Debian安装MySQL

前排提醒：内存较小的Debian需要事先添加swap，否则会有卡死的风险。

安装MariaDB

Debian不支持MySQL，自带MariaDB源可以兼容，如需直接MySQL跳过此节。

apt update
apt install -y mariadb-server
systemctl start mariadb
systemctl enable mariadb

设置 root 密码：

mysql

ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
FLUSH PRIVILEGES;

MariaDB安装完毕并配置好密码后尝试导入原先MySQL 8导出的SQL：

root@hcss-ecs-58f8:/# mysql -u root -p < /20260414_backup/backup.sql Enter password: -------------- CREATE DATABASE /*!32312 IF NOT EXISTS*/ mysql /*!40100 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci */ /*!80016 DEFAULT ENCRYPTION='N' */ -------------- ERROR 1273 (HY000) at line 24: Unknown collation: 'utf8mb4_0900_ai_ci'

sed -i 's/utf8mb4_0900_ai_ci/utf8mb4_general_ci/g' /20260414_backup/backup.sql

mysql -u root -p < /20260414_backup/backup.sql

报错：ERROR 1050: Table ‘user’ already exists

导入的是 整个数据库（包含 mysql 系统库）

而 MariaDB 已经自带了：

mysql.user
mysql.db
mysql.tables_priv

所以冲突了，过滤掉 mysql 库：

grep -v "mysql." /20260414_backup/backup.sql > clean.sql

但是此法会过滤掉所需的数据库。建议安装原生MySQL

安装MySQL

卸载MariaDB

apt remove --purge -y mariadb-server mariadb-client
apt autoremove -y

wget https://dev.mysql.com/get/mysql-apt-config_0.8.29-1_all.deb
dpkg -i mysql-apt-config_0.8.29-1_all.deb

确认：
MySQL Server & Cluster (mysql-8.0) ← 选这个

apt update

MySQL 官方 GPG key 过期了

rm -f /etc/apt/trusted.gpg.d/mysql.gpg
wget https://repo.mysql.com/RPM-GPG-KEY-mysql-2022
gpg --dearmor < RPM-GPG-KEY-mysql-2022 > /usr/share/keyrings/mysql.gpg

修改 MySQL 源

vim /etc/apt/sources.list.d/mysql.list

找到类似：

deb http://repo.mysql.com/apt/debian/ bookworm mysql-8.0

改成：

deb [signed-by=/usr/share/keyrings/mysql.gpg] http://repo.mysql.com/apt/debian/ bookworm mysql-8.0

apt update

从 MySQL 官方仓库索引看，repo.mysql.com 现在已经提供了 RPM-GPG-KEY-mysql-2025，而你报错缺的是 B7B3B788A8D3785C 这把 MySQL Release Engineering 的签名公钥。官方仓库首页也能看到 2025 的 key 文件已经存在。

rm -f /usr/share/keyrings/mysql.gpg

wget https://repo.mysql.com/RPM-GPG-KEY-mysql-2025
gpg --dearmor < RPM-GPG-KEY-mysql-2025 > /usr/share/keyrings/mysql.gpg

apt update

现在开始安装MySQL