show VARIABLES like ‘%max_allowed_packet%‘;
显示的结果为：
+--------------------+---------+
| Variable_name | Value |
+--------------------+---------+
| max_allowed_packet | 1048576 |
+--------------------+---------+
修改max_allowed_packet值: 1048576 / 1024 / 1024 = 1M
原文：http://huangchao.blog.51cto.com/10446378/1730053