tables_and_columns_postgre.sql

select s.table_name, s.column_name, s.data_type, s.character_maximum_length, s.ordinal_position, s.is_nullable, s.column_default, x.conname, x.rel_table
from information_schema.columns s
left join
(
                 SELECT p1.relname AS table, a1.attname AS column, c.conname, p2.relname as rel_table
                 FROM pg_constraint c, pg_namespace n, pg_class p1, pg_class p2, pg_attribute a1, pg_attribute a2,
                 pg_namespace n2
                 WHERE
                   c.contype = 'f'
                   AND c.confrelid > 0
                   AND c.connamespace = n.oid
                   AND c.conrelid = p1.oid
                   AND c.confrelid = p2.oid
                   AND c.conrelid = a1.attrelid
                   AND c.confdeltype = 'a'
                   AND a1.attnum = ANY (c.conkey)
                   AND c.confrelid = a2.attrelid
                   AND a2.attnum = ANY (c.confkey)
                   AND p2.relnamespace = n2.oid
                   AND n2.nspname = 'public'
) x  on x.table = s.table_name and x.column = s.column_name
where
   s.table_schema = 'public'