At Imaginet, we use Visual Studio Team Edition for Database Professionals (Data Dude) on our projects to manage database schemas, keep them in source control, unit testing, and lots of other nice features.
But it doesn't do database models well. Or at all, for that matter. I really would like the Database Diagramming tool in SQL Management Studio and Visual Studio to be able to go against a database project. But no, it can only go against an actual database.
Here is what we do to be able to model our tables and relationships with the diagramming tool and still use Data Dude.
For every project, we have a number of database "instances" - usually named after the project (I'll use the name Northwind from here on) with a suffix for the "environment", such as Northwind_Dev and Northwind_Test.
We also have another called Northwind_Schema, which is considered the "gold" standard for the schema of the project database. I'll start by creating that schema database and create tables in it using the database diagramming tool in SSMS. I can fairly quickly create a number of tables, and have a diagram for each subject area of the data. It also means my documentation is getting built at the same time as my database (in my world, the diagram forms the large part of the required database documentation). And these diagrams, like Xml comments in C# or VB, are also very close to "the code", and will keep current with the state of the schema database. Models created in other tools then exported to a database are very hard to keep accurate in the long run. When it comes time to snapshot the documentation for the database, we can fairly quickly embed pictures of the database models in Word or OneNote or some other documentation tool.
At the same time as I am modelling the database in Northwind_Schema, I create a database project in Visual Studio called Northwind. If I have the Northwind_Schema database in a state that I like (for first draft), I will use the Import Schema from Database wizard when creating the new database project. Otherwise, I'll just create an empty database project.
When I am happy with Northwind_Schema, I use a Schema Comparison to compare the Northwind_Schema database to the Northwind database project. I will update the database project with the changes that are in Northwind_Schema, then run any local tests against the database project before checking in.
Upon checkin, we have Team System automatically build the database and deploy it to Northwind_Dev, which is available for any developers on the project to use as they code other areas of the project. In the project I am working on now, we use LINQ and CSLA-based entities for our data access layer, so I will keep our LINQ model synchronized with the database project as well (usually by dragging tables onto the LINQ designer surface from the Northwind_Schema database).
If we ever lose Northwind_Schema, it is easy to rebuild it from the database project, because the database project in source control is "more true" than the Northwind_Schema instance. (However, we can lose the diagrams by rebuilding Northwind_Schema).
As I said above, I would actually prefer to do my diagramming in Visual Studio, against a database project rather than a database, and in that way I could also keep the diagrams in source control. But with the Northwind_Schema database, I can model new subject areas or do fairly major refactoring prior to checking out the database project files.
In my next post, I'll talk about how we build and manage stored procedures in project databases.