SELECT tc.constraint_name, tc.table_name, kcu.column_name, ccu.table_name AS foreign_table_name, ccu.column_name AS foreign_column_name, tc.is_deferrable,tc.initially_deferred FROM information_schema.table_constraints AS tc JOIN information_schema.key_column_usage AS kcu ON tc.constraint_name = kcu.constraint_name JOIN information_schema.constraint_column_usage AS ccu ON ccu.constraint_name = tc.constraint_name WHERE constraint_type = 'XXXXX' AND tc.table_name = 'XXXXX';
constraint_type有四种：UNIQUE、PRIMARY KEY、CHECK、FOREIGN KEY
