Goal Find CHECK constraints that cover at least one column and that have been defined in a supertable (parent table) but not in its subtables. An entity that belongs to a subtype should also belong to its supertype. If a subtype entity satisfies some constraint, then logically it must also satisfy the constraints of the supertype as well. If CHECK constraints are not inherited, then this is not guaranteed. If you implement subtyping not merely reuse implementation in the subtables, then the subtables must have at least the same CHECK constraints as the supertable.
Type Problem detection (Each row in the result could represent a flaw in the design)
Reliability Medium (Medium number of false-positive results)
License MIT License
Data Source system catalog only
SQL Query
with constr as (select
o.conname as constraint_name,
(select nspname from pg_namespace where oid=c.relnamespace) as supertable_schema,
c.relname as supertable,
c.oid as supertable_oid,
o.conkey AS constraint_col,
pg_get_constraintdef(o.oid) AS constraint_def
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype='c' 
and connoinherit='true'),

constr_unnest as (select constraint_name, supertable_schema, supertable, supertable_oid, constraint_col, constraint_col_num, ordin, constraint_def
from constr, unnest(constr.constraint_col) with ordinality as f(constraint_col_num, ordin)),
constr_with_names as (select constraint_name, supertable_schema, supertable, array_agg(a_target.attname order by ordin) as constraint_col, supertable_oid, constraint_def
from constr_unnest constr left join pg_attribute a_target on constr.constraint_col_num = a_target.attnum and constr.supertable_oid = a_target.attrelid and a_target.attisdropped = false
group by constraint_name, supertable_schema, supertable, supertable_oid, constraint_def)
select constraint_name, supertable_schema, supertable, constraint_def, 
(select string_agg(pc.nspname || '.' || c.relname,';
' ORDER BY pc.nspname, c.relname) AS cols from pg_inherits pi inner join pg_class c on pi.inhrelid=c.oid inner join pg_namespace pc on c.relnamespace=pc.oid where pi.inhparent=constr_with_names.supertable_oid) as tables_without_the_constraint from constr_with_names order by supertable_schema, supertable, constraint_name;
Collections

This query belongs to the following collections:

NameDescription
Find problems automaticallyQueries, that results point to problems in the database. Each query in the collection produces an initial assessment. However, a human reviewer has the final say as to whether there is a problem or not .
Categories

This query is classified under the following categories:

NameDescription
CHECK constraintsQueries of this category provide information about CHECK constraints.
Table inheritanceQueries of this category provide information about the inheritance between base tables.