-- with explicitly specified not null constraints

create table inh_parent_1(f1 int);

create table inh_parent_2(f2 text);

create tablechild(f1 int not null, f2 text not null) inherits(inh_parent_1, inh_parent_2);

create tableinh_child(f1 int not null, f2 text not null) inherits(inh_parent_1, inh_parent_2);

NOTICE: merging column "f1" with inherited definition

NOTICE: merging column "f2" with inherited definition

-- show constraint info

select conrelid::regclass, conname, contype, coninhcount, conislocal

from pg_constraint where contype = 'n' and

conrelid in ('inh_parent_1'::regclass, 'inh_parent_2'::regclass, 'child'::regclass)

conrelid in ('inh_parent_1'::regclass, 'inh_parent_2'::regclass, 'inh_child'::regclass)

order by 2, 1;

conrelid | conname | contype | coninhcount | conislocal

----------+-------------------+---------+-------------+------------

child | child_f1_not_null | n | 0 | t

child | child_f2_not_null | n | 0 | t

conrelid|conname | contype | coninhcount | conislocal

-----------+-----------------------+---------+-------------+------------

inh_child | inh_child_f1_not_null | n | 0 | t

inh_child | inh_child_f2_not_null | n | 0 | t

(2 rows)

-- also dropschild table

-- also dropsinh_child table

drop table inh_parent_1 cascade;

NOTICE: drop cascades to tablechild

NOTICE: drop cascades to tableinh_child

drop table inh_parent_2;

-- test multi layer inheritance tree

create table inh_p1(f1 int not null);

createtableinh_parent_1(f1int);

createtableinh_parent_2(f2text);

createtablechild(f1intnot null, f2textnot null) inherits(inh_parent_1, inh_parent_2);

createtableinh_child(f1intnot null, f2textnot null) inherits(inh_parent_1, inh_parent_2);

select conrelid::regclass, conname, contype, coninhcount, conislocal

from pg_constraintwhere contype='n'and

conrelidin ('inh_parent_1'::regclass,'inh_parent_2'::regclass,'child'::regclass)

conrelidin ('inh_parent_1'::regclass,'inh_parent_2'::regclass,'inh_child'::regclass)

order by2,1;

droptable inh_parent_1 cascade;

droptable inh_parent_2;