Unpivot query error

Question

Hi,
I am running an oracle 11gR2 Database.
I have a table of the structure..
CREATE TABLE "RP_RESOLUTION_MASTER"
( "RM_ID" NUMBER,
"SR_ID" NUMBER,
"REQUEST_STATUS" VARCHAR2(200 BYTE),
"COMMENTS" VARCHAR2(4000 BYTE),
"UPDATED_ON" DATE,
"UPDATED_BY" VARCHAR2(500 BYTE),
"INTERNAL_COMMUNICATION" VARCHAR2(1 BYTE) DEFAULT 'N'
I am running an unpivot query on this.
SELECT *
From Rp_Resolution_Master
Unpivot INCLUDE NULLS (
value For measures In ( rm_id, request_status, Comments
, updated_by, internal_communication)
where sr_id = 1004707
And Updated_On = ( Select Max(Updated_On)
From Rp_Resolution_Master
Where Sr_Id = 1004707);
But I get an error
ORA-01790: expression must have same datatype as corresponding expression
01790. 00000 - "expression must have same datatype as corresponding expression" *Cause:
*Action: Error at Line: 3 Column: 51
What is it that I am doing wrong here?

Answer 1

The columns you're trying to unpivot are not of the same datatype, hence the error.
You have to convert them to a common datatype first :
SQL> select empno, measure, val
  2  from scott.emp
  3  unpivot ( val for measure in (ename, sal) )
  4  where mgr = 7698
  5  ;
unpivot ( val for measure in (ename, sal) )
ERROR at line 3:
ORA-01790: expression must have same datatype as corresponding expression
SQL> with emp2 as (
  2    select empno
  3         , mgr
  4         , ename
  5         , to_char(sal) as sal
  6    from scott.emp
  7  )
  8  select empno, measure, val
  9  from emp2
10  unpivot ( val for measure in (ename, sal) )
11  where mgr = 7698
12  ;
     EMPNO MEASU VAL
      7499 ENAME ALLEN
      7499 SAL   1600
      7521 ENAME WARD
      7521 SAL   1250
      7654 ENAME MARTIN
      7654 SAL   1250
      7844 ENAME TURNER
      7844 SAL   1500
      7900 ENAME JAMES
      7900 SAL   950
10 rows selected.