postgresql - SQL: Copy values for unique keys from one row to other

Question

I have table in following format:

Value in Date Field 1 could either be Null or some date value (which is appended every day). What I want is whenever for specific combination of ID1 and ID2, Date Field 1 is not Null, I want that value to be copied to other rows also as follows:

How do I do it?

Answer 1

Waitting for answers