ALTER TABLE `is_training_work_user_answer` ADD COLUMN `turns` int(5) DEFAULT '1' COMMENT '轮次';

ALTER TABLE `is_training_paper`
ADD COLUMN `is_auto_read`  int(2) NULL COMMENT '问答题是否系统自动审批' AFTER `is_all_answer`;

ALTER TABLE `is_training_work_reviewer` ADD COLUMN `user_answer_id` int(11) DEFAULT NULL COMMENT '作业记录id',
add index index_user_answer_id (user_answer_id);

ALTER TABLE `is_training_work_document` ADD COLUMN `thumb_url` varchar(200) DEFAULT NULL COMMENT '视频缩略图';