How to generate only o or 1 for a bit column?

Question

I need to fill a bit column only with 0 or 1, I tried the following, which only gave me 1:

convert(bit, 2*rand())

How can I make it work?

Answer 1

If you need multiple rows, and you don't care about the specific distribution of values, something like the following may be appropriate:

CONVERT(bit,SUBSTRING(CONVERT(binary(18),newid()),1,1)&1)

This will be evaluated once per row