select decode(nullable,'Y','Optional','Mandatory'), a.COLUMN_NAME 
from all_tab_columns a, all_constraints b, all_cons_columns c
where a.TABLE_NAME = 'T_TONNAGE_WEIGHT_BREAK' 
  and a.owner = user
  and c.owner (+) = a.owner
  and c.table_name (+) = a.table_name
  and c.column_name (+) = a.column_name
  and b.owner (+) = c.owner
  and b.table_name (+) = c.table_name
  and b.constraint_type (+) = 'P'
order by decode(c.table_name,null,1,0), 
         nvl(c.position,a.column_id)
/

SQL> create table emp_sriram as select * from emp;

Table created.


SQL> alter table emp_sriram add  constraint pk_empno primary key(sal,empno);

Table altered.

SQL> ed
Wrote file afiedt.buf

  1   select a.table_name||','||b.column_name||','||a.constraint_name||','||a.constraint_type||','||a.r_constraint_name||','||count(*)
  2   from user_constraints a,user_cons_columns b
  3   where a.OWNER=b.owner
  4   and a.CONSTRAINT_NAME=b.CONSTRAINT_NAME
  5   and a.table_name=b.table_name
  6  and a.table_name in('EMP_SRIRAM')
  7  and a.constraint_type in('P','R')
  8  and a.table_name not like 'BIN%'
  9  group by a.table_name,b.column_name,a.constraint_name,a.constraint_type,a.r_constraint_name
 10* order by a.table_name,a.constraint_type,a.r_constraint_name
 11  /

A.TABLE_NAME||','||B.COLUMN_NAME||','||A.CONSTRAINT_NAME||','||A.CONSTRAINT_TYPE
--------------------------------------------------------------------------------
EMP_SRIRAM,EMPNO,PK_EMPNO,P,,1
EMP_SRIRAM,SAL,PK_EMPNO,P,,1

SQL> ed
Wrote file afiedt.buf

  1  select decode(nullable,'Y','Optional','Mandatory'), a.COLUMN_NAME
  2  from all_tab_columns a, all_constraints b, all_cons_columns c
  3  where a.TABLE_NAME = 'EMP_SRIRAM'
  4    and a.owner = 'SCOTT'
  5    and c.owner (+) = a.owner
  6    and c.table_name (+) = a.table_name
  7    and c.column_name (+) = a.column_name
  8    and b.owner (+) = c.owner
  9    and b.table_name (+) = c.table_name
 10    and b.constraint_type (+) = 'P'
 11  order by decode(c.table_name,null,1,0),
 12*          nvl(c.position,a.column_id)
SQL> /

DECODE(NU COLUMN_NAME
--------- ------------------------------
Mandatory SAL
Mandatory EMPNO
Optional  ENAME
Optional  JOB
Optional  MGR
Optional  HIREDATE
Optional  COMM
Optional  DEPTNO

8 rows selected.

SQL> desc emp_sriram
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 EMPNO                                     NOT NULL NUMBER(4)
 ENAME                                              VARCHAR2(10)
 JOB                                                VARCHAR2(9)
 MGR                                                NUMBER(4)
 HIREDATE                                           DATE
 SAL                                       NOT NULL NUMBER(7,2)
 COMM                                               NUMBER(7,2)
 DEPTNO                                             NUMBER(2)

SQL>

select *
from all_tab_columns tc
	left outer join (
			all_cons_columns cc
			join all_constraints c on (
				c.owner=cc.owner 
				and c.constraint_name = cc.constraint_name 
				and c.constraint_type='P'
			)
		)on (
			tc.owner = cc.owner 
			and tc.table_name = cc.table_name 
			and tc.column_name = cc.column_name
		)
order by tc.table_name,cc.position nulls last,tc.column_id

with cons_columns as (
-------
-- Optimized redefinition of DBA_cons_columns in order to avoid 
-- additional redudant joins
-------
		select /*+inline*/u.name as owner,                                         -- owner
			c.name as constraint_name,                                              -- constraint_name
			decode(cd.type#,2,'PRIMARY KEY',3,'UNIQUE',4,'FOREIGN KEY') 
				as constraint_type,                                                  -- constraint_type
			o.name as table_name,                                                   -- table_name
			col.name as column_name,                                                -- column_name
			cc.pos# as position                                                     -- ordinal position
		from sys.con$ c
			join sys.user$ u on (c.owner# = u.user#)
			join sys.cdef$ cd on (c.con# = cd.con# and cd.type# != 12 /* don't include log groups */)
			join sys.ccol$ cc on (cd.con# = cc.con#)
			join sys.col$ col on (cc.obj# = col.obj# and cc.intcol# = col.intcol#)
			join sys.obj$ o on (cc.obj# = o.obj#)
	)
select *
from dba_tab_columns tc
	left outer join cons_columns cc on (
			tc.owner = cc.owner 
			and tc.table_name = cc.table_name 
			and tc.column_name = cc.column_name
		)
where cc.constraint_type = 'PRIMARY KEY'
order by tc.table_name,cc.position nulls last,tc.column_id