Complex Decode Statement in Oracle

[nkshah]

I have one complex Decode statement that i can not able to understand it.

in the parameter it contains--> 1142009 <- as mmqyyyy formate.

Below is the code.

to_char(decode(substr('1142009',4,4),(to_char(sysdate,'yyyy')-2),
decode(substr('1142009',0,2),0,
decode(substr('1142009',3,1),0,12,
5,12,
1,03,
2,06,
3,09,
4,12,substr('1142009',0,2)),substr('1142009',0,2)),
decode(substr('1142009',4,4),(to_char(sysdate,'yyyy')-1),
decode(substr('1142009',0,2),0,
decode(substr('1142009',3,1),0,12,
5,12,
1,03,
2,06,
3,09,
4,12,substr('1142009',0,2)),substr('1142009',0,2)),
decode(substr('1142009',4,4),to_char(sysdate,'yyyy'),
decode(substr('1142009',0,2),0,
decode(substr('1142009',3,1),0,(to_char(r.reporting_date,'mm')-1),
5,to_char(r.reporting_date,'mm'),
1,03,
2,06,
3,09,
4,12,to_char(r.reporting_date,'mm')),substr('1142009',0,2))
,substr('1142009',0,2)))),'00') = pw.month_number <-----table column

Any kind of suggestion welcome.

Thanks.

 

[hilfy]

This is really an Oracle question and not a Crystal question. You will probably get a better response if you ask this question in an Oracle forum.

Having said that, here's what I would do:

Find the inner-most Decode from your nested decodes. Figure out what that is doing and then work your way "out" to the outer decode from there.

-Dell

A computer only does what you actually told it to do - not what you thought you told it to do.