I'd say its doable but possibly challenging for some scenarios. Like if you're going into MS SQL you'd have to do Identity inserts. I'm sure there are tools that can ease the difficulty. I think its probably easier to go from MS SQL to MySQL than the other way around because its easy to insert values into identity columns with MySQL, no special syntax required, not positive but I think pgsql is easy to insert into identity columns too.

I've never done it with mojoportal, migrate data to a different platform, but I did migrate data from MS SQL into MySQL when I migrated my joeaudette.com site from Rainbow to mojoPortal.

Should be easier to change dbs in mojoportal since the tables are already defined the same.

I used SqlYog (Windows) to migrate, it let me write a query against an odbc connection to MS SQL very easily and insert based on the select from MS SQL.

Might be possible to go from any one to another by exporting csv files from the tables and importing them.

Another good tool that might come in handy is Aqua Data Studio, it can talk to all the different dbs, I haven't really dug into its features to know about migrating data but it wouldn't surprise me if it has an easy way to do it. Its free for personal use and reasonable priced for commercial use, runs on java so you can install it on windows or linux

Eventually I want to do away with the integer identity columns and use guids for all ids. This will make it easier to combine data from different mojo installations without clashing on ids.

Joe