mysql相关

Posted 2021-12-10 tianxie

 

启动tomcat,mysql提示连接数超过限制,

查询mysql最大连接数:  SHOW VARIABLES LIKE ‘%max_con%‘;

修改max_connections的值就可以了,超时时间过长也会导致连接数过多.

查询超时时间:   show global variables like ‘wait_timeout‘;

 

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查看用户授权语句:show grants for kitties;

查看某用户权限与host限制:  select * from mysql.user where user=‘kitties‘;

查看某用户数据库权限相关:select * from mysql.db where user=‘kitties‘

 

-----------------创建用户与授权------------------------

创建用户:

CREATE USER ‘用户名‘@‘ip限制‘ IDENTIFIED BY ‘密码‘;

例:CREATE USER ‘synchro‘@‘%‘ IDENTIFIED BY ‘password‘;

 

授权用户数据权限:

GRANT 操作权限 ON 数据库.表 TO ‘用户‘@‘host地址‘;

例: GRANT ALL ON lovecosmetictw .*  TO ‘synchro‘@‘%‘;

说明:授权该用户lovecosmetictw 数据库所有表添加,删除,等权限.

 

刷新数据到内存:

flush privileges;  

 

查看myslq版本: select version() from dual;