OutSystems Advanced Queries

Use of comments (author: Marcel Lambrechts)

inSystems comments in code

I was creating an advanced query (see post OutSystems – Getting Database Information) for the DBCleaner application to display table space usage. When I executed the query in OutSystems Service Studio using the “Test” button, it gave a (the expected) result, so publish the application and go! Publishing the application went fine, but when I went to the page with the result of my query, it showed me an “Internal Error”.

Looking in ServiceCenter at the error, it told me that the error was ORA-00907: missing right parenthesis. Very strange to get an error on the syntax of the query, while testing the query in Service Studio worked like a charm.

Invalid commenting

After some puzzling it turned out that this error was due to some lines in the query I removed by commenting them using “–“. When I removed them the error disappeared. I started testing this with some other queries (a lot simpler) and whenever I use the “–” to comment something, Service Studio will gladly accept and run the query, but the platform will return with an internal error.

It turns out that the only acceptable way to add a comment in a query, for the OutSystems platform at least, is to use /* …. */.

So for example, the next query (using the — comment syntax) will result in an internal error:

SELECT
name,
— espace_id,
physical_table_name,
is_active
FROM ossys_entity;

And this query (using the /* */ comment syntax) will run fine:

SELECT
name,
/* espace_id, */
physical_table_name,
is_active
FROM ossys_entity;

Cause of the problem

The problem is caused by the fact that the OutSystems platform removes all Carriage Returns from the advanced querty, so the query with the “–” comment that I have listed above, will be translated by the runtime OutSystems platform to:

SELECT name, — espace_id, physical_table_name, is active FROM ossys_entity;

This way Oracle (and other database systems) will see everything after “–” as comment, thus including all other columns and the FROM clause.

Share this

Contact

Heb je vragen of opmerkingen? Aarzel niet om contact op te nemen. Dat kan via de algemene contactgegevens, rechtstreeks met de genoemde contactpersoon op een van de detailpagina’s, of via onderstaande knop.

9 februari 2026

Kan een AI goede queries schrijven?

AI is in korte tijd een vaste waarde geworden in het dagelijkse werk van software developers. Ook Oracle developers experimenteren steeds vaker met AI-tools om sneller en efficiënter SQL-queries te schrijven. Maar hoe goed werkt dat in de praktijk?

1 februari 2026

inSystems sponsor APEX World 2026

Ook dit jaar is er weer een APEX World. Voor de 16e keer organiseert de nlOUG deze conferentie, interessant voor iedereen die iets doet of wil met Oracle APEX. inSystems, partner van de nlOUG, is een van de sponsoren van dit event.

Opdrachten uitgevoerd voor

Ahold
VAA ICT Consultancy
inSystems KLM
Universiteit Tilburg
Feenstra inSystems
CB Logistics
RIGD LOXIA
Alphabet
CBR
Darling
Eneco
Nederlandse Spoorwegen
Allianz
Greenchoice
Stratech Social
Gemeente Gouda
Multi Tank Card
SVB
Ziggo
MN Services
Provincie Utrecht
TenneT
Ministerie van Economische Zaken, Landbouw & Innovatie
Syntrus Achmea Real Estate & Finance
Holland Casino
Arval BNP Paribas
Rechtspraak
Politie
Gemeente Apeldoorn
IBM
VTTI
Telegraaf Media Groep
WVDB Adviseurs Accountants
GVB
DICTU
AgroEnergy
NVWA inSystems
PC Uitvaart
UBR Uitvoeringsorganisatie Bedrijfsvoering Rijk
Van Iperen Groeispecialisten
TU Eindhoven
JUVA
Fokker
RAVU
Altran
inSystems Unive
Bank Mendes Gans
Thales
Leaseplan
Rabobank
ASR Nederland
Cannock
BMW
Gemeente Den Haag
Stedin
Oracle University
Rijk Zwaan inSystems
VION Food Group
Rendo
ING Bank