mysql> select@@version;
+-----------+
| @@version |
+-----------+
| 5.7.42    |
+-----------+
1 row in set (0.00 sec)

mysql> 

[root@zyl-server ~]#  cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
[root@zyl-server ~]# 
[root@zyl-server ~]# 

ldd --version

或者
rpm -q glibc

**查看當前系統(tǒng)中的libstdc++版本：**

strings /usr/lib64/libstdc++.so.6 | grep GLIBCXX
strings /usr/lib64/libstdc++.so.6 | grep CXXABI
strings /usr/lib64/libstdc++.so.6 | grep GLIBC
strings /usr/lib64/libstdc++.so.6 | grep GLIBCXX

rpm -Uvh mysql-shell-8.2.0-1.el7.x86_64.rpm --force --nodeps

mysqlsh --version

mysqlsh -uroot -p -S /tmp/mysqld.sock -e "util.checkForServerUpgrade()" 

[root@db-mysql ~]# mysqlsh -uroot -p -S /tmp/mysqld.sock -e "util.checkForServerUpgrade()" 
Please provide the password for 'root@/tmp%2Fmysqld.sock': ******
Save password for 'root@/tmp%2Fmysqld.sock'? [Y]es/[N]o/Ne[v]er (default No): 
The MySQL server at /tmp%2Fmysqld.sock, version 5.7.42 - MySQL Community Server
(GPL), will now be checked for compatibility issues for upgrade to MySQL
8.2.0...

1) Usage of old temporal type
  No issues found

2) MySQL 8.0 syntax check for routine-like objects
  No issues found

3) Usage of db objects with names conflicting with new reserved keywords
  No issues found

4) Usage of utf8mb3 charset
  Warning: The following objects use the utf8mb3 character set. It is
    recommended to convert them to use utf8mb4 instead, for improved Unicode
    support.
  More information:
    https://dev.mysql.com/doc/refman/8.0/en/charset-unicode-utf8mb3.html

  db_update - schema's default character set: utf8
  db_update.users.name - column's default character set: utf8
  db_update.users.email - column's default character set: utf8

5) Table names in the mysql schema conflicting with new tables in 8.0
  No issues found

6) Partitioned tables using engines with non native partitioning
  No issues found

7) Foreign key constraint names longer than 64 characters
  No issues found

8) Usage of obsolete MAXDB sql_mode flag
  No issues found

9) Usage of obsolete sql_mode flags
  Notice: The following DB objects have obsolete options persisted for
    sql_mode, which will be cleared during upgrade to 8.0.
  More information:
    https://dev.mysql.com/doc/refman/8.0/en/mysql-nutshell.html#mysql-nutshell-removals

  global system variable sql_mode - defined using obsolete NO_AUTO_CREATE_USER
    option

10) ENUM/SET column definitions containing elements longer than 255 characters
  No issues found

11) Usage of partitioned tables in shared tablespaces
  No issues found

12) Circular directory references in tablespace data file paths
  No issues found

13) Usage of removed functions
  No issues found

14) Usage of removed GROUP BY ASC/DESC syntax
  No issues found

15) Removed system variables for error logging to the system log configuration
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:
    https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-13.html#mysqld-8-0-13-logging

16) Removed system variables
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:
    https://dev.mysql.com/doc/refman/8.0/en/added-deprecated-removed.html#optvars-removed

17) System variables with new default values
  To run this check requires full path to MySQL server configuration file to be specified at 'configPath' key of options dictionary
  More information:
    https://mysqlserverteam.com/new-defaults-in-mysql-8-0/

18) Zero Date, Datetime, and Timestamp values
  No issues found

19) Schema inconsistencies resulting from file removal or corruption
  No issues found

20) Tables recognized by InnoDB that belong to a different engine
  No issues found

21) Issues reported by 'check table x for upgrade' command
  No issues found

22) New default authentication plugin considerations
  Warning: The new default authentication plugin 'caching_sha2_password' offers
    more secure password hashing than previously used 'mysql_native_password'
    (and consequent improved client connection authentication). However, it also
    has compatibility implications that may affect existing MySQL installations. 
    If your MySQL installation must serve pre-8.0 clients and you encounter
    compatibility issues after upgrading, the simplest way to address those
    issues is to reconfigure the server to revert to the previous default
    authentication plugin (mysql_native_password). For example, use these lines
    in the server option file:
    
