delete from comment where id=#{id} select c.id cid,c.username,c.email,c.content,c.avatar, c.create_time,c.forum_id,c.parent_comment_id from comment c, forum b where c.forum_id = b.id and c.forum_id = #{forumId} order by c.create_time desc insert into comment (username,email,content,avatar, create_time,forum_id,parent_comment_id, usercomment) values (#{username},#{email},#{content},#{avatar}, #{createTime},#{forumId},#{parentCommentId}, #{userComment}); select c.id cid, c.username, c.email, c.content, c.avatar, c.create_time, c.forum_id, c.parent_comment_id from comment c where c.parent_comment_id = #{parentCommentId} select id,username,email,content,create_time from comment