I think at the method(stored proc) level defining constants as set @somevar=somevalue is easy to do, readable, and maintainable. I saw the earlier comment about module level constants and while not encouraged, they happen and often even make sense, and it's this area where SQL really has no option other than to table out the constants. Imagine that SQL had a built in CONST(constname) that worked in db scope, would we use it? I suspect some would, but in other cases the constant would probably be one more switch on some config table somewhere.

I guess - it being early and therefore being contrary - that I don't see what a .Net language does to help us in this case? Im not opposed to using the CLR where it fits, just not sure its valuable here.