Caused by: com.mysql.jdbc.PacketTooBigException: Packet for query is too large (1856352 > 1048576).
You can change this value on the server by setting the max_allowed_packet' variable.
因为mysql的默认设置通讯的数据包大小设置是１M,这就造成sql语句执行失败。
找到mysql的配置文件my.cnf【windows环境下是my.ini】
找到[mysqld]， 在这一行下面max_allowed_packet = 1M
修改为 max_allowed_packet = 16M
重起MySQL服务