My usual diff-ing tool (BeyondCompare), allows me to pick which, from a list of differences, I want to go through to a final version. I guess you might call this more of a merge-conflict-resolver than a diff-tool.

What is great about this, is that when changes have been made on both sides, I can take the 'best of both', and make sure that those go through to the final output.

Now, you might say, 'how indisciplined', to have had changes on both sides. But I've found that here, as elsewhere, absolute discipline is an aspiration, but not the answer to business expediency.

I feel a bit hamstrung, in the SQL comparison window, that changes always travel from the source-to-target, and I'm not at liberty to say, 'yes, I want this change', 'no, I don't want that one'.