NVL FUNCTION IN A SUBQUERY

Question

I have the following query:

select E.EQUIPMENT_GID, NVL((SELECT SUBSTR(ES.STATUS_VALUE_GID,INSTR(ES.STATUS_VALUE_GID, '.')+1 ) FROM EQUIPMENT_STATUS ES  WHERE ES.EQUIPMENT_GID=E.EQUIPMENT_GID
AND ES.STATUS_TYPE_GID LIKE '%EQUIPMENT_STATUS' AND ROWNUM=1),'ZZZ') AS E_STATUS, NVL((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID
AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' and rownum=1),'ZZZ') AS PERM_DISTRICT_REF, 'PSKL-'||REPLACE(SUBSTR((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF
WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' AND ROWNUM=1),(INSTR((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF
WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' AND ROWNUM=1), '.',1,1) +1 )   ), ' PERMANENT DISTRICT','') AS DISTRICT_PSKL_XID, 
**SUBSTR(E.PARK_LOCATION_GID,5,11) AS PARK_LOCATION_GID** FROM EQUIPMENT E
WHERE E.EQUIPMENT_GID=?

Now i would like to check for null values and replace them with 'zzz' in my subquery SUBSTR(E.PARK_LOCATION_GID,5,11) AS PARK_LOCATION_GID

Can any one suggest solution to this one.

Answer 1

I got it, it should be:

select E.EQUIPMENT_GID, NVL((SELECT SUBSTR(ES.STATUS_VALUE_GID,INSTR(ES.STATUS_VALUE_GID, '.')+1 ) FROM EQUIPMENT_STATUS ES  WHERE ES.EQUIPMENT_GID=E.EQUIPMENT_GID
AND ES.STATUS_TYPE_GID LIKE '%EQUIPMENT_STATUS' AND ROWNUM=1),'ZZZ') AS E_STATUS, NVL((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID
AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' and rownum=1),'ZZZ') AS PERM_DISTRICT_REF, 'PSKL-'||REPLACE(SUBSTR((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF
WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' AND ROWNUM=1),(INSTR((SELECT EREF.EQUIPMENT_REFNUM_QUAL_GID FROM EQUIPMENT_REFNUM EREF
WHERE EREF.EQUIPMENT_GID = E.EQUIPMENT_GID AND EREF.EQUIPMENT_REFNUM_QUAL_GID LIKE '%PERMANENT DISTRICT%' AND ROWNUM=1), '.',1,1) +1 )   ), ' PERMANENT DISTRICT','') AS DISTRICT_PSKL_XID, 
NVL((SUBSTR(E.PARK_LOCATION_GID,5,11)),'ZZZ') AS PARK_LOCATION_GID** FROM EQUIPMENT E
WHERE E.EQUIPMENT_GID=?

Answer 2

Try this if you are using sql :

SUBSTR(ISNULL(E.PARK_LOCATION_GID, 'zzz'),5,11) AS PARK_LOCATION_GID