Thread:Project:Support desk/Updating multiple table prefixes at the same time?/reply

The "Database query error" you got from installing with shared db should probably be reported as a bug.

I have a similar so that I can use the same code for 3 different wikis. I just set the environment varialble  to the wiki I want. From the LocalSettings.php, I can set up the required DB, extensions, etc. for that wiki.

This allows me to run maintenance scripts for each wiki by running them with  set appropriately.

It sounds like this sort of setup would work for you, too.