gistfile1.txt

SELECT c.column_name, c.is_nullable, c.character_maximum_length, c.numeric_precision, c.numeric_scale, c.udt_name, tc.constraint_type
FROM ((information_schema.columns as c
INNER
	JOIN information_schema.constraint_column_usage as ccu
		ON c.column_name = ccu.column_name)
INNER
	JOIN information_schema.table_constraints as tc
		ON tc.constraint_name = ccu.constraint_name)
WHERE table_name = 'users';