Need UPDATE MySQL help with Pings

Somehow, probably when trying to turn off pings during my test phase, I have several hundred posts with blank in the ping_status field of my wp_posts table.

I’ve tried different variations using the UPDATE command in MySQL, but I can’t find “anything” when there is nothing to replace, since there is nothing there.

Any ideas on how to search and replace these within the database so I don’t have to go through and manually change them all?

Here is one of the commands with “nothing” as the search that I tried:

UPDATE wp_posts SET ping_status=open
WHERE ping_status='';