SQL how to keep multiple entries satisfying a certain condition

I have the following dataset:

ID  Amount
1   50
2   6
3   7
3   50
4   60
4   30
5   40
5   20

I only want to keep IDs with multiple entries that have at least one amount greater than, or equal to, 50. The final result would look like this:

ID  Amount
3   7
3   50
4   60
4   30

How would I go about doing this?

Answer

You can use windows function max as follows:

select * from
(select t.*, max(amount) over (partition by id) as max_
  from your_table t) t
where max_ >= 50