with keys as (select 
(select nspname from pg_namespace where oid=c.relnamespace) as key_schema,
c.relname as key_table, 
c.oid as key_table_oid,
o.conkey AS key_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype in ('u', 'p') and cardinality(o.conkey)=1),
keys_unnest as (select key_schema, key_table, key_table_oid, key_col, key_col_num, ordin
from keys, unnest(keys.key_col) with ordinality as k(key_col_num, ordin)),
keys_with_names AS (select key_schema, key_table, a_key.attname as key_col
from keys_unnest k inner join pg_attribute a_key on k.key_col_num = a_key.attnum and k.key_table_oid = a_key.attrelid and a_key.attisdropped = false
),
fk as (select 
(select nspname from pg_namespace where oid=c.relnamespace) as key_schema,
c.relname as key_table, 
c.oid as key_table_oid,
o.conkey AS key_col
from pg_constraint o inner join pg_class c on c.oid = o.conrelid
where o.contype='f'),
fk_unnest as (select key_schema, key_table, key_table_oid, key_col, key_col_num, ordin
from fk, unnest(fk.key_col) with ordinality as k(key_col_num, ordin)),
fk_with_names AS (select key_schema, key_table, a_key.attname as key_col
from fk_unnest k inner join pg_attribute a_key on k.key_col_num = a_key.attnum and k.key_table_oid = a_key.attrelid and a_key.attisdropped = false),
key_not_fk AS (select key_schema, key_table, key_col
from keys_with_names
except select key_schema, key_table, key_col
from fk_with_names)
SELECT format('ALTER TABLE %1$I.%2$I RENAME COLUMN %3$I TO %4$I;', c.table_schema, c.table_name , c.column_name, REGEXP_REPLACE(REGEXP_REPLACE(c.column_name, '_(nr|code|key)$', '_id'),'^(code|key|nr)_','id_')) AS statements
FROM information_schema.columns c
LEFT JOIN information_schema.domains d USING (domain_schema, domain_name)
INNER JOIN information_schema.schemata s
ON c.table_schema=s.schema_name
WHERE  (coalesce (c.column_default, d.domain_default) ILIKE '%nextval%'  OR c.is_identity='YES')
AND c.data_type IN ('smallint','integer','bigint')
AND c.column_name!~'^id_'
AND c.column_name!~'_id$'
AND (c.table_schema = 'public'
OR s.schema_owner<>'postgres')
AND EXISTS (SELECT *
FROM key_not_fk AS k
WHERE k.key_schema=c.table_schema
AND k.key_table=c.table_name
AND k.key_col=c.column_name)
ORDER BY table_schema, table_name;