Around 15 years ago, I was packing up getting ready to leave for a long weekend. One of our marketing people I was friends with comes over with a quick change t

Around 15 years ago, I was packing up getting ready to leave for a long weekend. One of our marketing people I was friends with comes over with a quick change to a customers site. I had access to the production database, something I absolutely should not have had but we were a tiny ~15 person company with way more clients than we reasonably should have. Corners were cut. I write a quick little UPDATE query to update some marketing text on a product and when the query takes more than an instant I knew I had screwed up. Reading my query, I quickly realize I had ran the UPDATE entirely unbounded and changed the description of thousands and thousands of products. Our database admin with access to the database backups had gone home hours earlier as he worked in a different timezone. It took me many phone calls and well over an hour to get ahold of him and get the descriptions restored. The quick change on my way out the door ended up taking me multiple hours to resolve. My friend in marketing apologized profusely but it was my mistake, not theirs. As far as I remember we never heard anything from the client about it, I put that entirely down to it being 5pm on Friday of a holiday weekend.