given this table:
if you want to return a default value 0 for ISRETRIABLE in case the ERRORCODE is missing in the table, you can do:
CREATE TABLE "ACME_ERRORCODES"
( "ERRORCODE" VARCHAR2(100 BYTE),
"ISRETRIABLE" NUMBER,
"ISCUSTOM" NUMBER
) ;
if you want to return a default value 0 for ISRETRIABLE in case the ERRORCODE is missing in the table, you can do:
select NVL (
(select ISRETRIABLE from ACME_ERRORCODES where errorcode = 'SOME_MISSING_ERROR_CODE' ),
'0')
from dual;