On 11/11/2020 06:44, Jitendra Loyal wrote:
> Consider this table definition:
> create table t ( i serial, b bool, c bool,
> constraint b_c check ( (b = true and c is not
> null ) or (b is distinct
> from true and c is null) )
> constraint b_c check ( (b = true and c is not
> null ) or (b = false and c
> is null) or (b is null and c is null) )
> );
> Despite the above two constraints, the following rows get into the table:
> insert into t (b , c) values (null, true), (null, false);
(b =TRUE AND c IS NOT NULL) evaluates to null when b is null
Cheers,
Chris Sterritt