I understand that you can package/deploy a database project from Visual Studio, but, does the database project produce an output that can be deployed using msdeploy, or are they totally unrelated? e.g. msdeploy.exe -deploy mydatabaseproject
Alternatively, maybe the dbproj just outputs scripts that can be included in the 'Package/Publish SQL' tab that will be included in the web deployment package and subsequently executed as part of the web deploy?
The build output from a DB project will be a SQL file that can be deployed using MSDeploy. In the project settings check out the "Deploy" page, it will lead you in the right direction. If you select the deployment action that both creates the script and deploys it MSDeploy will be used under the hood during your build process.