错误原因:
sql _mode中only _full _group _by不兼容的问题
解决思路:
既然是only _full _group _by不兼容,那就把它去掉就好啦
show variables like "sql_mode"; set sql_mode=''; set sql_mode='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION';