Help with Nesting DECODE statements

Question

Hello. I'm trying to write a sql script to generate data report for payments. I need to incorporate specific conditions to SUPPRESS BLANK ADDRESS field lines. I am pulling Address_Line1, Address_Line2, Address_Line3, plus CITY, STATE, ZIP as Address_Line4. If any fields are blank, I need to suppress the blank line and move the other lines up.
Here are my IF, THEN, ELSE conditions. There are 9 possible scenarios that I have identified. Can you please help me write this in SQL with the DECODE function?
IF CITY||STATE||ZIP IS NULL               
THEN AD1='12115 Rainbow Road', AD2='Hartford Heights, MO 60226'               
ELSE               
     IF ADDRESS_LINE1 IS NULL          
          IF ADDRESS_LINE2 IS NULL     
               IF ADDRESS_LINE3 IS NULL
               THEN USE HOME ADDRESS
               ELSE vAD1=ADDRESS_LINE3, vAD2=CITY||STATE||ZIP
               ENDIF
          ELSE     
               IF ADDRESS_LINE3 IS NULL
               THEN vAD1=ADDRESS_LINE2, vAD2 = CITY||STATE||ZIP
               ELSE vAD1=ADDRESS_LINE2, vAD2=ADDRESS_LINE3, vAD3=CITY||STATE||ZIP
               ENDIF
          ENDIF     
     ELSE          
          IF ADDRESS_LINE2 IS NULL     
               IF ADDRESS_LINE3 IS NULL
               THEN vAD1=ADDRESS_LINE1, vAD2=CITY||STATE||ZIP
               ELSE vAD1=ADDRESS_LINE1, vAD2=ADDRESS_LINE3, vAD3=CITY||STATE||ZIP
               ENDIF
          ELSE     
               IF ADDRESS_LINE3 IS NULL
               THEN vAD1=ADDRESS_LINE1, vAD2=ADDRESS_LINE2, vAD3=CITY||STATE||ZIP
               ELSE vAD1=ADDRESS_LINE1, vAD2=ADDRESS_LINE2, vAD3=ADDRESS_LINE3, vAD4=CITY||STATE||ZIP
               ENDIF
          ENDIF     
     ENDIF          
ENDIF               
This what I've got so far...
DECLARE
  vADR1
  vADR2
  vADR3
  vADR4
BEGIN
SELECT
DECODE(
END;
/

Answer 1

Hi,
Here is the code along with some sample data. I substitute the "+" symbol for "/" becuase some addresses where using "c/o" in the address line.
The address fields are null, as shown by the query below (ref query results below):
SQL> select address_line1
  2  from po.po_vendor_sites_all
  3  where address_line1='3457 SOLUTIONS CENTER'
  4  and address_line2 is null;
ADDRESS_LINE1
3457 SOLUTIONS CENTERHere is the script:
WITH got_delimited_list AS
SELECT address_line1 || ' +' ||
address_line2 || ' +' ||
address_line3 || ' +' ||
city ||', ' || state ||'  ' || zip AS delimited_list
FROM po.po_vendor_sites_all
SELECT REGEXP_SUBSTR (delimited_list, '[^+]+', 1, 1) AS vad1
, REGEXP_SUBSTR (delimited_list, '[^+]+', 1, 2) AS vad2
, REGEXP_SUBSTR (delimited_list, '[^+]+', 1, 3) AS vad3
, REGEXP_SUBSTR (delimited_list, '[^+]+', 1, 4) AS vad4
FROM got_delimited_list;Sample of the data records returned:
VAD1
VAD2
VAD3
VAD4
3457 SOLUTIONS CENTER
CHICAGO, IL  60677-3004
VAD1
VAD2
VAD3
VAD4
5172 EAGLE WAY
CHICAGO, IL  60678-1517
VAD1
VAD2
VAD3
VAD4
RETAILERS' OCCUPATION TAX
SPRINGFIELD, IL  62796-0001
VAD1
VAD2
VAD3
VAD4
DEPT. NUMBER 478150
P.O. BOX 790100
ST LOUIS, MO  63179-9933
VAD1
VAD2
VAD3
VAD4
P.O. BOX 62251
BALTIMORE, MD  21264-2251
VAD1
VAD2
VAD3
VAD4
P.O. BOX 660481
DALLAS, TX  75266-0481
VAD1
VAD2
VAD3
VAD4
3525 PIEDMONT RD.
BUILDING FIVE
SUITE 300
ATLANTA, GA  30305