with ck as (select 
o.conname,
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table, 
c.oid as target_table_oid,
unnest(o.conkey) AS target_col,
cardinality(o.conkey) AS number_of_columns,
substring(pg_get_constraintdef(o.oid),7) as consrc
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype = 'c' and cardinality(o.conkey)>1),
ck_grouped as (
select ck.conname, ck.target_schema, ck.target_table, string_agg(a_target.attname, ',<br>'  order by  a_target.attnum) as target_col, ck.consrc, ck.number_of_columns
from ck inner join pg_attribute a_target on ck.target_col = a_target.attnum and ck.target_table_oid = a_target.attrelid and a_target.attisdropped = false
group by ck.conname, ck.target_schema, ck.target_table, ck.consrc, ck.number_of_columns)
select conname, target_schema as schema, target_table as table, target_col as columns, number_of_columns, consrc AS check_clause
from ck_grouped
order by target_schema, target_table, number_of_columns DESC;