T-SQL: How do I create a unique key that is case sensitive?

Question

How do I create a unique constraint on a varchar field that is case sensitive (SQL Server 2005)?

Currently my constraint looks like this:

Answer 1

You can only set the case-sensitivity of the data in the database (smallest granularity of column). You can't set case-sensitivity of an index - that would be equivalent to being able to index on an expression, which is possible in some databases but not Sql Server.