    [mysqld]
    default_authentication_plugin=mysql_native_password
    
    However, the setting should be viewed as temporary, not as a long term or
    permanent solution, because it causes new accounts created with the setting
    in effect to forego the improved authentication security.
    If you are using replication please take time to understand how the
    authentication plugin changes may impact you.
  More information:
    https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password-compatibility-issues
    https://dev.mysql.com/doc/refman/8.0/en/upgrading-from-previous-series.html#upgrade-caching-sha2-password-replication

23) Columns which cannot have default values
  No issues found

24) Check for invalid table names and schema names used in 5.7
  No issues found

25) Check for orphaned routines in 5.7
  No issues found

26) Check for deprecated usage of single dollar signs in object names
  No issues found

27) Check for indexes that are too large to work on higher versions of MySQL
Server than 5.7
  No issues found

28) Check for deprecated '.<table>' syntax used in routines.
  No issues found

29) Check for columns that have foreign keys pointing to tables from a diffrent
database engine.
  No issues found

Errors:   0
Warnings: 4
Notices:  1

NOTE: No fatal errors were found that would prevent an upgrade, but some potential issues were detected. Please ensure that the reported issues are not significant before upgrading.

[root@db-mysql ~]#  mysqldump -hlocalhost -uroot -p --all-databases > /home/db_back_2024.sql
Enter password: 
[root@db-mysql ~]# cd /home/                 
[root@db-mysql home]# ll
total 872
-rw-r--r--  1 root   root     889253 Mar 20 20:25 db_back_2024.sql
drwx------  2 oracle oinstall    127 Mar 18 05:12 oracle
drwx------. 2 zyl    zyl          62 Mar 16 22:24 zyl
[root@db-mysql home]# cp /etc/my.cnf /home/5.7.37_my.cnf

[root@zyl-mysql home]# 

[root@db-mysql home]# systemctl stop mysqld

cd /usr/local/

mkdir mysql-5.7.42_bk

##全部備份 mysql目錄下的文件
cp -R mysql/* mysql-5.7.42_bk

### 或者直接壓縮
### tar -zcvf mysql-5.7.42_bk.tar.gz mysql
[root@db-mysql bin]# tar zcf mysql-5.7.42_bk.tar.gz mysql

cd /usr/local/mysql

rm -rf bin
rm -rf docs
rm -rf include
rm -rf lib
rm -rf README
rm -rf LICENSE
rm -rf share
rm -rf support-files
rm -rf man

cd /etc/init.d/
 
tar zcf mysqld_5.7.42.tar.gz mysqld
 
rm -rf /etc/init.d/mysqld

mkdir /root/mysql8.2.0-glibc

##解壓
tar -xvf mysql-8.2.0-linux-glibc2.28-x86_64.tar -C /root/mysql8.2.0-glibc

##繼續(xù)解壓 
cd /root/mysql8.2.0-glibc

tar -xvf mysql-8.2.0-linux-glibc2.28-x86_64.tar.xz

[root@db-mysql mysql8.2.0-glibc]# mv mysql-8.2.0-linux-glibc2.17-x86_64/* /usr/local/mysql

##修改文件權限

chown -R mysql:mysql /usr/local/mysql

cp /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld

vi /etc/init.d/mysqld

datadir=/usr/local/mysql/data
basedir=/usr/local/mysql

[root@db-mysql ~]# systemctl daemon-reload
[root@db-mysql ~]# 
[root@db-mysql ~]# systemctl start mysqld
[root@db-mysql ~]# 
[root@db-mysql ~]# systemctl status mysqld

mysql -u root -p

[root@db-mysql mysql]# mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 10
Server version: 8.2.0 MySQL Community Server - GPL

Copyright (c) 2000, 2023, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 

mysql> select@@version;
+-----------+
| @@version |
+-----------+
| 8.2.0     |
+-----------+
1 row in set (0.00 sec)

mysql> 

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| db_update          |
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.01 sec)

mysql> use db_update;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+---------------------+
| Tables_in_db_update |
+---------------------+
| users               |
+---------------------+
1 row in set (0.00 sec)

mysql> select * from users;
+----+---------+------+---------------------+
| id | name    | age  | email               |
+----+---------+------+---------------------+
|  1 | Alice   |   25 | alice@example.com   |
|  2 | Bob     |   30 | bob@example.com     |
|  3 | Charlie |   22 | charlie@example.com |
|  4 | David   |   28 | david@example.com   |
|  5 | Eve     |   35 | eve@example.com     |
+----+---------+------+---------------------+
5 rows in set (0.00 sec)

mysql>