安装Mysql的坑

ERROR 1146 (42S02): Table ‘mysql.role_edges’ doesn’t exist

用Mysql 8.0版本的会出这个问题,先强制你修改密码,然后修改密码过程中又出现这个错误,网上很多人说可以mysql_upgrade来修复系统表:

>mysql_upgrade -u root -p 

然而我的情况是,没有修改密码就无法升级表.这就陷入了一个死锁. 修复表->需要修改密码->缺少mysql.role_edges->需要修复表.

所以决定弃坑装mysql低版本

将mysql卸载干净

1. 卸载mysql

   yum erase mysql
   

2. 清除rpm包

   rpm -aq | grep mysql //查看还有哪些rpm包
   rpm -e packages  //一个个删干净
   

3. 清除系统中的残留

   find / -name mysql 
   rm -rf <directory>
   

安装低版本mysql

1. Download and add the repository, then update.

   wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm
   sudo rpm -ivh mysql-community-release-el7-5.noarch.rpm
   yum update
   

2. Install MySQL as usual and start the service. During installation, you will be asked if you want to accept the results from the .rpm file’s GPG verification. If no error or mismatch occurs, enter y.

   sudo yum install mysql-server
   sudo systemctl start mysqld
   

3. Change default password

   sudo mysql_secure_installation
   

C#中使用mysql

MySql.Data.MySqlClient.MySqlException (0x80004005): The host 127.0.0.1 does not support SSL connecti

原因是MySQL的dll不匹配 建议不要使用NuGet推荐的DLL 要使用MySQL自带的DLL导入即可解决.
根据本身服务器上的mysql版本来选择connector的版本,可以直接在NuGet包中选择版本第一点的包