在mysql数据库中遇到的数据访问异常：GenericJDBCException:数据包查询太大(1211 > 1024)

org.springframework.web.util.NestedServletException:
Request processing failed; nested exception is org.springframework.orm.hibernate3.HibernateJdbcException:
JDBC exception on Hibernate data access: SQLException for SQL [n/a]; SQL state [S1000]; error code [0]; Packet for query is too large (1211 > 1024). You
can change this value on the server by setting the max_allowed_packet' variable.;
nested exception is org.hibernate.exception.GenericJDBCException:
Packet for query is too large (1211 > 1024). You
can change this value on the server by setting the max_allowed_packet' variable

当遇到这种方法我这里有一个简单易改的方法：

1.进入mysql server (mysql -u userName -p password)

2.在mysql 命令行中运行 (set global max_allowed_packet = 2*1024*1024*10)

3.退出mysql命令

4.重启mysql服务
5.在重新登录查询看是否修改成功 (show VARIABLES like '%max_allowed_packet%';)
[注：有时候此命令无效，需要使用这行命令：set @max_allowed_packet=5*1024*1024]