Hopefully there's a solution/patch to SubSonic SimpleRepository where I can specify a column/property with a default value so that it populates the DB with the default value set.
I'm still reading the SubSonic Docs and just ran across that issue. Maybe someone has an answer/solution for this that I can start using.
Looks like you nailed it... In your class, simply set the default value in the constructor...
You could also set the value as a default in the appropriate DB column.
If you want a default value then set it on your object - an attribute shouldn't be used to set values.
To my knowledge this feature doesn't currently exist in SimpleRepository and in my opinion it doesn't belong there. I like the SimpleRepository because it's so simple. You don't need to know about or understand a ton of configuration options or attributes; you just plug in your POCO objects and go. There are a handful of attributes that you can use to influence the underlying database table schemas, but I think that a good job was done with respect to keeping those attributes to the absolute bare minimum needed.
If you need to set 'default' values for some reason I think that's something that should be done within your "domain" related code. Setting them in the constructor of the object might make sense, or using a wrapper repository object that could set them prior to passing along to the SimpleRepository could also work. I've always kind of thought that having default value constraints defined in the database was a bit of a smell anyway; it won't always be immediately evident where that value came from or why it was chosen.