Oracle 10g sqlplus下如何查看table的primary key呢?

Question

Oracle 10g sqlplus下如何查看table的primary key呢? Example: 
SQL> create table test(
  2    id1 number primary key,
  3    id2 number,
  4    id3 number
  5  );
SQL> describe test;
 Name                                   Null?     Type
 -------------------------------------- ----------- ---------------------
 ID1                                   NOT NULL  NUMBER
 ID2                                                NUMBER
 ID3                                                NUMBER

Answer 1

SELECT  table_name,  constraint_name,  constraint_type    
   FROM  sys.user_constraints  
   WHERE  table_name='test'  看看是不是出来了?

Answer 2

select uc.TABLE_NAME,ucc.COLUMN_NAME
from user_constraints uc,user_cons_columns ucc WHERE uc.CONSTRAINT_NAME = ucc.CONSTRAINT_NAME and uc.TABLE_NAME=upper('tt1_record')
and constraint_type='P'