DAOProxy的代码:下面代码中红色高亮的就是出问题的地方,DAOFactory中会构造一个PersonDAOProxy,调用listPersons或者addPerson显然会导致递归,从而导致MySQL链接数溢出!将高亮处的代码修改为:dao.listPersons().dao.addPerson(person)即可! public class PersonDAOProxy implements IPersonDAO { private DatabaseConnection conn = n
1.外链接之左连接:优先显示左表全部记录 left join 在内连接的基础上保留左表的记录 即便左表有一条记录和右表没有关系,也把他留下 mysql> select * from employee left join department on employee.dep_id = department.id; +----+------------+--------+------+--------+------+--------------+ | id | name | sex | age
报错: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with exi
导致“mysql has gone away”的两种情况 By Cruise 1. wait_timeout参数 在开发代理server时, 我使用了jdbc连接数据库,并采用长连接的方式连接数据库.开发完后的测试ok,但到了第二天测试时发现数据库操作失败,并抛出“mysql has gone away”的异常,主要原因是在mysql中有一个wait_timeout参数,默认设置为8个小时,当超过8个小时没有数据交互时,mysql服务器会主动关闭掉超时的连接,对应的mysql 错误码是2006
豌豆夹Redis解决方式Codis源代码剖析:Proxy代理 1.预备知识 1.1 Codis Codis就不详细说了,摘抄一下GitHub上的一些项目描写叙述: Codis is a proxy based high performance Redis cluster solution written in Go/C, an alternative to Twemproxy. It supports multiple stateless proxy with multiple redis in
豌豆夹Redis解决方案Codis源码剖析:Proxy代理 1.预备知识 1.1 Codis Codis就不详细说了,摘抄一下GitHub上的一些项目描述: Codis is a proxy based high performance Redis cluster solution written in Go/C, an alternative to Twemproxy. It supports multiple stateless proxy with multiple redis insta