How to get distinct values from property in table using API?

[Szymon Katar]

Hello everyone,

I used to visit this forum from time to time, but I never thought I will ask for help.
I have a very interesting case. I am using Import Set Api to transfer Objects to table - let's name it TableA.
I've got some properties in it for example PropertyA, PropertyB, PropertyC.
I can only import object to table, if it's properties are already in the table.

Since I am working on validation software in my application I am looking for ways for returning from table possible distinct values for property.

I am trying to use quering, but it's highly inaffective (takes long time):
URL/api/now/table/TABLE_NAME?sysparm_fields=PROPERTY_NAME&sysparm_limit=1500

I am not asking for a solution, but maybe You can guide where should I look?

To make thinks worse, I am using a stagigng tables, so most likely after some time data are moved to other table.

Best regards,

[Hitoshi Ozawa]

Hi Szymon,

Not sure but if performance is a problem to query the table, may be it would be faster to create a Scripted REST API that would check the table before updating and ignore if the query doesn't return any record.

https://docs.servicenow.com/bundle/sandiego-application-development/page/integrate/custom-web-servic...

[Szymon Katar]

Hello Hitoshi,
Thanks for a reply. So in this scripted rest api I can define a query that will return me a list of distinct value from each property? I've read the documentation about it, but still not sure how it works - never used it before. 
BR