[Res] DB Connection string is not updated when changing env

This is a known issue. I personally submitted this as a defect, SmartBear acknowledged it, it's a low priority. If you have the -Pro license, contact them to vote it up.

The workaround that I use is to place the db server into a Project property, and then modify my connect string to look something like:
jdbc:mysql://${#Project#dbServer}:3306/schema
You can then modify the variable dbServer for each of your environments.

HTH