ALTER TABLE `t_task_member`
ADD COLUMN `copy_seq` INT ( 11 ) DEFAULT '0' COMMENT '復制任務的序列號',-- 添加列
ADD COLUMN `user_task_start_time` datetime ( 6 ) DEFAULT NULL COMMENT '用戶任務開始時間',
DROP INDEX `unk_sub_task_id_shop_id_task_member_id`,-- 刪除索引
ADD INDEX `idx_sub_task_id` ( `sub_task_id` ) USING BTREE,-- 添加普通索引
ADD UNIQUE `unk_sub_task_id_copy_seq_shop_id_task_member_id` ( `sub_task_id`, `copy_seq`, `shop_id`, `task_member_id` ) USING BTREE;-- 添加唯一索引