Please back up the source data of the database before starting !!!
Please back up the source data of the database before starting !!!
Please back up the source data of the database before starting !!!

One 、 download mysql 8.0 My bag

• Offline installation is recommended to download zip Compressed package （ decompression , Use the administrator command line to configure ）
  Official website address ： https://dev.mysql.com/downloads/mysql/

• Use the installation package （ Double click installation , Select the component you want , Download and install automatically , To configure ）
  Official website address ： https://dev.mysql.com/downloads/installer/

Two 、zip Configure a new database after decompression

1. Open the management mode cmd perhaps powershell

   mysqld --initialize-insecure --user=root
   

2. Wait for execution to complete , It will take a while
   establish data Files such as folders
3. Create installation service

   mysqld install
   

4. Start the service

   net start mysql
   

   or(cmd Can be used directly in sc, powershell We need to use sc.exe)

   sc.exe start mysql
   

5. root Administrator login （ The default password is empty ）

   mysql -u root
   

3、 ... and 、zip The way is from 5.6 To upgrade to 8.0

This method requires two zip package , One hour 5.7 Intermediate version zip package , A target version 8.0 Of zip package .
as a result of ： By practice , 8.0 Version does not support from below 5.7 Version of mysql Upgrade directly to 8.0.
1. It is recommended that the following commands be directly passed through the administrator command line /powershell perform
2. Suppose your database starts as a service , And the service name is mysql

1. First step

from 5.6 To upgrade to 5.7：
1） stop it mysql service
mysqladmin -uroot -p shutdown or net stop mysql or sc stop mysql or Manually shut down
2） decompression 5.7 Of zip Package to source 5.6 The directory entry completely covers
3） start-up mysql service
4） perform mysql_upgrade -uroot perform 5.7 Upgrade program for
If root The user has a password , You need to add -p Parameters
5) If there is no error, start from 5.6 To 5.7 Upgrade Complete

2. The second step

from 5.7 Version upgrade to 8.0, Upgrade documents on the official website
1） Close the service
mysqladmin -uroot -p shutdown or net stop mysql or sc stop mysql or Manually shut down
2) decompression 8.0 Before decompressing and overwriting the compressed package 5.7 All files for
3） Start the service
4) Wait for the start to complete
8.0.16 Later versions are in the process of starting the service , It will automatically upgrade and update relevant data ;
otherwise You need to perform mysql_upgrade
5） If it starts normally , Then the upgrade is complete ; If there is no reference to relevant err Error message in file , Adjustment .

Four 、 Record of problems in the process

1. authentication plugin caching_sha2_password
   Because from 8.0 Then the password encryption rules changed (mysql_native_password -> caching_sha2_password)
   Use the original password ：
   alter user [email protected] identified with mysql_native_password by "root";

2. Unsupported redo log format (0). The redo log was created before MySQL 5.7.9

3. Cannot upgrade server earlier than 5.7 to 8.0
   These two questions , It can be solved through a solution ：
   Because my old version is 5.6 Not directly from 5.6 Update to 8.0, So according to the prompt , take 5.6 Update the version to 5.7 edition , After that 5.7 Update to 8.0 that will do .

4. Appoint my.ini Address time
   At this time, you should pay attention to the compatibility of configuration items , In case of incompatible configuration items , This will cause the service to fail to start ;
   Error messages can be found in bin In the directory mysqld Wrong err File log , Make relevant modifications according to the specified error information , Generally, it is directly commented out .