[BUG]表连接发生错乱

不知道为什么，好像是，当我删除一个表，还是调删除键值的时候，外键表连接发生部分错乱！我不知道发生了什么？I don't know why, it seems, when I delete a table, or delete the key value, the foreign key table connection is partially disturbed! I don't know what happened.
Here is the original connection method。
product_img_lists,p_id--product_lists，p_id. and Chaotic connection article_lists,a_title,product_lists,p_id.