How to pass in a List of parameters to query_parameters

Question

Hi, I have the following simple query in a Java application

declare query_parameters(pointNames:dynamic); CurrentData | where Point in (pointNames)

pointNames is a Java list of strings e.g. "TestSite1:11kV:Cb1:Amps", "TestSite2:11kV:Cb22:Voltage", etc etc

I'm using the kusto-data jar library version 5.0.0 and attempting to set the parameters with the following: -

clientRequestProperties.setParameter("pointNames", pointNamesList);

This doesn't work. Is there a way to set parameters for an IN clause in KQL with a list/array of strings?

Thanks Mark

Answer 1

Hi Annu,

The problem with your answer is there won't be a fixed number of pointNames as it is a Java List of Strings. Therefore the number of requested points could be 1, it could be 8, it could be 100 etc.

I've spent a few hours working on this and came up with this solution which works

var pointList = pointNames.stream().collect(Collectors.joining("','", "dynamic(['", "'])"));
var clientRequestProperties = new ClientRequestProperties();
clientRequestProperties.setParameter("pointList", pointList);
var query = """
		declare query_parameters(pointList:dynamic);
		let pointNames = pointList;
		CurrentData 
		| where Point in (pointNames)
		""";
return kustoClient.execute("MyDB", query, clientRequestProperties);

The Collectors.joining(delimiter, prefix, suffix) creates a kusto dynamic array in the format: -

dynamic(['point name1', 'point name2', 'point name3'..... , 'point nameX'])

which can be passed into query as a dynamic type

Regards

Mark

Answer 2

Hi MarkL ,

Welcome to Microsoft Q&A platform and thanks for posting your question here.

From the description of your question, it seems you are trying to figure out the way to use multiple selections in query parameters in data explorer.

Please let me know if that is not the correct understanding.

You can use 'in' clause in KQL for specifying multiple selections in KQL. . For that, you need to declare multiple parameters in the query parameter list

declare query_parameters(pointName1:string ,pointName2:string);
QnaCsatData
| where Point in (pointName1,pointName2)

Press Alt+P to provide values to these parameters.

Hope it helps. Kindly accept the answer by clicking on Accept answer button. Thankyou