design for simplicity
Today I finally found a use case for querying multiple databases.
Within 1/2 hour of each other I had two different individuals affiliated with a Drupal site tell me that pages which were there yesterday weren't today. Investigation into the site didn't turn up anything but broken links.
I wanted to know how wide-spread the issue was. I mean, were the pages dropping like flies?
I thought it couldn't be done. I'd searched for it across the web. Terms such as mysql query multiple databases turned up nuthin' - that's right, not just nothing, but _flat-out_nuthin'_.
Today I was speaking with Matt Westgate of Lullabot about the challenges of managing 60+ Drupal web sites on a single codebase with each site having its own database, and Matt (who has a Drupal book coming out) mentioned liking MySQL for the fact that you could query multiple databases with a single query.
I'd looked for an equivalent to Find and Replace to use within SQL statements in MySQL for a while, and it wasn't until a few months ago that I came across the replace() string function. For whatever reason, I didn't find mention of this function or its application as easily as I would have liked, so perhaps this post will help the next guy or gal become aware of it.