ERROR 2006 (HY000): MySQL server has gone away

我的问题是语句太长了，修改max_allowed_packet的值：

mysql> show global variables like 'max_allowed_packet';

+--------------------+---------+

| Variable_name      | Value   |

+--------------------+---------+

| max_allowed_packet | 4194304 |              // 原来的字长

+--------------------+---------+

1 row in set (0.00 sec)

更改:

mysql> set global max_allowed_packet=1024*1024*16;

mysql> show global variables like 'max_allowed_packet';

+--------------------+----------+

| Variable_name      | Value    |

+--------------------+----------+

| max_allowed_packet | 16777216 |         //调整后的参数

+--------------------+----------+