1. 新建目錄：/opt/mysql，並cd進去

2.下載mysql安裝包：執行wget http://dev.mysql.com/get/mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar

3.解壓：執行tar -xvf mysql-5.7.26-1.el7.x86_64.rpm-bundle.tar

PS：centos7.6自帶的類mysql資料庫是mariadb，會跟mysql衝突，要先刪除。

4.查詢是否自帶資料庫：執行rpm -qa|grep mari，查詢mariadb相關安裝包

5.刪除自帶資料庫：執行rpm -e --nodeps mariadb-libs，解除安裝

6.然後開始真正安裝mysql，依次執行以下幾條

rpm -ivh mysql-community-common-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-libs-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-client-5.7.26-1.el7.x86_64.rpm

rpm -ivh mysql-community-server-5.7.26-1.el7.x86_64.rpm

注：libaio.so.1()(64bit) is needed by MySQL-server 問題解決辦法

[root@localhost upload]# rpm -ivh MySQL-server-5.5.25a-1.rhel5.x86_64.rpm
error: Failed dependencies:
libaio.so.1()(64bit) is needed by MySQL-server-5.5.25a-1.rhel5.x86_64
libaio.so.1(LIBAIO_0.1)(64bit) is needed by MySQL-server-5.5.25a-1.rhel5.x86_64

libaio.so.1(LIBAIO_0.4)(64bit) is needed by MySQL-server-5.5.25a-1.rhel5.x86_64

解決辦法：

yuminstalllibaio

7.啟動mysql:執行systemctl start mysqld.service

8.檢視root初始密碼：mysql自動給root使用者設定隨機密碼，執行grep "password" /var/log/mysqld.log可看到當前密碼

9.登入：執行mysql -u root -p，用root使用者登入，提示輸入密碼可用上述的，可以成功登陸進入mysql命令列

10.設定密碼：執行set password for 'root'@'localhost' =password('P@ssw0rd_2770');

11.執行flush privileges;使密碼設定生效.