SQL & PL/SQL

I have this select:

SELECT PCMS_CHDOC_THIS_ACTION_DESC.FILE_VERSION,
PCMS_CHDOC_THIS_ACTION_DESC.DATA

FROM ..........

LEFT JOIN PCMS_CHDOC_THIS_ACTION_DESC ON

......

WHERE ....

I would like tu use one of the following functions: ISNULL, COALESCE, IFNULL (the one is better), in the case that the returned value is NULL and in this case that print a string such 'No record Found'.

FILE_VERSION is a field number instead DATA is a CLOB.

I tried tio use then as ISNULL(PCMS_CHDOC_THIS_ACTION_DESC.FILE_VERSION, 'No Record found')

but it returned me an error saying "invalid identifier"

How can i write it?

Thanks

:)