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

Passing in any value that’s greater than 0 to this expression will yield a 1 every time. In order to do what you want, you need to round the results yourself:

select convert(bit, round(1*rand(),0))

This will give you a random 0 or 1 bit value.