How can I find all violations of a proposed foreign key on all columns with a specific name?

Let's say I have multiple tables with a column foobar. And I wish to make to make all these columns reference foobar.id as a FOREIGN KEY. The problem is **I know there are violations in this schema from the party I am importing the data from.** But, I would rather not find them all iteratively. How can I find all of the violations so as to prepare a report of data-integrity issues for the third party?