All identifying relationships

WITH fk as (select
o.conname,
(select nspname from pg_namespace where oid=f.relnamespace) as foreign_schema,
f.relname as foreign_table,
f.oid as foreign_table_oid,
o.confkey AS foreign_col,
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table,
c.oid as target_table_oid,
o.conkey AS target_col,
CASE WHEN o.confupdtype='a' THEN 'NO ACTION'
WHEN o.confupdtype='r' THEN 'RESTRICT'
WHEN o.confupdtype='c' THEN 'CASCADE'
WHEN o.confupdtype='n' THEN 'SET NULL'
WHEN o.confupdtype='d' THEN 'SET DEFAULT' END AS on_update,
CASE WHEN o.confdeltype='a' THEN 'NO ACTION'
WHEN o.confdeltype='r' THEN 'RESTRICT'
WHEN o.confdeltype='c' THEN 'CASCADE'
WHEN o.confdeltype='n' THEN 'SET NULL'
WHEN o.confdeltype='d' THEN 'SET DEFAULT' END AS on_delete
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
inner join pg_class f on f.oid = o.confrelid
where o.contype = 'f'),
fk_unnest as (select conname, foreign_schema, foreign_table,  foreign_table_oid, foreign_col, foreign_col_num, target_schema, target_table, target_table_oid, target_col, target_col_num, ordin, on_update, on_delete
from fk, unnest(fk.foreign_col, fk. target_col) with ordinality as f(foreign_col_num, target_col_num, ordin)),
fk_with_names as (select conname, foreign_schema, foreign_table, array_agg(a_foreign.attname order by ordin) as foreign_col, target_schema, target_table, array_agg(a_target.attname order by ordin) as target_col, on_update, on_delete
from fk_unnest fk inner join pg_attribute a_foreign on fk.foreign_col_num = a_foreign.attnum and fk.foreign_table_oid = a_foreign.attrelid and a_foreign.attisdropped = false
inner join pg_attribute a_target on fk.target_col_num = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false
group by conname, foreign_schema, foreign_table, target_schema, target_table,on_update, on_delete, target_col),

uq as (select
(select nspname from pg_namespace where oid=c.relnamespace) as target_schema,
c.relname as target_table,
c.oid as target_table_oid,
o.conkey AS target_col,
o.conname,
CASE 
WHEN o.contype='p' THEN 'PRIMARY KEY'
WHEN o.contype='u' THEN 'UNIQUE'
WHEN o.contype='x' THEN 'EXCLUDE'
END AS contype
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype in ('p','u','x')),
uq_unnest as (select target_schema, target_table, conname, contype, target_table_oid, target_col, target_col_num, ordin
from uq, unnest(uq.target_col) with ordinality as f(target_col_num, ordin)),
uq_with_names as (select target_schema, target_table, conname, contype, array_agg(CASE WHEN a_target.attname IS NOT NULL THEN a_target.attname ELSE 'something' END order by ordin) as target_col
from uq_unnest uq left join pg_attribute a_target on uq.target_col_num = a_target.attnum and uq.target_table_oid = a_target.attrelid and a_target.attisdropped = false
left join pg_type AS t_target ON a_target.atttypid=t_target.oid
WHERE a_target.attnotnull = true 
OR t_target.typnotnull=true
OR (a_target.attnotnull IS NULL AND t_target.typnotnull IS NULL)
group by target_schema, target_table, conname, contype)


select fk.conname, fk.foreign_schema, fk.foreign_table, fk.foreign_col, fk.target_schema, fk.target_table, fk.target_col, fk.on_update, fk.on_delete, uq.target_col as target_uq_col, contype AS target_uq_type
from fk_with_names as fk, uq_with_names as uq
where fk.target_schema=uq.target_schema
and fk.target_table=uq.target_table
and fk.target_col <@ uq.target_col
order by fk.target_schema, fk.target_table, fk.conname;