MySQL won’t let you delete from a table using a subquery that references itself. Fair enough. To get around this, up till now, I’ve used temporary tables. However, I’ve never really liked it, and I’ve always wanted a JOIN delete. Well, apparently it exists.

I’m cleaning out some data from some really old database [...]

As of MySQL 5.0 there is no SHOW CREATE TRIGGER which is pretty annoying. I don’t like using “show triggers like
“, so I figured I’d write a wrapper around mysqldump. For the record, this was a huge pain the ass. I did this on Fedora, GNU sed version 4.1.5. You need to have [...]

Our sysadmin has a nice blog post with a few tips for using mysqldump, especially if your database is used for more than a basic site, or if you have stored procedures and/or triggers.

REPLACE INTO will actually perform a delete and then an insert, while INSERT … ON DUPLCIATE KEY UPDATE will perform an update (as the name suggests). I would think the latter would be faster. I have not done any performance testing between the two, but it only seems logical the update would be faster than [...]

For a long time, whenever I wanted to do paging to browse through a table, I used to run 2 queries. The first would get the results, and the second would be an almost identical query, with a count() instead of fields, and I’d use the result of the second query to figure out how [...]