Help! format of decode statements with between or signs ?

Question

Looking for an example of a decode statement with either a between/and or < > signs in the comparison field.
I have tried several variations, but none seem to work. Any help would be appreciated.
Here's a sample that doesn't work.
Select course_no, section_no, capacity, decode(capacity, (capacity < 12), Less than 12, (capacity between 13 and 15), 13-15, More than 15) from section;
Thanks in advance

Answer 1

Hi,
There is a limitation to the Case function, as it cannot be used in the PL/SQL (atleast upto Oracle 8i). Therefore, the only option left is Decode.
If you have to compare the values like capacity < 12 then display Less than 12. You can write it using combination of other functions.
For e.g. follow the steps below:-
1)If you deduct 12 from capacity : (capacity-12) [it will give result as +ve, 0 or -ve.]
2)If you have to narrow down the values to above three options, use function sign:
SIGN(capacity-12) [will result into +1, 0 or -1]
3)Then compare the values using Decode:
DECODE(SIGN(capacity-12),-1,Less than 12,Greater than or equal to 12)
The Decode can be used inside Decode(nested Decode) in above steps to compare more than one values (range between) to get the desired result. Hope have made it clear enough. If not, please let me know.
Cheers.
Yogesh D.