DAX help writing a calculated column

Hi!

I am trying to write a calc'd column and I feel like it should be simple but maybe im over-complicating it in my head.

I have 3 columns:

• Parent Lot #
• Lot #
• Sheet Lot #

And I want to basically just combine these columns because there are a lot of blanks with the way this query is set up.

I want to say:

Use Parent Lot #

If Parent Lot # is blank, use Lot #

If Lot # is blank, use Sheet Lot #

I tried doing this: but if lot # is blank it just uses the blank and ignores the last line.

Lot Number # = 
    IF(ISBLANK('Query'[Parent Lot #]), 'Query'[Lot #],
    IF(ISBLANK('Query'[Lot #]), 'Query'[Sheet Lot #], 'Query'[Parent Lot #])

How would I go about writing this?

Thanks a bunch!