Difference between 2 date variables

Question

I have a query that selects data based on :
WHERE START_DATE >= &BEGIN
AND start_date <= &END
I need to find the difference between these 2 dates in order to use the result in a calculation in the totals area in a rtf I have, but don't know how to do a datediff with variables. Is it possible?
Thanks

Answer 1

You are running into a problem casting your character variables into dates. As you can see here, it is not such a good idea to let the database do this for you...
WITH temp AS
SELECT SYSDATE start_date FROM dual
SELECT *
FROM   temp
WHERE START_DATE >= &BEGIN
AND start_date <= &END + 1;
Enter value for begin: '01-dec-07'
old   7: WHERE START_DATE >= &BEGIN
new   7: WHERE START_DATE >= '01-dec-07'
Enter value for end: '01-jan-08'
old   8: AND start_date <= &END + 1
new   8: AND start_date <= '01-jan-08' + 1
AND start_date <= '01-jan-08' + 1
ERROR at line 8:
ORA-00932: inconsistent datatypes: expected DATE got NUMBERBut if you wrap the character strings with to_date()....
WITH temp AS
SELECT SYSDATE start_date FROM dual
SELECT *
FROM   temp
WHERE START_DATE >= to_date(&BEGIN,'DD-MON-YY')
AND start_date <= to_date(&END,'DD-MON-YY') + 1;
Enter value for begin: '01-DEC-07'
old   7: WHERE START_DATE >= to_date(&BEGIN,'DD-MON-YY')
new   7: WHERE START_DATE >= to_date('01-DEC-07','DD-MON-YY')
Enter value for end: '01-JAN-08'
old   8: AND start_date <= to_date(&END,'DD-MON-YY') + 1
new   8: AND start_date <= to_date('01-JAN-08','DD-MON-YY') + 1
START_DAT
18-DEC-07And to be absolutely correct, you should actually use a format mask with a full YYYY and supply a full year with your variables.
Greg