Composite key cannot allow bit column

Made an interesting discovery today - a column of data type Bit is not allowed to participate in composite key. Rather surprised.

I have a certain unique code that exhibits 2 unique states, which rendered the use of the boolean column, so the uniqueness goes <code>-1 and <code>-0. Is there any 'hack' so to speak to avoid using a Tinyint for the boolean column instead?Perhaps instead you could use a unique constraint composed of the 2 columns.

Terri|||I'm sure its not a good idea to use a field with so few values as a part of key. I think the tree tranversal will be impacted and your performance will suffer.|||Well, SQL Server won't allow me to use it as a key, so no "worries" on that. I will try Terri's unique constraint suggestion later.|||Unique constraints don't allow bit columns to participate either. Sigh.|||Actually, I'm sorry, what I meant was a unique index! I had tried that out before posting and it did not give me an error.

Terri