check constraints
SELECT constraint_name, constraint_type, column_name, STATUS
from user_constraints natural join user_cons_columns
where table_name = 'XX';
SELECT *
FROM user_cons_columns
WHERE table_name = 'XX';
FROM user_cons_columns
WHERE table_name = 'XX';
for detalis need another sql
SELECT *
FROM user_constraints
WHERE table_name = 'XX'
AND constraint_name = 'XX';
FROM user_constraints
WHERE table_name = 'XX'
AND constraint_name = 'XX';