MSBuild: automate collecting of db migration scripts?

Question

Summary of environment.

• Asp.net web application (source stored in svn)
• SQL Server database. (Database schema (tables/sprocs) stored in svn)
• db version is synced with web application assembly version. (stored in table 'CurrentVersion')
• CI hudson server that checks out web app from repo and runs custom msbuild file to publish/package app.

My msbuild script updates the assembly version of the web app (Major.Minor.Revision.Build) on each build. The 'Revision' is set to the currently checked out svn revision and the 'Build' to the hudson build number (incremented on each automated build).

This way i can match the app to a specific trunk revision also get other build stats from the hudson build number.

I'd like to automate the collecting of migration scripts (updated sprocs etc) to add to the zip package. I guess by comparing the svn revision of the db that has yet to be deployed to, to the revision being deployed, i can find what db files have changed in the trunk since the last deployment to that database/environment.

This could easily be achieved by manually calling the svn diff -r REVNO:REVNO command to list changed .sql files. These files could then manually have to be added to the package. It would be great if this could be automated.

Firstly i'd imagine I'll have to write a custom task to check the version of the db that has yet to be deployed to. After that I'm quite unsure. Does anyone have any suggestion on how this would be achieved through an msbuild task either existing or custom?

Finally I'll have to autogen a script to add to the package that updates the database version table so as to be in sync with the application.

Answer 1

Integrating SQL changes into an automated build/deploy process is HARD. I know, because I've tried to to it a couple times with limited success. What you're trying to do is roughly on the right track, but I would argue that it's actually a bit too complicated. In your proposal, you suggest collecting the specific SQL scripts that need to be applied to your DB at build/package time. Instead, you should package all your delta scripts (for the entire history of your database) with your project, and calculate the deltas that actually need to be applied when you deploy -- that way, your deployable package can be deployed to environments with databases of differing versions. There are two implementation pieces you need to achieve this:

1) You need to package your deltas into your deployable package. Note that you should package deltas -- not static files that create the schema in its current state. These delta scripts should be in source control. It's okay to keep the static schema in source control as well, but you will have to keep it in sync with the deltas. You can actually use a tool like Red Gate's SQLCompare or the VS Database version to generate (most) deltas from the static schema. To get the deltas into your deployable package, and given that you're using svn -- you may want to look into svn:externals as a way to "soft link" the delta scripts into your web project. Your build script can then simply copy them into your deployable package.

2) You need a system that can read the list of delta files, compare them to an existing database, determine which deltas need to be applied to that database, and then apply the deltas (and update the bookkeeping information, like the database version). There is an open-source project (sponsored by ThoughtWorks) called dbdeploy that accomplishes this. I've had some success with that tool personally.

Good luck -- this is a tough nut to crack (correctly).

Answer 2

Have a look at SQL database projects. In VS 2010 they have been enhanced quite a bit and have built in deployment capabilities that can sync your DEV database to other environments.

Here are a few good links about DB projects in vs 2010: http://msmvps.com/blogs/deborahk/archive/2010/05/02/vs-2010-database-project-building-and-deployment.aspx

http://weblogs.asp.net/gunnarpeipman/archive/2009/07/29/visual-studio-2010-database-projects.aspx