there is no doubt whether和there is no doubt that 的区别?

2.doubt+宾语从句
（1）在否定句和疑问句中,doubt后面接that引导的宾语从句.例如：
I don”t doubt that he can finish the task on time.我相信他能按时完成任务.
Do you doubt that she will succeed?你怀疑她会成功吗?
（2）在肯定句中,doubt后面一般接whether或if引导的宾语从句.例如：
I doubt whether they can swim across the river.我怀疑他们能否游过河去.
He doubts if she will keep her word.他不敢肯定她是否会遵守诺言.
注意：在肯定句中,doubt后面也可以接that引导的宾语从句,但表示疑虑较大或“不相信”.

there is no doubt that
这个是比较正确的用法。因为no doubt意思是毫无疑问。既然是毫无疑问，那接着一定要用that 来。
例：there is no doubt that my english is good.
我的英语好，这是毫无疑问的。
如果以whether来举例：
there is no doubt whether or ...