Search box ）

3. MySQL product line

3.1 MySQL manufacturer

Oracle:  MySQL Official edition 
Redhat:  MariaDB
Percona: PerconaDB

3.2 MySQL Version selection

5.6 :2021 year 2 Month stopped updating . Quit the stage of history immediately .
5.7 :5.7.31+ 
8.0 :8.0.20+

 Version number designation ：
 The core system   5731
 Edge system   8020

3.3 MySQL Software access

www.mysql.com   ---> downloads 
 Enterprise Edition ：Enterprise  ,  The Internet industry generally does not choose .
 Community version ： choice , Enterprises use and learn to use 
 Source package ：source code  .tar.gz, Generally, when looking at the source code, look at the installation   

Binary package ：

Source package ：

3.4 MySQL Installation mode

 General binary version ：  Decompression is used immediately. （ The green version ）
rpm、yum edition ：  download rpm Package or configuration yum Source 
 Source package ：  Compilation and installation , Very slow 

4. MySQL-5.7.28 Binary package installation

4.1 Environmental preparation

（1）  Get ready Centos 7.6 virtual machine 
[root@db01 ~]# hostname -I
10.0.0.61
[root@db01 ~]# hostname
db01

（2）  Clean up the historical environment 
[root@db01 ~]# rpm -qa | grep mariadb
mariadb-libs-5.5.68-1.el7.x86_64
mariadb-server-5.5.68-1.el7.x86_64
mariadb-5.5.68-1.el7.x86_64
[root@db01 ~]# yum remove mariadb-libs.x86_64 -y

(3)  Create users and groups 
[root@db01 ~]# useradd mysql -s /sbin/nologin
[root@db01 ~]# id mysql
 uid=1001(mysql) gid=1001(mysql) groups=1001(mysql)
 
(4)  Create related directories 
#  Create a software catalog 
[root@db01 ~]# mkdir -p /app/database/
#  Create a data directory 
[root@db01 ~]# mkdir -p /data/3306/
#  Create a log directory  
[root@db01 ~]# mkdir -p /binlog/3306/ 

(5)  Set the permissions 
[root@db01 ~]# chown -R mysql.mysql /app/ /data/ /binlog/

4.2 Upload and unzip MySQL Software

[root@db01 ~]# cd /app/database/
[root@db01 database]# tar xf mysql-5.7.30-linux-glibc2.12-x86_64.tar.gz
[root@db01 database]# ln -s mysql-5.7.30-linux-glibc2.12-x86_64 mysql

4.3 Set the environment variable

[root@db01 ~]# vim /etc/profile 
# Add the following lines ： 
export PATH=/app/database/mysql/bin:$PATH
#  Effective configuration  
[root@db01 ~]# source /etc/profile

4.4 Initialize system library table

Tips ：rmp The package automatically completes the initialization operation

#  Installation dependency , Prevent initialization error 
[root@db01 ~]# yum install -y libaio-devel 
#  To initialize 
[root@db01 ~]# mysqld --initialize-insecure --user=mysql --basedir=/app/database/mysql --datadir=/data/3306/

#  The lack of libaio-devel rely on , Initialization error ：
mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory


#  An error that is easy to report ：
[root@db01 ~]# mysqld --initialize-insecure --user=mysql --basedir=/app/database/mysql --datadir=/data/3306/
2022-06-08T14:03:39.492759Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2022-06-08T14:03:39.494239Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2022-06-08T14:03:39.494260Z 0 [ERROR] Aborting

#  reason + solve ： If an error occurs during the first initialization , This error may be reported during the second initialization 
[root@db01 ~]# rm -rf /data/3306/*
[root@db01 ~]# mysqld --initialize-insecure --user=mysql --basedir=/app/database/mysql --datadir=/data/3306/

Expand ：

# 5.7 The initialization mode of subsequent versions 
# mysqld --initialize-insecure --user=mysql --basedir= Software path  --datadir= Data path 
（1） mysqld --initialize
	  Will generate 12 Bit random temporary password （ Administrator user ）, Four types of password complexity .
	  Temporarily generate password , Can only be used to log in . Cannot be used to manage databases . Reset it the first time you log in 
	 [root@db01 data]# mysql -uroot -p'Uh0*xe(eLw(W'
	  mysql> create database test;
	  ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement
	  mysql> alter user root@'localhost' identified by '123';
	  mysql> create database test;
       Or change the password like this ：
      [root@db01 data]# mysqladmin -uroot -p password [email protected]
      #  Enter the initialization password 
      Enter password: 
	  
（2） mysqld --initialize-insecure
	  The administrator password is empty 

# 5.7 Initialization mode of previous version （ for example 5.6）
# /usr/local/mysql/scripts/mysql_install_db --user=mysql --basedir= Software installation path  --datadir= Data directory 
/usr/local/mysql/scripts/mysql_install_db --user=mysql --basedir=/app/database/mysql --datadir=/data/3306/

4.5 Profile Settings

[root@db01 ~]# cat > /etc/my.cnf <<EOF
[mysqld]
user=mysql 
basedir=/app/database/mysql 
datadir=/data/3306/ 
server_id=6
port=3306 
socket=/tmp/mysql.sock 
[mysql]
socket=/tmp/mysql.sock
EOF

4.6 Get ready MySQL The startup script

[root@m01 ~]# cd /app/database/mysql/support-files/
#  Copy mysql To the system software management directory 
[root@m01 support-files]# cp mysql.server /etc/init.d/mysqld
# centos6
[root@m01 ~]# service mysqld start 
Starting MySQL.Logging to '/data/3306/m01.err'.
 SUCCESS! 
 # centos7
 #  take /etc/init.d/mysqld Add to systemd In management 
[root@m01 ~]# chkconfig --add mysqld
[root@m01 ~]# service mysqld stop
Shutting down MySQL.. SUCCESS! 
[root@m01 ~]# systemctl start mysqld