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,
unnest(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,
unnest(o.conkey) AS target_col
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.confmatchtype<>'f' and o.contype = 'f' and cardinality(o.confkey)>1),
fk_grouped as (
select fk.conname, fk.foreign_schema, array_agg(fk.foreign_table || '.' || a_foreign.attname order by  a_foreign.attnum) as foreign_col, fk.target_schema, fk.target_table, array_agg(fk.target_table  || '.' || a_target.attname  order by  a_target.attnum) as target_col, 
array_agg(a_target.attnotnull order by  a_target.attnum) as target_not_null 
from fk inner join pg_attribute a_foreign on fk.foreign_col = 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 = a_target.attnum and fk.target_table_oid = a_target.attrelid and a_target.attisdropped = false
group by fk.conname, fk.foreign_schema, fk.target_schema, fk.target_table)
SELECT format('ALTER TABLE %1$I.%2$I DROP CONSTRAINT %3$I;',  target_schema, target_table, conname) AS statements
from fk_grouped 
where not (target_not_null @> array['t']::boolean[])
order by target_schema, target_col;