Return a specific value from another column if a condition is met

Hi there, I'm stuck at something in Excel so after some failed Google searches I've decided to appeal to solidarity here.

For example, if I assign number "1" to Room 8005 and I have another listing associating many objects with that room using the number 8005, I need to give those objects the number "1" too.
Imagine this procedure for hundreds of rooms and thousands of objects.

I know this process can be automated in Excel but I can't work it out.

I'm attaching a Excel file excel.xlsx that ilustrates what I intend to do, if anyone wants to lend me a hand, THANKS in advance.

Hi edward12

The attached does what you ask.

If the new_primarykey were to the right of the Room_number, you could have used vlookup.

Regards
Alastair

Originally Posted by aydeegee

Hi edward12

The attached does what you ask.

If the new_primarykey were to the right of the Room_number, you could have used vlookup.

Regards
Alastair

Thanks, you were extremely helpful.

Originally Posted by aydeegee

Hi edward12

The attached does what you ask.

If the new_primarykey were to the right of the Room_number, you could have used vlookup.

Regards
Alastair

Thanks, you were extremely helpful.

Hi edward12

Glad to have been of assistance. Perhaps you will mark this thread as "Solved"? To do this go to your first posting on this thread where you may amend the title.

Regards
Alastair