How are null DB values handled when accessed via a query rule?

RE: How are null DB values handled when accessed via a query rule?

anilkumark — Thu, 08 Sep 2016 22:38:20 GMT

How to implement NVL() in Appian? Can any one help me how to implement below query using queryEntity().

select * from REQUEST
where XYZ is null
and PQR is null
and NVL(NEW_CD, OLD_CD) IN (1,2,3);

RE: How are null DB values handled when accessed via a query rule?

Tim — Thu, 02 May 2013 01:43:46 GMT

I have seen java return a value of 0 when checking isnull against primitive int types so its quite possible this could be happening here. Maybe someone from Appian can confirm.

Null's can be tricky in RDBMS unless you're querying it natively. On our Oracle instances here I always use the NVL(column1, 999) type syntax rather than trusting or relying on a jdbc driver connection to do what I'd expect!

RE: How are null DB values handled when accessed via a query rule?

Jin Pheh — Thu, 02 May 2013 01:22:13 GMT

Sorry I should have been more clear. I'm running isnull() against a field on the CDT. The corresponding field in the DB is null though the other fields are present (primary key, etc)

RE: How are null DB values handled when accessed via a query rule?

Tim — Thu, 02 May 2013 01:19:37 GMT

You're either answering your own question or maybe I'm mis-reading it....

If you RDBMS table has a row the result of isnull will be false even if the value is null in the row.