Question

I am trying to transpose columns to rows using query similar to the following…

WITH 
query AS
(
    SELECT    SYSDATE AS SomeDate,
              'One' AS One,
              'Two' AS Two, 
              'Three' AS Three,
              'Four' AS Four,
              'Five' AS Five
        FROM dual
),
up_query AS
(
    SELECT * 
    FROM query
    UNPIVOT 
    ( 
     NUM FOR DUMMY 
     IN 
     ( 
      One AS 'One',
      Two AS 'Two',
      Three AS 'Three',
      Four AS 'Four',
      Five AS 'Five'
     )
    )
)
SELECT SYSDATE, b.*
  FROM up_query  b;

I was expecting SomeDate to reflect SYSDATE for the resulting rows…
But this is the result I am getting:

SYSDATE   SOMEDATE       DUMMY  NUM
09-DEC-11 09-DEC-07      One    One
09-DEC-11 09-DEC-07      Two    Two
09-DEC-11 09-DEC-07      Three  Three
09-DEC-11 09-DEC-07      Four   Four
09-DEC-11 09-DEC-07      Five   Five

Why is the SOMEDATE 4 years earlier than SYSDATE?

Answer 1

As Mark mentioned in his answer, this is a bug in Oracle 11.2.0.1 and 11.2.0.2 versions atleast.

However as per this article there is a workaround if you are stuck with the Oracle versions mentioned above, which is to convert the date to varchar format and then convert it back to date datatype.

So the query should now be:

WITH 
query AS
(
    SELECT     TO_CHAR(SYSDATE, 'RRRRMMDD') AS SomeDate,
              'One' AS One,
              'Two' AS Two, 
              'Three' AS Three,
              'Four' AS Four,
              'Five' AS Five
        FROM dual
),
up_query AS
(
    SELECT * 
    FROM query
    UNPIVOT 
    ( 
     NUM FOR DUMMY 
     IN 
     ( 
      One AS 'One',
      Two AS 'Two',
      Three AS 'Three',
      Four AS 'Four',
      Five AS 'Five'
     )
    )
)
SELECT SYSDATE, TO_DATE(SomeDate, 'RRRRMMDD') AS ActualSomeDate, b.*, 
  FROM up_query  b;