Re: cast bit to boolean? - Mailing list pgsql-general

From Robert Hentosh
Subject Re: cast bit to boolean?
Date
Msg-id 20010503170814.D25704@fnord.io.com
Whole thread Raw
In response to cast bit to boolean?  (Vivek Khera <khera@kcilink.com>)
Responses Re: cast bit to boolean?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
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.


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