【mysql错误 Mac】ERR_WHEN_INSERT_TO_DB\nError:Connection lost: The server closed the connection.

{"code":-1,"error":"ERR_WHEN_INSERT_TO_DB\nError: select count(`open_id`) as `hasUser` from `cSessionInfo` where `open_id` = 'oQPCO4ol5Y_-yL0MnCGxwbiHbSek' - Connection lost: The server closed the connection."}

这个是数据库查询报出的错误，所以我们先登录一下数据库，查询看看具体报错

#登录数据库
~/my-project/server$ mysql -uroot -p
Enter password:

#选择项目数据库名称，我的是cAuth
mysql> use cAuth;
Database changed

#查询选中数据库所有数据表
mysql> show tables;
#查询数据库所有数据表报错
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    8
Current database: cAuth

可以看出查询数据表的时候就报错了，出现错误​​MySQL server has gone away​​

这个错误的意思是mysql服务连接不上，运行​​brew services restart mysql​​重启一下mysql进程

# 重启 mysql
~/my-project/server$ brew services restart mysql

Stopping `mysql`... (might take a while)
==> Successfully stopped `mysql` (label: homebrew.mxcl.mysql)
==> Successfully started `mysql` (label: homebrew.mxcl.mysql)

重启mysql进程之后，再来启动项目试一下是否还报错，现在已经可以了。