Is it possible to get just one row/record returned from a feature service query -- similar to the TOP, ROWNUM and LIMIT in database queries? Of course, OBJECTID "1" is not guaranteed. Is there a trick that I've missed?
SQL Server / Access: SELECT TOP 1 * FROM CUSTOMERS;
Oracle: SELECT * FROM CUSTOMERS WHERE ROWNUM <= 1;
MySQL: SELECT * FROM CUSTOMERS LIMIT 1;
PostgreSQL: SELECT * FROM CUSTOMERS LIMIT 1;
If you wanna to get only 1 record try use TOP statement.
ie:
OBJECTID IN (SELECT TOP 1 OBJECTID FROM 'customers' ORDER BY OBJECTID))
but you have note that this is bypass because TOP and LIMIT arent supported by geodatabase http://forums.arcgis.com/threads/68997-TOP-100
EDIT I digged deeper cause this subject seems to me as interesting, and I found this kind of script: http://resources.arcgis.com/gallery/file/geoprocessing/details?entryID=E780BB87-1422-2418-7FD8-A1A0D8167AAF it returns a subset of features with the same schema as oryginal. It's made in python so, maybe you could use it as geoprocessing service as gate to your sql queries.
EDIT2
From more research i think that using TOP LIMIT or ROWNUM depends on your DB engine. But the main clue is to use it as subquery - because we only can get access from WHERE part of statement by using API
NOTE FOR 10.2 USERS: This will not work because it defaults to standardized queries which don't allow subqueries. You can turn off standardized queries, but this is not recommended since it makes SQL injection attacks easier to perform.
sampleserver3, and I don't have access to my product. server right now so I can't check if its works. but it should, a can perform this kind of query in my arcgis desktop for query dispalying features from layer (arcgis desktop 9.3.1) so it should works the same on the server side... my arcgis desktop query is exact: OBJECTID IN (SELECT TOP 20 [OBJECTID] FROM [boreholes_db].[dbo].[DEEPBOREHOLESCLASS] ORDER BY NEWID())
– Krystian
Mar 4 '13 at 20:28
ORDER BY? – Krystian Mar 4 '13 at 19:23