Thanks Nikolay I read that but is there a way to meet the above requirement. And I will like to add that IS NULL and IS NOT NULL should evaluate to true/false. These operators are made for this and should not be returning NULL.
Regards, Jitendra On Wed 11 Nov, 2020, 14:18 Nikolay Samokhvalov, <samokhva...@gmail.com> wrote: > On Wed, Nov 11, 2020 at 12:26 AM Jitendra Loyal <jitendra.lo...@gmail.com> > wrote: > >> Despite the above two constraints, the following rows get into the table: >> insert into t (b , c) values (null, true), (null, false); >> > > This behavior is described in the docs > https://www.postgresql.org/docs/current/ddl-constraints.html#DDL-CONSTRAINTS-CHECK-CONSTRAINTS > : > > > It should be noted that a check constraint is satisfied if the check > expression evaluates to true or the null value. Since most expressions will > evaluate to the null value if any operand is null, they will not prevent > null values in the constrained columns. To ensure that a column does not > contain null values, the not-null constraint described in the next section > can be used. >
