Getting affected rows before executing query?

I keep forgetting where clauses. It's my dumbest mistake, and I always make it. I just lost the password of everyone on my site trying to change my own - not good. Anyway, I'm trying to edit PhpMyAdmin to warn if there's more than a certain number of affected rows for a query. Is there a way to tell number of affected rows before executing the query? -- The above message is encrypted with double rot13 encoding. Any unauthorized attempt to decrypt it will be prosecuted to the full extent of the law.