I'm a fan of the "Write as a SELECT first" method for any DELETE or UPDATE queries, but in my busier no-sleep days, I was very fond of mysql's --i-am-a-dummy switch[1] on the CLI client, which will "Permit only those UPDATE and DELETE statements that specify which rows to modify by using key values."
Although, these days, I generally avoid mucking around with production DBs directly. It's all manually scripted migrations, and testing said scripts on a backup or unused slave, which is by far the safest, and also helps to avoid running queries that might adversely affect production's performance.
Although, these days, I generally avoid mucking around with production DBs directly. It's all manually scripted migrations, and testing said scripts on a backup or unused slave, which is by far the safest, and also helps to avoid running queries that might adversely affect production's performance.
1: http://dev.mysql.com/doc/refman/5.7/en/mysql-command-options...