Re: cast bit to boolean?

On Thu, May 03, 2001 at 05:25:14PM -0400, Vivek Khera wrote:
> How might one case a BIT to a BOOLEAN?  For example, I want to return
> rows which have non-zero bit representation for, say, (sel_a & b'0011').
> That is, rows with the first or second bit set.
>
> I tried an explicit CAST, and just the query directly, but the cast
> say you cant cast type 'bit' to 'bool', and the direct query says
> WHERE clause must return type bool, not type bit:
>
> create table t1 (sel_a BIT(6),sel_b BIT(6));
> insert into t1 values (b'000001',b'001000');
> select * from t1 where sel_a & b'100001';
> ERROR:  WHERE clause must return type bool, not type bit
>
> Where might I look for this?  The manual is quite sparse regarding BIT
> types.
>
> Thanks.

If you want only the rows where both bits are set then try:

select * from t1 where ( sel_a & b'100001' = b'100001' );

It seems that all bit files must be equal in length.