Date Diff In a BETWEEN Gives a 00932?

Question

Good morning. This seems like a simple problem, but I can't find a solution in the forum or on Google. Can some wise Oracle SQL guru point me in the right direction?
This is what I'm trying to do:
...X BETWEEN '01-JUN-2006' AND ('30-NOV-2009' - 162)...but this gives an ORA-00932 error, inconsistent datatypes: expected DATE got NUMBER. I don't understand this; adding or subtracting an integer from a date shouldn't change its type, and doesn't seem to in other circumstances. I tried this next:
...X BETWEEN '01-JUN-2006' AND ('30-NOV-2009' - INTERVAL '162' DAY(3))I can't say I'm impressed with the implementation of intervals. The number has to be formatted as a string? The default precision is 2?? Anyway, this errors with ORA-30081, invalid data type for datetime/interval arithmetic. This error seems to be very elusive, none of a dozen sites gave any helpful info, and this very forum claims to have no topics with "30081".
In other databases I could use something like this:
...X BETWEEN '01-JUN-2006' AND DATEADD('d', '30-NOV-2009', -162))...but I can't find such a function.
I could calculate the net value of the second date before passing it to the query, but that really shouldn't be necessary. This isn't complicated! Any ideas? I'm running on Oracle 9.2, if it matters.
- J

Answer 1

Hi,
Don't forget that all DATEs include hours, minutes and seconds. When debugging a problem with DATEs you should always display them.
ALTER SESSION  NLS_DATE_FORMAT = 'DD-Mon-YYYY HH24:MI:SS';will make the default display include hours, minutes and seconds.
If you don't specify hours, minutes or seconds, they default to 0.
Why is this important?
Say you want to find orders placed between February 4 and 6 (inclusive) this year.
A common mistake is to say:
WHERE     order_date     BETWEEN      TO_DATE ('04-Feb-2009', 'DD-Mon-YYYY')
               AND      TO_DATE ('06-Feb-2009', 'DD-Mon-YYYY')Knowing that "x BETWEEN y AND z" returns TRUE when x=y or x=z you might think the expression above includes February 6. Actually, it only include the first second of February 6, and excludes the other 83,999 seconds.
That is, the expression above is equivalent to:
WHERE     order_date     BETWEEN      TO_DATE ('04-Feb-2009 00:00:00', 'DD-Mon-YYYY HH24:MI:SS')
               AND      TO_DATE ('06-Feb-2009 00:00:00', 'DD-Mon-YYYY HH24:MI:SS')To include orders placed at any time on February 6, you can say:
WHERE     order_date     BETWEEN      TO_DATE ('04-Feb-2009 00:00:00', 'DD-Mon-YYYY HH24:MI:SS')
               AND      TO_DATE ('06-Feb-2009 23:59:59', 'DD-Mon-YYYY HH24:MI:SS')or add 1 day to the end date, and do not include that point. This last technique is often used with parameters, for example:
WHERE     order_date     >= TO_DATE (:from_date, 'DD-Mon-YYYY')
AND     order_date     <  TO_DATE (:to_date,   'DD-Mon-YYYY') + 1