jdbc4

09:00:30.307 [http-8080-6] ERROR org.hibernate.transaction.JDBCTransaction -JDBC begin failed com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet s...

今天访问已经架上服务器的网站，报错： Cause: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 78,050,512 milliseconds ago. ...

感谢大佬：https://blog.csdn.net/a704397849/article/details/93797529 springboot + mybatis多数据库 + druid连接池配置成功。正常运行后，访问第一个数据库后访问第二个数据库，再去访问第一个数据库 会报错...

sql报错： Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'blog.t_blog.addTime' which ...

排除 1.mysql 是utf8 2.连接url加了useUnicode=true&&characterEncoding=utf8 3.项目也没有用到utf8mb4 由于是mysql驱动版本5.1.30版本报错，换成5.1.6就好了 com.mysql.jdbc.exceptions.jdbc4.MySQLS...

一、问题  运行java代码时报如下的错误： you have an error in your sql syntax;cause:com.mysql.jdbc.exceptions.jdbc4.mysqlsyntaxerrorexception: check the manual that corresponds to your mys...

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Communications link failure during rollback(). Transaction resolution unknown. 这个问题当时是发生在我们软件使用人数突然激增的一...