Why is the Ordered By disregarded?

Question

I want my SQL to return all records for a given date, with the most recent one on top (the column I'm ordering by contains both date and time - contains entries such as "5/21/2012 11:48:04 AM").

I would think my sql (below) would do this. However, the actual results disregard the time element. They are returned like this:

5/21/2012 10:48:04 AM
5/21/2012 10:12:04 AM
5/21/2012 9:48:04 AM
5/21/2012 10:54:04 AM
5/21/2012 11:48:04 AM
...

(IOW, the results returned are just randomly ordered, as far as the time element goes)

the query is:

SELECT ENTRYDATE ENTERED, ENTEREDBYABC ABC
FROM 
   SomeTable v 
   LEFT JOIN SomeTable w ON v.someCol = w.someCorrespondingCol
WHERE
   ABC = :abc AND ENTRYDATE = trunc(sysdate) 
ORDER BY ENTERED DESC

UPDATE

More specific query and results:

This (column and table names have been changed):

SELECT ENTRYDATE ENTERED, ENTEREDBYABCID ABCID, COMMENTS
FROM 
  WHITMAN.HOLLOWSKY@ATTORNEY v 
  LEFT JOIN ABCworker w ON v.enteredbyabcid = w.abcid
WHERE
  ABCID = 124393 AND ENTRYDATE = TRUNC(sysdate) 
ORDER BY ENTRYDATE desc

...returns records with:

ENTERED     ABCID   COMMENTS
5/21/2012   1234    At 1:36 PM, ...
5/21/2012   1234    At 1:36 PM, ...
5/21/2012   1234    At 9:23 AM, ...
5/21/2012   1234    At 11:07 AM, ...
5/21/2012   1234    At 11:12 AM, ...
5/21/2012   1234    At 1:42 PM, ...
5/21/2012   1234    At 11:02 AM, ...
5/21/2012   1234    At 9:19 AM, ...
. . .

UPDATED AGAIN

With the query:

select entrydate from WHITMAN.HOLLOWSKY@ATTORNEY order by entrydate desc

I get:

5/21/2012 3:15:50 PM
5/21/2012 3:15:35 PM
5/21/2012 3:15:25 PM
5/21/2012 3:15:25 PM
5/21/2012 3:14:31 PM
5/21/2012 3:14:22 PM
5/21/2012 3:14:11 PM
. . .

IOW, it works just fine.

Whether "entrydate" is a DateTime column - I reckon so, but I don't have privileges to look at the table structure, so ... ?

Answer 1

Your ORDER BY is being honored. The problem is that the time component on all 11 rows that you are selecting must be midnight in order to satisfy the predicate

entrydate = TRUNC(sysdate) 

The query

SELECT ENTRYDATE ENTERED, ENTEREDBYABCID ABCID, COMMENTS
  FROM WHITMAN.HOLLOWSKY@ATTORNEY v 
       LEFT JOIN ABCworker w ON v.enteredbyabcid = w.abcid
 WHERE ABCID = 124393 
   AND ENTRYDATE = TRUNC(sysdate) 
 ORDER BY ENTRYDATE desc

asks for all the rows where entrydate is today at midnight, then sorts on entrydate. By definition, since there is only one possible value for entrydate that satisfies the predicate, that ORDER BY is irrelevant. All 11 rows have exactly the same value for entrydate so sorting on that value produces an arbitrarily ordered result. Oracle could, quite correctly, return the 11 rows in any order and still be honoring your ORDER BY clause.

Perhaps you want to order by the time that is stored in the comments column rather than the entrydate. Perhaps you want to change your predicate to return all the rows where entrydate was some time today.

AND trunc(entrydate) = trunc(sysdate)

Perhaps you want to do something else.

Answer 2

I suspect the problem is that you have a column called "ENTERED" in one of the tables you are joining.

As a consequence, you are ordering by that column, even though it is not in the SELECT list. To fix this, you should do one of the following:

ORDER BY 1

or

ORDER BY ENTRYDATE

(The second having already been mentioned in Glenn's comment.)