제약조건 보기

select  	a.constraint_name, 
			a.table_name, 
			a.column_name, 
			a.position,
			b.constraint_type, 
			search_condition,
			r_owner, r_constraint_name, 
			status
from user_cons_columns a, user_constraints b
where a.constraint_name = b.constraint_name
and a.table_name = '&table_name'