Subject Return a unique key value in a string list
Author SoftTech
Greetings All,

Firebird 1.53

Inside a stored procedure I need to build a comma delimited string list
based on a custom notice ID and return it as a field on each record.

Let's say there are 500 records in the result set and I only want to place
unique values in the string list like 12,243,50,62,129 but of course there
are many records in the result set that could have the same custom notice
ID.

Here is an example of the first 6 records.
Notice records 1 and 3 are identical and records 5 and 6 have the same
NOTICE_ID but different CUSTOM_NOTICE_ID's

Record 1
NOTICE_ID: 255
CUSTOM_NOTICE_ID: 12

Record 2
NOTICE_ID: 267
CUSTOM_NOTICE_ID: 243

Record 3
NOTICE_ID: 255
CUSTOM_NOTICE_ID: 12

Record 4
NOTICE_ID: 288
CUSTOM_NOTICE_ID: 50

Record 5
NOTICE_ID: 301
CUSTOM_NOTICE_ID: 62

Record 6
NOTICE_ID: 301
CUSTOM_NOTICE_ID: 129

Currently the NOTICE_CUSTOM_ID_LIST field returned for the first result
would contain 12,243,12,50,62,129 and I would prefer 12,243,50,62,129
instead.

Does anyone know of a way to check if the string I'm building already
contains a value so it is not duplicated in the string list?

In other words by the time I process record 3 if '12' already exist in the
string '12,243', exclude it.

Any help truly appreciated,

Thanks,
Mike